EX-99.1 2 ex991.htm NI 43-101 TECHNICAL REPORT

 

Exhibit 99.1

 

 

 

 

 

AMC Mining Consultants (Canada) Ltd.

BC0767129

 

200 Granville Street, Suite 202

Vancouver BC V6C 1S4

Canada

 

T +1 604 669 0044

E vancouver@amcconsultants.com

W amcconsultants.com

 

 

 

 

 

 

 

 

 

 

 

 

Technical Report

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

Amapá (Brazil)

In accordance with the requirements of National Instrument 43-101 “Standards of Disclosure for Mineral Projects” of the Canadian Securities Administrators

Qualified Persons:

B Wolfe, MAIG

N Spicer, C.Eng.

M Batelochi, MAusIMM (CP)

R Lacourt, SME - RM

J Moreno, MIEAust, CPEng.

P O’Bryan, MAusIMM (CP)

R. Walton, P.Eng.

G Methven, P.Eng.

 

AMC Project 718060

Effective date 11 May 2018

Report date 31 October 2018

 

Unearth a smarter way

 

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Quality control

The signing of this statement confirms this report has been prepared and checked in accordance with the AMC Peer Review Process.

Project Manager The signatory has given permission to use their signature in this AMC document   31 October 2018
Gary Methven   Date
Peer Reviewer The signatory has given permission to use their signature in this AMC document   31 October 2018
Gary Methven   Date
Author The signatory has given permission to use their signature in this AMC document   31 October 2018
Carl Kottmeier   Date

Important information about this report

Confidentiality

This document and its contents are confidential and may not be disclosed, copied, quoted or published unless AMC Mining Consultants (Canada) Ltd. (AMC) has given its prior written consent.

No liability

AMC accepts no liability for any loss or damage arising as a result of any person other than the named client acting in reliance on any information, opinion or advice contained in this document.

Reliance

This document may not be relied upon by any person other than the client, its officers and employees.

Information

AMC accepts no liability and gives no warranty as to the accuracy or completeness of information provided to it by or on behalf of the client or its representatives and takes no account of matters that existed when the document was transmitted to the client but which were not known to AMC until subsequently.

Precedence

This document supersedes any prior documents (whether interim or otherwise) dealing with any matter that is the subject of this document.

Recommendations

AMC accepts no liability for any matters arising if any recommendations contained in this document are not carried out, or are partially carried out, without further advice being obtained from AMC.

Outstanding fees

No person (including the client) is entitled to use or rely on this document and its contents at any time if any fees (or reimbursement of expenses) due to AMC by its client are outstanding. In those circumstances, AMC may require the return of all copies of this document.

Public reporting requirements

If a Client wishes to publish a Mineral Resource or Ore / Mineral Reserve estimate prepared by AMC, it must first obtain the Competent / Qualified Person’s written consent, not only to the estimate being published but also to the form and context of the published statement. The published statement must include a statement that the Competent / Qualified Person’s written consent has been obtained.

 

amcconsultants.com

ii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

1Summary

This report has been prepared for Great Panther Silver Limited (GPR) in connection with the proposed acquisition (the Acquisition) by GPR of Beadell Resources Limited (BDR) pursuant to a Scheme Implementation Deed entered into between GPR and BDR on September 23, 2018. AMC Mining Consultants (Canada) Ltd. (AMC) has been retained by GPR to provide this Technical Report in accordance with National Instrument 43-101 (NI 43-101) “Standards of Disclosure for Mineral Projects”, of the Canadian Securities Administrators, to support the disclosure to be made by GPR regarding BDR’s Tucano Property (Property) including the Tucano Gold Mine in the information circular for the meeting of the shareholders of GPR to be held to approve the Acquisition.

1.1Project summary

The Tucano Gold Project is currently the 2nd largest gold producer in Brazil, producing around 145,000 oz per annum from several open pit mines in the northern state of Amapá, Brazil. Formerly a heap leaching operation, it ran from late 2005 until January 2009, producing approximately 292,000 troy ounces (oz) of gold from 8.8 million tonnes (Mt) of ore. The property was put under care and maintenance due to problems treating the increasingly transitional material. BDR acquired the property in 2010 and the process plant was upgraded with the addition of a SAG mill and carbon-in-leach (CIL) infrastructure, capable of treating sulphide ore. From November 2012 to 30 June 2017, 17.0 Mt at 1.34 g/t Au containing 735,294 oz Au were processed, feed was made up of a blend of pit oxide ore, sulphide ore, spent ore, and historic stockpiles.

GPR entered into a Scheme Implementation Deed dated 23 September 2018, that will result in the acquisition of all of the issued ordinary shares of BDR. Upon completion of the Acquisition, existing BDR and GPR shareholders are expected to own approximately 38% and 62%, respectively, of the combined company.

1.2Location

The Tucano Property is located at latitude 0.85°N and longitude 52.90°W in Amapá, the most north-eastern state of Brazil, approximately 15 km from the town of Serra do Navio. The mine is approximately 200 km from Macapá, the state capital, and is accessible by the Brazilian federal highway BR-210, or by chartered aircraft.

1.3Ownership

On completion of the Scheme Implementation Deed BDR will be wholly owned by GPR and through the wholly owned subsidiary, Beadell Brasil Limitada (Beadell Brasil), GPR will hold a 100% interest in the Tucano Property.

1.4Geology

The Tucano mineral deposits are located within the Guyana Craton, described by several authors as the Maroni - Itacaiunas mobile belt. This belt runs from Pará and Amapá States of northern Brazil through the Guyanas and into Venezuela. The regional structure is marked by a north-western trending foliation parallel to the main lithologic contacts. The western part of the Tucano property (about 25% of the area) is underlain by basement gneiss. The balance of the property area is underlain by ortho-amphibolite and meta-sedimentary rocks of the Vila Nova Group (1.75 to 1.9 billion years old), composed essentially of gneisses, granites, amphibolites, carbonates / calc-silicates, banded iron formations (BIF), schists, and quartzite. These units are intruded by granitic pegmatites, diabase dykes, and gabbro bodies.

amcconsultants.com

iii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

1.5Mineralization

Mineralization at Tucano is controlled by a major north-south shear zone. The texture and mineralogy along the shear zone indicates high-temperature hydrothermal alteration. This zone exhibits intense hydrothermal alteration, particularly silicification and sulfidation, bearing auriferous pyrrhotite, and pyrite. The alteration is most intense in the proximity of reactive meta-sediments such as BIF and carbonate and, to a lesser extent in calc-silicates, schists, and amphibolites. Late cross cutting intrusions are typically barren.

1.6History

Anglo American discovered a mineralized shear zone in 1994 and undertook extensive exploration between 1995 and 2002. AngloGold completed the initial feasibility study of the oxide resources in October 2002 and from this time until the acquisition of the project by BDR in 2010, regional exploration outside of the Tucano mining concession involved ground IP surveys, mapping, stream, soil, and auger sampling. In 2008 - 2009 a campaign of diamond drilling was undertaken in some of the regional exploration targets using a man-portable modular diamond drill rig.

1.7Drilling and exploration

After acquisition of the Property, BDR undertook an extensive resource delineation diamond drilling within the mining concession to improve and expand the resource base as part of the Feasibility Study (FS) for the CIL plant expansion. In 2012 BDR acquired a new T60 Schramm Reverse Circulation (RC) rig from Australia which was later sold to McKay drilling and continued operating on site under contract. The T60 Schramm is the main tool used for grade control drilling and resource extension holes, up to 400 m deep, and until now, has only been used to a limited extent to test regional exploration targets. Shallow testing of regional targets is currently done using motor driven auger drills and a track mounted blasthole rig that is very effective in penetrating the laterite profiles. BDR has undertaken an extensive review of geophysical, geochemical, and mapping datasets to generate a list of ranked targets which are the focus of the 2018 near mine and regional exploration program.

GPR is expected to benefit from near-term resource growth opportunities with multiple in-mine lease discoveries at Tucano and longer-term exploration optionality from BDR’s 2,500 square kilometre highly prospective land package, which is the property reported in this report (Property).

1.8Sample preparation and analysis

All sample preparation is done on site using separated sample preparation areas (one for mine grade control samples and one for resource infill and exploration samples). Grade control samples are analysed at the mine laboratory by 30 g fire assay with an atomic absorption spectrometer (AAS) finish. Exploration and resource holes were analysed at SGS Geosol Laborator’s in Belo Horizonte using 30 g fire assay with an AAS finish. An auditable chain of custody was established for the sample handling, data reporting, and data capturing using a Datashed SQL database. The reliability of the gold assay results was based on a well designed and implemented quality assurance and quality control protocol that includes the analysis of blanks, duplicates, and certified reference materials. Pulps from the mine laboratory are routinely sent to SGS Geosol to monitor its performance. Overall the laboratories returned acceptable results for the certified reference materials and blanks.

Based on this review work, the Qualified Person (QP) is of the opinion that the dataset provided by BDR is of an appropriate standard to use for resource estimation work. In the opinion of the QP the sample preparation, security and analytical procedures are adequate, and the data is fit for purpose.

amcconsultants.com

iv

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

1.9Mineral Resources

The Property contains an estimated Measured and Indicated Resource of 40.7 Mt at 1.71 g/t Au containing 2.24 Moz Au and an Inferred Resource of 16.4 Mt at 2.19 g/t Au containing 1.15 Moz Au (Table 1.1).

The Mineral Resources for the Property have been estimated by the following Qualified Persons (QPs) Mr Brian Wolfe, Principal Resource Geologist of International Resource Solutions Pty Ltd, takes responsibility for the Tap AB and Urucum estimates of the open pit MIK models and Mr Marcelo Batelochi, Principal Resource Geologist of Soluções em Geologia e Mineração Ltda, takes responsibility for the remaining estimates.

The Mineral Resources were estimated by a combination of Multiple Indicator Kriging (MIK) and Ordinary Kriging (OK).

For the purpose of reporting open pit Mineral Resources, the QPs tabulated the Mineral Resources within pit shells optimized using a gold price of US$1,500 per ounce of gold for the Tap AB and Urucum deposits.

The Mineral Resources have been reported in accordance with NI 43-101, and Definition Standards for Mineral Resources and Mineral Reserves adopted by the CIM Council on May 2014. Measured and Indicated Mineral Resources are inclusive of those Mineral Resources modified to produce the Mineral Reserves. A summary of the Mineral Resources as of 30 June 2017 are reported in Table 1.1.

It should be noted that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

Table 1.1 Summary of Mineral Resources as of 30 June 2017

Classification Tonnes (kt) Au grade (g/t) Contained Au metal (koz)
Measured 18,448 1.41 835
Indicated 22,293 1.96 1,405
Measured and Indicated 40,742 1.71 2,240
Inferred 16,351 2.19 1,150

Notes:

The June 2017 Tap AB UG Resource includes 173 kt at 4.68 g/t Au of Inferred Oxide within the Inferred Primary Category.
CIM Definition Standards (2014) were used for reporting the Mineral Resources.
Mr B. Wolfe, MAIG is the Qualified Person under NI 43-101 and takes responsibility for the Mineral Resource estimate for the Tap AB Open Pit and Urucum Open Pit Resource. Mr M. Batelochi, MAusImm (CP) is the Qualified Person under NI 43-101 and takes responsibility for all remaining resources.
Tap AB and Urucum open pit Mineral Resources are constrained by an optimized pit shell at a gold price of US$1,500 oz and using Measured, Indicated, and Inferred categories. The cut-off grade (COG) applied to the open pit resources is 0.5 g/t Au. The COG applied to ore stockpiles is 0.5 g.t with the exception of Marginal ore which has a COG of 0.3 g/t Au.
The underground COG is 1.2 g/t Au.
Drilling results are up to the 30 June 2017 for the Tap AB Open Pit resource. For all other deposits, drilling results up to the 31 December 2016, excluding the Urucum North Underground resource which has drilling results up to September 2015.
Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Mineral Resources are inclusive of their derived Mineral Reserves.
The numbers may not compute exactly due to rounding.

The QPs are not aware of any known environmental, permitting, legal, title, taxation, socioeconomic, marketing, political, or other similar factors that could materially affect the stated Mineral Resource estimates.

amcconsultants.com

v

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

1.10Mineral Reserves

Tucano Mineral Reserve estimates as of 30 June 2017 stated in this report are based on the Mineral Resources reported above and updated by Nigel Spicer of Minesure Pty Ltd. The Urucum underground Mineral Reserve was restated by AMC Consultants based on the PFS study completed in 2016 and in line with NI 43-101 guidelines. The cut-off grade (COG) used for the underground Mineral Reserves at Urucum was 1.6 g/t Au. The key modifying parameters for the optimized pit shells constraining the open pit reserves as at 30 June 2017 open pit Mineral Reserve estimates were made are summarized in Table 1.2.

It is noted that following reconciliation studies conducted in 2017, the modelling parameters for both Mineral Resource and Mineral Reserves are likely to be updated, which will be incorporated in the next Mineral Resource and Mineral Reserve estimate.

Table 1.2 Mineral Reserve key modifying parameters

Applied modifying parameters Urucum and Tap C Tap AB
Optimized March 2017 June 2017
Gold price US$1,100/oz US$1,150/oz
Royalty 2.00% 2.00%
Total process cost US$/t milled 10.71 - 14.34 9.98 - 14.1
Process Recovery 93 - 95% 93 - 95%
Mining + grade control cost US$/t milled 9.26 6.48
Mining dilution 15 - 20% 15 - 20%
Mining loss 0% 10%
Pit slopes 40 - 55 degrees 30 - 56 degrees
G&A cost US$/t milled 1.88 2.08
Mining in-situ Au COG 0.74 - 0.94 g/t 0.66 - 0.82 g/t

Based on the updated Measured and Indicated Mineral Resources for the various mineral deposits at Tucano, the total Proved and Probable Mineral Reserves using a gold price of US$1,200/oz for the open pit reserves and US$1,120 for the Urucum underground reserves, inclusive of stockpiles and as of 30 June 2017 is estimated to be 24.5 Mt at 1.79 g/t Au for 1.41 Moz of gold (Table 1.3). Open pit reserves for Tap AB and Urucum have been reported within pit designs optimized at a gold price of US$1,150/oz and US$1,100/oz respectively. The Mineral Reserves have also been reported in accordance with NI 43-101 and Definition Standards for Mineral Resources and Mineral Reserves adopted by the CIM Council on May 2014.

Exchange rates of US$ to the Brazilian Real (R$) used for the estimation of Mineral Reserves are discussed below Table 1.3.

 

amcconsultants.com

vi

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 1.3 Tucano gold operation - Mineral Reserves as of 30 June 2017

Brazil COG Proved Reserve Probable Reserve Total Mineral Reserve
Au (g/t)

Tonnes

(‘000)

Grade

Au (g/t)

Ounces

(‘000)

Tonnes

(‘000)

Grade

Au (g/t)

Ounces

(‘000)

Tonnes

(‘000)

Grade

Au (g/t)

Ounces

(‘000)

Urucum Open Pit oxide 0.7 374 1.21 15 180 1.18 7 554 1.20 21
Urucum East Open Pit oxide 0.7 0 0.00 0 151 1.71 8 151 1.71 8
Tap AB Open Pit oxide 0.6 2,384 2.16 166 2,024 1.76 115 4,408 1.98 280
Tap C Open Pit oxide 0.6 362 1.08 13 191 0.99 6 553 1.05 19
Total oxide open pit   3,120 1.92 193 2,545 1.66 136 5,666 1.80 329
Urucum Open Pit primary 0.8 4,446 1.69 241 5,246 1.81 306 9,692 1.76 547
Urucum East Open Pit fresh 0.7 0 0.00 0 16 1.50 1 16 1.50 1
Tap AB Open Pit primary 0.8 1,274 2.00 82 1,188 1.72 66 2,462 1.86 147
Tap C Open Pit primary 0.8 229 1.31 10 387 1.44 18 615 1.39 28
Total primary open pit   5,949 1.74 333 6,836 1.77 390 12,785 1.76 723
Urucum Open Pit total   4,820 1.65 256 5,425 1.79 312 10,245 1.72 568
Urucum East Open Pit total   0 0 0 167 1.69 9 167 1.69 9
Tap AB Open Pit total   3,658 2.10 247 3,212 1.75 181 6,870 1.94 428
Tap C Open Pit total   591 1.17 22 577 1.29 24 1,168 1.23 46
Total oxide and primary open pit   9,069 1.80 525 9,381 1.74 526 18,450 1.77 1,051
Open pit stockpile 0.5 1,985 0.66 42 0 0.00 0 1,985 0.66 42
Spent ore stockpile 0.5 1,311 0.61 26 0 0.00 0 1,311 0.61 26
ROM expansion stockpile 0.5 345 0.80 9 0 0.00 0 345 0.80 9
Total stockpiles 0.5 3,642 0.66 77 0 0.00 0 3,642 0.66 77
Total Tucano Open Pit & stockpiles   12,711 1.47 603 9,381 1.74 526 22,092 1.59 1,128
Urucum Underground primary   0 0.00 0 2,378 3.64 278 2,378 3.64 278
Total Underground primary   0 0.00 0 2,378 3.64 278 2,378 3.64 278
Grand total Tucano   12,711 1.47 603 11,759 2.12 804 24,470 1.79 1,406

Notes:

2018 Open Pit Mineral Reserves are stated as of 30 June 2017 based on the COGs as detailed in Table 1.3 above. Mineral Reserves are reported within open pit designs based on pit optimized shells using the following optimization COGs; Tap AB Oxide: 0.66 g/t Au, Tap AB Fresh: 0.82 g/t, Urucum Oxide 0.74 g/t Au, Urucum Fresh 0.94 g/t Au, Tap C Oxide 0.66 g/t Au, Tap C Fresh 0.86 g/t Au, Urucum East Oxide 0.74 g/t Au, and Urucum East Primary 0.94 g/t Au. The COG is based on total costs per pit (inclusive of processing, G&A, tech services and haulage, exclusive of mining costs) and averages US$12.8 for oxide and US$16.8 for fresh. Metallurgical recoveries are 95% for oxide and 93% for sulphides. The gold price used for the open pit optimizations was US$1,150/oz for Tap AB and US$1,100 for Tap C and Urucum. The gold price used to calculate the COGs for the reserves reported within the optimized pit designs was US$1,200 per ounce. An exchange rate of US$:R$ of 1:3.2 for Tap AB and 1:3.4 for Urucum was used. Open Pit Mining Recoveries of 100% for oxide and fresh were used at Urucum, 90% for oxide and fresh at Tap C and Tap AB and 90% oxide, 100% fresh at Urucum East. Dilution used for all pits was 15% for oxide and 20% for fresh.

 

amcconsultants.com

vii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

2018 Underground Mineral Reserves are stated as of 30 June 2017 and based on a COG of 1.6 g/t Au. The COG is based on an incremental mining and processing cost of US$50/t, metallurgical recovery of 90%, a gold price of US$1,120/oz and an exchange rate of US$:R$ of 1:3.8.
A 0.5 m dilution skin was assumed for the HW and FW side of the underground production stopes making the total dilution 1.0 m in width. Ore losses were assumed to be 8% for the Benching method, 14% for the Up-Hole retreat method, and ore losses for the recovery of the sill pillars were assumed to be 35%.
The JORC reserve released on 19 December 2017 to the ASX ("Interim Mineral Resource and Ore Reserve Update as at 30 June 2017") stated the total Urucum Underground Reserve was 2,972 kt at 3.61 g/t Au for 345 koz Au. This reserve was reported by AMC inclusive of Inferred resource blocks captured inside the stope designs that were optimized on Measured and Indicated Resources in the 2016 PFS. The Inferred Resources falling within the stope designs was removed from the calculations and reporting of the NI 43-101 compliant Urucum Underground Reserves by AMC Vancouver in 2018 and has been quoted in the Table 1.3 above.

 

 

amcconsultants.com

viii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

1.11Mining

The Tucano mine commenced operations in 2005 and continued as a heap leach operation until 2009 when it was placed on care and maintenance following processing problems caused by increasingly transitional ore. In 2010 BDR acquired the project and commenced construction of a CIL plant to add onto the existing process infrastructure. Mining and stockpiling of ore commenced in 2011 and the CIL plant was commissioned in November 2012. To date, 21.6 Mt at 1.31 g/t Au containing 912,690 oz Au has been processed made up of a blend of pit oxide ore, sulphide ore, spent ore, and historic low-grade stockpiles. Tucano uses a conventional open pit mining method, employing a new mine contractor Unienge & Modulo (U&M).

Underground mine

Access to site is well established as open pit mining operations commenced in 2012. The journey from the port town of Macapa takes approximately four hours by car during the dry season and up to six hours during the wet season. Access to the Urucum North underground mine would be via a portal located at the north end of the Urucum North pit.

BDR undertook a program of resource infill drilling below the Urucum North Pit. Most of these holes have been geotechnically logged for structural data. The geotechnical data logged from these holes has been analysed to provide preliminary estimates of stable stope development and pillar dimensions, using industry standard empirical techniques.

The mine layout is based on the following criteria:

Twin declines (north and south based on orebody strike length of >800 m.
Single access portal located at the northern end of the mine.
North and south exhaust rises.
Level interval of 20 m (based on 15 m production blastholes and the narrow width of some lodes).
Crosscuts between the decline and the mineralization, every 20 vertical meters (vm).
Access for decline development available in the Urucum North pit in January 2019.
Targeting Measured and Indicated Mineral Resources down to 500 mRL (750 mbs). The basis for the scheduling includes:
Focus on mining higher grade areas in 2021 and 2022.
Assume a top-down stope extraction sequence in upper levels to allow early production.
Assumes early development to the higher-grade areas in the lower levels where down-hole benching commences in a bottom-up orientation.

 

 

The Project sits below the Urucum North open pit and power is already available for the Urucum North underground mine. The underground mine will make use of the open pit mine’s existing explosives magazines and warehouse.

1.11.1Underground mine economics

 

Project capital is estimated at $44M; pre-production capital (Year 1) is estimated to be $10M. Sustaining capital ($34M) is defined as all capital following pre-production and includes ongoing mine development after production commences, and fixed equipment replacements and rebuilds over the mine life.

amcconsultants.com

ix

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Total site operating costs have been estimated at $88.67/t milled. The unit costs are broken down as follows:

Mining: $71.67/t milled
Milling and General and Administration: $17.00/t milled

The cost estimate and projected revenue were prepared with a base date of Year 1 and use constant Year 1 dollars (no inflation). For net present value (NPV) estimation, all costs and revenues are discounted at 5% from the base date. An exchange rate of US$:R$ of 1:3.8 and a royalty of 2% has been assumed, changes to the exchange rate affect labour costs only.

Revenues from gold production have been based on:

Metallurgical recovery of 90%
Gold royalty of 2%

AMC has conducted a pre-tax economic assessment of the Urucum North underground. Over an 8-year operating life, the mine is projected to generate approximately $25.5M pre-tax NPV at 5% discount rate, with a pre-tax internal rate of return (IRR) of 19.9%.

1.12Metallurgy and process plant

The Tucano processing plant uses a conventional carbon in leach (CIL) gold recovery process. The comminution circuit of the process plant is comprised of a primary jaw crusher, followed by a SAG mill. The milled product is processed in the CIL circuit where gold contained in the ore is leached and adsorbed onto activated carbon. The CIL tails slurry undergoes cyanide destruction prior to disposal in the tailings dam. Loaded carbon is rinsed prior to elution. A Pressure Zadra elution circuit is used to remove the gold from the loaded carbon and after which the rich solution flows through a bank of two electrowinning cells where the gold in the solution is deposited on the cathodes within the cells.

Following elution, the carbon is re-generated in the carbon re-generation kiln prior to being returned to the CIL circuit. The sludge containing the gold (which is weakly adhered to the cathodes) is dislodged with a high-pressure water spray and the sludge is dried in a drying oven before being direct smelted with fluxes in a furnace. The doré metal and slag separate in the furnace, the slag is poured off to slag pots and the doré metal is poured into bars. Doré bars are cleaned, weighed, stamped, sampled, and then stored in a safe, contained within a strong room, while awaiting dispatch.

With the current configuration of the grinding circuit, the plant can process up to 3.6 Mt per annum and a blend ratio of 80:20, oxide:sulphide. Increasing sulphide feed in future years meant that this blend ratio was not sustainable and in 2017 work commenced to expand the CIL plant to include a 6 MW ball mill, extra CIL tank, oxygen plant, and pre-leach thickener. The aim of this was to accommodate the planned 20:80, oxide:sulphide ratio planned for future years as well as maintain a consistent 75 um grind size. With the ball mill in conjunction with the extra CIL tank and oxygen plant, recoveries are expected to increase from 88% to 93%. As of September 2018, commissioning of the ball mill was complete and the additional CIL tank and oxygen plant remains on track for late-October 2018 and early-November 2018, respectively.

1.13Infrastructure

The site is connected to the national electrical grid by a 69 kilovolt (kV), 20 megavolt-ampere (MVA) power line via Companhia de Eletricidade do Amapá (CEA), the local supply authority. Power is also provided by an independent 11 MW continuous rated Aggreko diesel-powered generation system. Water is provided from recycled process water and water storage dams. The mine currently employs a total of 1,116 persons, of whom 416 are Beadell Brasil employees and 700 contractors. Approximately 99% are Brazilian nationals with the majority of the workforce from local towns in proximity to the mine. Accommodations for senior and junior staff members are provided by a camp located 2 km from the plant which is capable of housing 122 persons. The plant contains the mechanical treatment (crusher, mill and thickener) and chemical process (CIL, detox, oxygen plant, elution) areas. The other major infrastructure buildings include the reagents storage warehouse, reagents preparation plant, chemical laboratory and process laboratory, tailings dam and power distribution system. The main administration area includes maintenance (electrical and mechanical) workshops, mine administration facilities, technical services offices, stores warehouse, core yard, mess facility, and medical centre.

amcconsultants.com

x

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

1.14Market studies and contracts

Gold output from Tucano is in the form of doré bars which are shipped to Sao Paulo for refining by Umicore, the contract refiner. A number of operational duties have been contracted out to suppliers, most notably U&M is the principal mining contractors. SGS Geosol operates the offsite certified laboratory in Belo Horizonte, Minas Gerais and McKay operates a Schramm RC rig for grade control and resource drilling. The various contracts were awarded following a competitive bidding process, prices are within the industry range and comparable to other operations in Brazil.

1.15Environmental and social

In 2011 SRK Consultores do Brasil Ltda produced an Environmental Control Plan (PCA) to present changes implemented to the project’s environmental controls as a condition for the renewal of the Operating Licence issued by the State Secretariat of Environment, Amapá (SEMA). This followed a period of care and maintenance from 2009 until BDR acquired the project in 2010. The PCA reviewed changes to the proposed process plant configuration (from heap leach to CIL) and ways of minimizing the environmental impact of the plant up-grade. The PCA also covered the environmental aspects of mining and plans to monitor and manage these as well as implementing various programs for the local community.

1.16Capital and operating costs

Major capital expenditures for 2018 will include US$16.4M for the process plant upgrade, US$2.7M for the tails storage facility, US$1.5M for the powerline upgrade, and US$0.7M for clearing and hydro seeding. Capitalized stripping or miscellaneous minor capital requirements have not been reported. In 2017 cash operating costs for Tucano was US$1,100/oz of gold sold, which includes all mining, treatment, inventory adjustments and site general, and administrative costs. It excludes depreciation, amortization, sustaining capital, and corporate general and administration costs.

1.17Conclusions

Tucano is a successfully operating gold mine that started commercial production by BDR in January 2011 following a period of care and maintenance by the former owners, New Gold (operating as Mineração Pedra Branca do Amapari (MPBA)). BDR added a CIL circuit to the existing heap leach plant and commissioned it in November 2012.

The operation is projected to continue until 2023 based on currently available open pit Mineral Reserves. The exploration database for Tucano is reliable for the purpose of resource estimation. The Mineral Resources and Mineral Reserves have been updated to 30 June 2018.

As from 2018, a total of 24.7 Mt of ore is planned to be mined at an overall strip ratio of 5.6 to 1. Grade control reconciliation has confirmed the Mineral Resources and Mineral Reserves as previously stated for Tucano. The results of this update to the Mineral Resource and Mineral Reserve evaluation confirm the continued economic viability of exploiting the Tucano Gold Deposit. The current open pit LOM production schedule 2018 to 2023 considers 23.3 Mt of ore at an average grade of 1.43 g/t Au containing a total of 1.07 Moz of Au. In 2017, Tucano produced 129,764 oz Au at an all-in sustaining cost (AISC) of US$1,180/oz. which includes all mining, treatment, general and administrative costs, sustaining capital, and royalties which are incurred at the mine site. The mine level AISC costs exclude depreciation, amortization, and corporate general and administrative costs.

amcconsultants.com

xi

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

1.18Recommendations

Near mine exploration and resource definition drilling on key targets within and near the Urucum pit is recommended. This could have the potential to add low strip, near surface ounces to the reserves for 2018. Continued regional exploration on the established ranked list of targets is recommended to discover and define significant new gold deposits outside the mine corridor. Regional exploration work will involve stream and soil geochemistry with follow up diamond and RC drilling for the advanced projects. Total budget for Near Mine Exploration, Resource Confirmation, and Regional Exploration in 2018 is US$6.0M. The proposed work includes 25,200 m of RC and 5,500 m of diamond core, 5,700 m of Rotary Air Blast (RAB) and Auger, and 9,290 soil samples.

 

 

amcconsultants.com

xii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Contents

 

1 Summary iii
  1.1 Project summary iii
  1.2 Location iii
  1.3 Ownership iii
  1.4 Geology iii
  1.5 Mineralization iv
  1.6 History iv
  1.7 Drilling and exploration iv
  1.8 Sample preparation and analysis iv
  1.9 Mineral Resources v
  1.10 Mineral Reserves vi
  1.11 Mining ix
    1.11.1 Underground mine economics ix
  1.12 Metallurgy and process plant x
  1.13 Infrastructure x
  1.14 Market studies and contracts xi
  1.15 Environmental and social xi
  1.16 Capital and operating costs xi
  1.17 Conclusions xi
  1.18 Recommendations xii
2 Introduction 29
  2.1 Terms of reference 30
  2.2 Purpose of report 30
  2.3 Sources of information 30
3 Reliance on other experts 32
4 Property description and location 33
  4.1 Location 33
  4.2 Property ownership 33
  4.3 Mineral tenure 34
  4.4 Royalties and agreements 38
  4.5 Environmental liabilities 39
  4.6 Permits and other 39
5 Accessibility, climate, local resources, etc. 40
  5.1 Accessibility 40
  5.2 Physiography 40
  5.3 Climate 40
  5.4 Infrastructure 41
    5.4.1 Water 42
    5.4.2 Power 42
    5.4.3 Workforce 42
    5.4.4 Commercial resources and services 42
    5.4.5 Transportation 42
6 History 43
7 Geological setting and mineralization 44
  7.1 Regional geology 44
  7.2 Property geology 45
  7.3 Local geology and mineralization 48
    7.3.1 Tap AB and Urucum 49

 

amcconsultants.com

xiii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

    7.3.2 Urucum East 51
    7.3.3 Duckhead 51
  7.4 Mineralization weathering types 51
    7.4.1 Primary or sulphide mineralization 51
      7.4.1.1 Saprolite mineralization 51
    7.4.2 Colluvial mineralization 52
8 Deposit types 53
9 Exploration 54
  9.1 Airborne magnetics, radiometrics, and DEM 54
  9.2 Airborne electromagnetic survey 55
  9.3 Ground geophysics 56
  9.4 Petrophysics 57
  9.5 Geochemistry 57
  9.6 Geological mapping 59
10 Drilling 60
  10.1 Drilling methods 60
  10.2 Surveys and survey coordinate system 60
  10.3 Diamond drill core 60
  10.4 Recovery 61
  10.5 Drilling orientation 61
  10.6 Drillhole spacing 61
  10.7 Sampling 61
11 Sample preparation, analyses, and security 62
  11.1 Sample preparation 62
  11.2 Sample security 62
  11.3 Sample analysis 62
  11.4 Sample QAQC 62
  11.5 QAQC data analysis 62
  11.6 Statistical evaluation 63
  11.7 Onsite laboratory 63
    11.7.1 Tap AB grade control and resource dataset 63
    11.7.2 Tap C grade control and resource dataset 64
    11.7.3 Urucum grade control and resource dataset 65
  11.8 SGS Belo Horizonte laboratory 65
    11.8.1 Tap AB grade control and resource dataset 65
    11.8.2 Tap C grade control and resource dataset 66
    11.8.3 Urucum grade control and resource dataset 66
  11.9 QP conclusions 67
12 Data verification 69
13 Mineral processing and metallurgical testing 70
  13.1 Summary 70
  13.2 Test work review 71
  13.3 Ausenco FS metallurgical program 71
  13.4 BDR FS metallurgical program 71
  13.5 Testwork Process Development Ltd. 72
  13.6 SGS Geosol 72
  13.7 Conclusions and design criteria 73
    13.7.1 Ausenco and Ammtec FS program 73
    13.7.2 Beadell FS program 74
  13.8 Predicted recoveries 76

 

amcconsultants.com

xiv

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14 Mineral Resource estimates 77
  14.1 Data used 78
    14.1.1 Drillhole database 78
    14.1.2 Bulk density 80
  14.2 Interpretation and modelling 82
    14.2.1 Geological interpretation 82
      14.2.1.1 Tap AB and Urucum 82
      14.2.1.2 Tap C 84
      14.2.1.3 Duckhead 85
    14.2.2 Mineralization interpretation 86
      14.2.2.1 Tap AB and Urucum Open pit model 86
      14.2.2.2 Tap AB and Urucum Underground model 88
      14.2.2.3 Urucum North and South Underground model 90
      14.2.2.4 Urucum East model 91
      14.2.2.5 Tap C model 91
      14.2.2.6 Duckhead model 92
  14.3 Compositing 93
  14.4 Statistical analysis 94
    14.4.1 Tap AB Open Pit model 94
      14.4.1.1 Descriptive statistics 94
      14.4.1.2 High grade outlier analysis 95
      14.4.1.3 MIK cut-offs and indicator class statistics 95
    14.4.2 Urucum Open Pit model 96
      14.4.2.1 Descriptive statistics 96
      14.4.2.2 High grade outlier analysis 96
      14.4.2.3 MIK cut-offs and indicator class statistics 97
    14.4.3 Tap AB Underground model 98
      14.4.3.1 Descriptive statistics 98
      14.4.3.2 High grade outlier analysis 100
    14.4.4 Urucum North Underground model 100
      14.4.4.1 Descriptive statistics and top cuts 100
    14.4.5 Urucum South Underground model 102
      14.4.5.1 Descriptive statistics 102
    14.4.6 Urucum East model 105
      14.4.6.1 Urucum East summary statistics 105
    14.4.7 Tap C (Other) model 105
      14.4.7.1 Raw sample data 105
      14.4.7.2 2 m composite data 106
      14.4.7.3 Treatment of high grade gold values (g/t) 106
    14.4.8 Tap C (C3W and C3N) model 107
    14.4.9 Duckhead model 107
      14.4.9.1 Raw sample data 107
      14.4.9.2 2 m composite data 108
      14.4.9.3 Top cuts 109
  14.5 Variography 110
    14.5.1 Introduction 110
    14.5.2 Tap AB Open Pit model variography 110
    14.5.3 Urucum Open Pit model variography 111
    14.5.4 Tap AB Underground model variography 111
    14.5.5 Urucum North Underground model variography 111
    14.5.6 Urucum South Underground model variography 111
    14.5.7 Urucum East model variography 111
    14.5.8 Tap C (other) model variography 111

 

 

amcconsultants.com

xv

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

    14.5.9 Tap C (C3N and C3W) model variography 112
    14.5.10 Duckhead model variography 112
  14.6 Block modelling 113
    14.6.1 Tap AB and Urucum Open Pit block models 113
    14.6.2 Tap AB and Urucum Underground block models 113
    14.6.3 Urucum East, Tap C, and Duckhead block models 114
  14.7 Grade estimation 115
    14.7.1 Tap AB and Urucum Open Pit block models 115
      14.7.1.1 Introduction 115
      14.7.1.2 The MIK method 115
      14.7.1.3 Post MIK processing - E-type estimates 115
      14.7.1.4 Support correction (selective mining unit estimation) 117
      14.7.1.5 Indirect lognormal correction 117
      14.7.1.6 MIK and OK parameters 118
      14.7.1.7 Change of support 120
    14.7.2 Tap AB Underground - OK estimation 121
      14.7.2.1 Estimate validation 124
    14.7.3 Urucum North Underground OK estimation 124
      14.7.3.1 Urucum North Underground model - estimate validation 125
    14.7.4 Urucum South Underground model - OK estimation 125
      14.7.4.1 Urucum South Underground model - estimate validation 128
    14.7.5 Urucum East model-OK estimation 128
      14.7.5.1 Estimate validation 128
    14.7.6 Tap C (other) estimation 128
      14.7.6.1 Estimate validation 129
    14.7.7 Tap C Model (Tap C3N and Tap C3W areas) 131
    14.7.8 Stockpile estimation 131
    14.7.9 Duckhead estimation 132
  14.8 Depletion for mining activity 134
  14.9 Resource classification 134
  14.10 Resource reporting 136
  14.11 Comparison with previous estimates 138
15 Mineral Reserve estimates 142
  15.1 Summary 142
  15.2 Open pit 144
    15.2.1 Reserve block model 144
    15.2.2 Open pit optimization 145
    15.2.3 Dilution and extraction 145
    15.2.4 Gold grade data 145
    15.2.5 Cost parameters for pit optimization 145
    15.2.6 Pit optimization mill recovery 146
    15.2.7 Tap AB optimization results 146
    15.2.8 Urucum optimization results 147
    15.2.9 Open pit COG - Pit optimization and Reserves 148
  15.3 Underground mining 151
    15.3.1 Underground mine Mineral Reserve estimate 151
    15.3.2 Orebody geometry 151
    15.3.3 Cut-off grade (COG) 152
    15.3.4 Dilution and mining recovery estimates 152
    15.3.5 Mining method criteria and modifying factors 153
  15.4 Combined Mineral Reserve estimate 153
  15.5 Factors that may impact Mineral Reserve estimates 156

 

 

 

amcconsultants.com

xvi

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16 Mining methods 157
  16.1 Open pit mining 157
  16.2 Geotechnical assumptions 157
    16.2.1 Overall pit slopes 157
      16.2.1.1 Urucum 158
      16.2.1.2 Urucum East 158
      16.2.1.3 Tap AB 158
      16.2.1.4 Pegmatite 159
      16.2.1.5 Proposed overall slope angles 159
    16.2.2 Engineered pit designs 160
      16.2.2.1 Tap AB 160
      16.2.2.2 Urucum 162
      16.2.2.3 Urucum East 163
      16.2.2.4 Tap C 164
  16.3 Contract mining 165
    16.3.1 Grade control and dig plans 166
  16.4 Underground mining 167
    16.4.1 Geotechnical and hydrogeological considerations 167
    16.4.2 Data used 167
    16.4.3 Major structures 168
    16.4.4 In-situ stress environment 169
    16.4.5 Weathering 169
    16.4.6 Ground water 170
    16.4.7 Rock mass classification 170
    16.4.8 Stable stope dimensions 171
    16.4.9 Pillar dimensions 172
      16.4.9.1 Crown pillar 172
      16.4.9.2 Sill pillars 173
      16.4.9.3 Rib pillars 173
    16.4.10 Excavation and support requirement 173
      16.4.10.1 Lateral development 173
      16.4.10.2 Vertical development (ventilation shafts) 174
      16.4.10.3 Portal locations 174
    16.4.11 Underground mine design basis 174
      16.4.11.1 Mining limits 174
      16.4.11.2 Mineral Resource estimate 174
      16.4.11.3 Stope optimization 174
      16.4.11.4 MSO estimates 175
    16.4.12 Access development 177
      16.4.12.1 Decline stand-off distance 177
      16.4.12.2 Capital development estimates 178
      16.4.12.3 Operating development estimates 178
    16.4.13 Mining methods 178
    16.4.14 Up-hole retreat mining method 179
    16.4.15 Down-hole benching mining method 180
    16.4.16 Sill pillar recovery 181
    16.4.17 Ventilation strategy 182
      16.4.17.1 Level ventilation 183
      16.4.17.2 Development ventilation 184
    16.4.18 Ventsim modelling 185
      16.4.18.1 Modelling results 185
    16.4.19 Egress   185
    16.4.20 Underground mine production and development schedules 185

amcconsultants.com

xvii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

      16.4.20.1 Development profiles and scheduling rates 186
    16.4.21 LOM underground production schedule 186
    16.4.22 Underground mobile equipment 189
      16.4.22.1 Development drills / jumbos 190
      16.4.22.2 Production drills 190
      16.4.22.3 Underground trucks 191
      16.4.22.4 LHDs 192
      16.4.22.5 Ground support rigs 193
      16.4.22.6 Utility vehicles 193
    16.4.23 Underground mine personnel 193
      16.4.23.1 Working shifts 193
      16.4.23.2 Rosters 194
  16.5 Underground infrastructure 195
    16.5.1 Underground access 195
    16.5.2 Surface ventilation fans 196
    16.5.3 Change rooms and lamp room 196
    16.5.4 Underground mine offices 196
    16.5.5 Surface workshop 196
    16.5.6 Mines rescue centre 197
    16.5.7 Mine portal 197
    16.5.8 Water supply 197
    16.5.9 Existing facilities 197
    16.5.10 Power supply and distribution 197
    16.5.11 Water supply and distribution 198
    16.5.12 Dewatering 198
      16.5.12.1 Pump selection 198
      16.5.12.2 Sump design 198
      16.5.12.3 Dewatering system 199
    16.5.13 Compressed air 199
    16.5.14 Emergency egress 200
    16.5.15 Refuge chambers 200
    16.5.16 Underground communications 201
    16.5.17 Future data management systems 201
    16.5.18 Underground service bay 202
17 Recovery methods 203
  17.1 Summary 203
  17.2 Crushing and ore stockpiling 203
  17.3 Milling and classification 203
  17.4 CIL 203
  17.5 Tailings 204
  17.6 Elution 204
  17.7 Carbon regeneration 204
  17.8 Electrowinning and gold recovery 205
18 Project infrastructure 206
  18.1 Context and regional infrastructure 206
  18.2 Site access and logistics 207
  18.3 Mining and support facilities 207
  18.4 Sub-contractor facilities 208
  18.5 Process plant 209
  18.6 Water 209
    18.6.1 Raw water 209
    18.6.2 Potable water 209

amcconsultants.com

xviii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

    18.6.3 Process water 209
  18.7 Power 210
  18.8 Fire protection 210
  18.9 Communications 210
  18.10 Security 211
  18.11 Personnel and personnel logistics 211
  18.12 Accommodation and medical care 211
  18.13 Tailings Storage Facility (TSF) 211
    18.13.1 Tailings operation 211
    18.13.2 Description of the constructed TSFs 212
      18.13.2.1 Tap D TSF 212
      18.13.2.2 North Mill Pond TSF 214
      18.13.2.3 WPP1 TSF 216
      18.13.2.4 Integrated WPP1 and NMP TSFs 217
    18.13.3 Extended tailings storage capacity 218
      18.13.3.1 Barragem Leste TSF 220
      18.13.3.2 WPP2 TSF 222
    18.13.4 Permitting of the TSFs 223
    18.13.5 Conclusions   223
  18.14 Underground infrastructure 223
19 Market studies and contracts 224
  19.1 Markets 224
  19.2 Contracts 224
20 Environmental studies, permitting, and social or community impact 225
  20.1 Site visit 225
    20.1.1 Groundwater and surface water monitoring field check 225
    20.1.2 Socio-economics aspects field check 226
  20.2 Known environmental liabilities 226
  20.3 Biological resources (Fauna and Flora) 226
    20.3.1 Flora 227
    20.3.2 Fauna 227
    20.3.3 Threatened and special status species 228
  20.4 Air quality 228
  20.5 Noise quality and vibrations 229
  20.6 Geotechnical 229
  20.7 Hydrogeology (groundwater), hydrology (surface water) 229
  20.8 Cultural and archaeological resources 230
    20.8.1 Regional archaeological context 230
    20.8.2 Archaeological studies at Tucano Project 230
  20.9 Socio-economics 231
21 Capital and operating costs 233
  21.1 Capital expenditures 233
  21.2 Operating costs 233
    21.2.1 Underground capital costs - basis of estimate 233
    21.2.2 Contractor mining versus owner mining 233
    21.2.3 Total underground capital cost estimate 234
    21.2.4 Underground lateral development capital costs 236
    21.2.5 Underground vertical development capital costs 236
    21.2.6 Underground mobile equipment capital costs 236
    21.2.7 Underground infrastructure capital costs 236
    21.2.8 Surface infrastructure capital costs 237
    21.2.9 Exclusions from the underground cost estimate 237

amcconsultants.com

xix

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

    21.2.10 Indirect capital costs 237
    21.2.11 Capital contingency 237
    21.2.12 Underground operating costs - basis of estimate 238
    21.2.13 Underground mine total operating costs 238
    21.2.13.1        Underground mining cost 239
    21.2.14 Underground mobile equipment assumptions and costs 240
    21.2.15 Employee costs / labour costs 240
22 Economic analysis 242
  22.1 Underground mine economics 242
    22.1.1 Assumptions 242
    22.1.2 Economic analysis 242
  22.2 Taxes and Royalties 245
  22.3 Economic sensitivity analysis 246
23 Adjacent properties 249
24 Other relevant data and information 250
25 Interpretation and conclusions 251
    25.1 Risk assessment 251
    25.2 Mineral Resources and Mineral Reserves 251
    25.3 Mining 251
    25.4 Processing 251
    25.5 Production and all-in sustaining costs 252
    25.6 Health and safety 252
    25.7 Underground mining 252
26 Recommendations 254
  26.1 Operations 254
  26.2 Exploration and Resource Delineation 254
    26.2.1 Near mine and resource definition 254
    26.2.2 Regional exploration 254
  26.3 Underground mining 255
27 References 257
28 QP Certificates 258

 

Tables    
Table 1.1 Summary of Mineral Resources as of 30 June 2017 v
Table 1.2 Mineral Reserve key modifying parameters vi
Table 1.3 Tucano gold operation - Mineral Reserves as of 30 June 2017 vii
Table 2.1 Persons who prepared or contributed to this Technical Report 30
Table 4.1 GPR Mineral Tenure 35
Table 5.1 Monthly rainfall at Tucano from 2008 to 2016 inclusive 41
Table 7.1 Stratigraphic column (from AMC 2009) 46
Table 7.2 Description of mineralized zones in each deposit 49
Table 9.1 Conductivity test results of a sample of pyrrhotite rich core from Urucum 57
Table 9.2 Number of exploration samples collected by sample type and company 58
Table 13.1 SGS Geosol samples 72
Table 13.2 SGS Geosol bottle roll results 73
Table 13.3 Selected design criteria (Ausenco) 74

 

 

amcconsultants.com

xx

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.1 Summary of estimated Mineral Resources (as of 30 June 2017) 78
Table 14.2 Drillhole data used in the Open Pit Mineral Resource estimates 79
Table 14.3 Summary of bulk density measurements by weathering type 81
Table 14.4 Urucum: Comparative statistics of bulk density 81
Table 14.5 Tap AB: Comparative statistics of bulk density 81
Table 14.6 Tap C: Comparative statistics of bulk density 81
Table 14.7 Duckhead: Comparative statistics of bulk density 82
Table 14.8 Tap AB Gold Deposit - Open Pit model summary statistics gold (g/t) 94
Table 14.9 Tap AB Gold Deposit - Open Pit Resource indicator class statistics 96
Table 14.10 Urucum Gold Deposit - Open Pit model; summary statistics gold (g/t) 97
Table 14.11 Urucum Gold Deposit - Open Pit model indicator class statistics (selective) 98
Table 14.12 Tap AB Underground model; statistics by domain 99
Table 14.13 Tap AB Underground Resource; 3 m composite top cut capping by domain 100
Table 14.14 Urucum North Underground Resource statistics; raw, composited, and capped 101
Table 14.15 Urucum South Underground Resource statistics; Au (g/t) 102
Table 14.16 Urucum South Underground Resource statistics; raw gold data (g/t) 104
Table 14.17 Urucum East 1 m composites by domain - summary statistics 105
Table 14.18 Raw data statistic summary - grouped ore domains gold (ppm) 105
Table 14.19 Tap C and gap, 2 m composite statistical summary of variogram sector VERT 106
Table 14.20 Tap C (other) model; top grade for 2 m composite - Au (g/t) 106
Table 14.21 Tap C3W and C3N 2 m composites by domain - summary statistics 107
Table 14.22 Tap C3W and C3N 2 m applied top cuts by domain 107
Table 14.23 Duckhead; raw data Au (g/t), statistical summary by domain 108
Table 14.24 Duckhead; 2 m composite statistical summary - grouped by ore lode 109
Table 14.25 Duckhead determined top cuts for each lode 110
Table 14.26 Tap AB Gold Deposit - Open Pit Resource block model parameters 113
Table 14.27 Urucum Gold Deposit - Open Pit Resource block model parameters 113
Table 14.28 Tap AB Underground block model parameters 114
Table 14.29 Urucum North Underground block model parameters 114
Table 14.30 Urucum South Underground block model parameters 114
Table 14.31 Urucum East Gold Deposit block model parameters 114
Table 14.32 Tap C Gold Deposit block model parameters 115
Table 14.33 Duckhead Gold Deposit block model parameters 115
Table 14.34 Tap AB and Urucum open pit block model Indicator cut-off and probability 116
Table 14.35 Tap AB Gold Deposit - Open Pit Resource MIK sample search criteria 119
Table 14.36 Urucum Gold Deposit - Open Pit Resource MIK sample search criteria 119
Table 14.37 Tap AB Gold Deposit - Open Pit Resource OK sample search criteria 120
Table 14.38 Urucum Gold Deposit - Open Pit Resource OK sample search criteria 120
Table 14.39 Variance adjustment ratios (3 mE x 5 mN x 4 mRL SMU) 121
Table 14.40 Tap AB Gold Deposit - Underground Resource; orientation and radius of search radius of individual lodes / oxide domains 122

 

 

 

amcconsultants.com

xxi

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

Table 14.41 Urucum South Underground model: orientation of search radius of individual lodes 126
Table 14.42 Urucum East summary estimation parameters 128
Table 14.43 Statistical validation of Au (g/t) of 1st neighbourhood 130
Table 14.44 Estimation parameters for Tap C (Tap C3N and Tap C3W areas) 131
Table 14.45 Duckhead search ellipses by lode / oxidation domain 133
Table 14.46 Resource classification criteria 135
Table 14.47 Tucano Gold Resources 30 June 2017 137
Table 14.48 Mineral Resource changes by deposit and physical reporting limits 139
Table 14.49 Comparison of Mineral Resource estimates 141
Table 15.1 Proportion of reserves by deposit 144
Table 15.2 Optimization cost parameters 146
Table 15.3 COG estimation parameters using pit shell optimization gold price 149
Table 15.4 COG estimation parameters using the US$1,200 gold price 150
Table 15.5 Urucum North Underground Mineral Reserve estimate 151
Table 15.6 Total Mineral Reserves - 30 June 2017 154
Table 16.1 Recommended wall design parameters 157
Table 16.2 Measured overall slope angles (degrees) 158
Table 16.3 Proposed overall slope angles (degrees) 160
Table 16.4 Urucum pits design data 163
Table 16.5 Tucano mining fleet 166
Table 16.6 Grade control grade ranges by material type 167
Table 16.7 Diamond drillholes used in the geotechnical analysis 168
Table 16.8 Range of Q’ and RMR values 171
Table 16.9 Stope design factors and hydraulic radii 171
Table 16.10 Urucum North Underground Mineral Resource estimate - based on COG of 1.6 g/t Au 174
Table 16.11 MSO parameters 176
Table 16.12 Lateral capital development estimates 178
Table 16.13 Vertical capital development estimates 178
Table 16.14 Operating lateral development estimates 178
Table 16.15 Surface fan details 185
Table 16.16 Lateral development details 186
Table 16.17 Vertical development details 186
Table 16.18 LOM underground production schedule 188
Table 16.19 Major equipment required over LOM 189
Table 16.20 Underground workforce time allocation during shift 194
Table 16.21 Mining department employees - excluding UG equipment operators and maintenance personnel 195
Table 18.1 Summary of TSF storage capacity 212
Table 21.1 Cash operating costs 2017 233
Table 21.2 Pre-production capital and total capital cost estimate 234
Table 21.3 Capital cost estimate by year 235

 

 

amcconsultants.com

xxii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

Table 21.4 Annual capital expenditure 235
Table 21.5 Underground infrastructure capital costs 236
Table 21.6 Surface infrastructure capital costs 237
Table 21.7 Capital contingency 238
Table 21.8 LOM underground total operating costs by major area 238
Table 21.9 LOM underground total operating costs by year 239
Table 21.10 LOM average underground total operating costs 239
Table 21.11 Underground mining costs 239
Table 21.12 Underground mobile equipment productivity assumptions 240
Table 21.13 Mobile equipment operating cost assumptions 240
Table 21.14 Mobile equipment maintenance cost assumptions 240
Table 21.15 Employee wages 241
Table 21.16 Employee benefits 241
Table 22.1 Key economic assumptions and results for the underground mine 243
Table 22.2 Urucum North Underground LOM production and cash flow forecast 244
Table 22.3 Economic sensitivity analysis (pre-tax) 247
Table 26.1 2018, Resource Definition, Near mine, and regional exploration budget 255
Figures    
Figure 4.1 Tucano mine location map 33
Figure 4.2 GPR tenement ownership map with tenement status 37
Figure 5.1 Monthly rainfall at Tucano from 2008 to 2016 inclusive 41
Figure 7.1 Geology map of basement geology overlain by the Property tenements 44
Figure 7.2 Property geology map 47
Figure 7.3 Tucano deposit location map 48
Figure 7.4 Tap AB Gold Deposit section 94,550 mN 50
Figure 8.1 Reconstruction of the Guiana Craton and West Africa Shield 53
Figure 9.1 Merged Airborne Magnetic Total Magnetic Image (AS) 55
Figure 9.2 SPETREM electromagnetic image 56
Figure 9.3 Photo of the conductivity test sample 57
Figure 9.4 Tenement status map showing the coverage of soil sampling 58
Figure 9.5 Serra da Canga East stream sediment anomaly 59
Figure 11.1 Control chart for standard GE076 64
Figure 11.2 Control chart for Standard G311-5 67
Figure 13.1 Proposed Tucano expansion flow sheet 75
Figure 14.1 Plan view of drilling Urucum (left) and Tap AB (right) 80
Figure 14.2 Urucum Gold Deposit cross section displaying geology and coded block model 83
Figure 14.3 Tap AB Gold Deposit cross section displaying geology and coded block model 84
Figure 14.4 Isometric view of Tap C lithology solids 85
Figure 14.5 Plan view of Duckhead showing the modelled lithological units 86
Figure 14.6 Tap AB Gold Deposit isometric SE view 87
Figure 14.7 Urucum Gold Deposit isometric SE view 88
Figure 14.8 Oblique view of the Tap AB constructed mineralization wireframes 89

 

 

amcconsultants.com

xxiii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

Figure 14.9 Cross section of all Urucum North Underground domains 90
Figure 14.10 Long section view of Urucum showing the underground mineralization domains 91
Figure 14.11 Tap C gold mineralization domains - oblique view 92
Figure 14.12 Mineralized wireframes of Duckhead and surrounding deposits 93
Figure 14.13 Urucum East Model - resource classification - HG Lode 136
Figure 15.1 Deposit location plan 143
Figure 15.2 Tap AB optimization results 147
Figure 15.3 Urucum optimization results 148
Figure 16.1 Tap AB1/2 final design 161
Figure 16.2 Tap AB3 final design 162
Figure 16.3 Urucum final design 163
Figure 16.4 Urucum East final design 164
Figure 16.5 Tap C final design 165
Figure 16.6 Long projection of Urucum North Underground looking west, showing geotechnical drillhole locations 168
Figure 16.7 Cross-section showing weathering profile (Section 99,865 mN) 170
Figure 16.8 Modified Mathews short-term stability estimate 172
Figure 16.9 Tonnage / grade curves based on MSO stope shapes generated above 1.6 g/t Au COG 175
Figure 16.10 3D view of mine design and MSO stopes - by lode number 177
Figure 16.11 Long projection indicating up-hole retreat mining sequence 179
Figure 16.12 Long projection indicating down-hole benching mining method and sequence 180
Figure 16.13 Sill pillars 181
Figure 16.14 Options for sill pillar recovery 182
Figure 16.15 Long projection of the primary ventilation system 183
Figure 16.16 Forced ventilation for a typical level 184
Figure 16.17 Projected production profile 187
Figure 16.18 Major equipment required over LOM 189
Figure 16.19 Simba H1354 production drill 191
Figure 16.20 Scania P420 truck being loaded by a Volvo front-end loader 192
Figure 16.21 Section of proposed sump layout 199
Figure 16.22 MineArc refuge chambers 201
Figure 18.1 U&M workshop facilities 208
Figure 18.2 Tap D embankments 213
Figure 18.3 Typical wall cross section 214
Figure 18.4 NMP embankments 215
Figure 18.5 WPP1 embankments 216
Figure 18.6 Wall 11 cross section 217
Figure 18.7 Integrated WPP1 and NMP TSFs 218
Figure 18.8 Proposed TSF expansion 219
Figure 18.9 Typical cross section of Walls 21 and 22a 221
Figure 18.10 WP TSF layout 222
Figure 20.1 Location map of field visit monitoring points 226

 

 

amcconsultants.com

xxiv

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

Figure 22.1 Production costs, revenues, and cumulative pre-tax cash flow by year 245
Figure 22.2 Sensitivity analysis - pre-tax NPV at 5% discount rate 247
Figure 22.3 Pre-tax NPV and IRR sensitivities to changes in the gold price 248
Figure 23.1 Tenement ownership map 249

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution list

1 e-copy to Great Panther Silver Limited

1 e-copy to AMC Vancouver office

 

amcconsultants.com

xxv

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

Acronyms and abbreviations

  Description   Description
$ United States of America dollars M million
µm micrometre m metres
2D two dimensional m3 cubic metre
3D three dimensional m3/h cubic metre per hour
AAS atomic absorption spectrometer m3/s cubic metre per second
AEM airborne electromagnetic Ma Million years
AISC all-in sustaining cost MACA Mining and Civil Australia
ANM Agência Nacional de Mineração (National Mining Agency, Brazil) mbs metres below surface
ANQUIM Análise Química Mineral, Ambiental e Industrial Mineral mE metres east
ASX Australian Securities Exchange MII Measured + Indicated + Inferred
Au gold MIK Multiple Indicator Kriging
AWD all-wheel drive min minute
bcm bank cubic metres ml millilitre
BDR Beadell Resources Ltd mm millimetres
BIF Banded Iron Formations Mm3 Million cubic metres
BVI Blast Vector Indicators MMI mobile metal ion
ºC degrees centigrade mN metres north
CC correlation coefficient mRL metres reduced level
ccdf conditional cumulative distribution function Moz million ounces
CEA Centrais Elétricas do Amapá MPBA Mineração Pedra Branca do Amapari
CFEM Compensation for Exploitation of Mineral Resources MPC Mine Power Centres
cfm cubic feet per minute MPH MPH Minerals Consultancy Ltd.
CIC carbon in column MSO Mineable Shape Optimizer
CIL carbon-in-leach Mtpa million tonnes per annum
CIP carbon-in-pulp Mt Million tonnes
cm centimetre MVA megavolt-ampere
CO carbon monoxide MW megawatt
CO2 carbon dioxide N northing
COG cut-off grade NaCN sodium cyanide
CSLL Social Contribution Tax on Profits NATA National Association of Testing Authorities
CSS closed side setting NN Nearest Neighbour
cusum cumulative sum of the deviations NMP North Mill Pond
CV coefficient of variation NO nitric oxide
dBA decibels NO2 nitrogen dioxide
DDH diamond drillhole NPV net present value
FS Feasibility Study NQ2 size of diamond drill rod / bit / core
DEM Digital Elevation Model O2 oxygen

 

amcconsultants.com

xxvi

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

  Description   Description
DNPM Departamento Nacional de Produção Mineral (National Department of Mineral Production, Brazil) OK Ordinary Kriging
DTM digital terrain model oz troy ounce
E (X) easting P80 -75 µm 80% passing 75 microns
EBX EBX Gold Ltd PAL pulverize and leach
EDM electronic distance measuring PBX private branch exchange
EGL effective grinding length PCA Environmental Control Plan
EPCM engineering, procurement, and construction management PDC Power Distribution Centre
EPS Earth Works Production Scheduling PETN Penta Erythritol Tetra Nitrate
EV expected value PFS Pre-Feasibility Study
FIFO fly in fly out ppb parts per billion
g gram ppm parts per million
G&A General and Administration psi pounds per square inch
g/m³ grams per cubic metre PVC poly vinyl chloride
GPR Great Panther Silver Limited QC quality control
g/t grams per tonne QP Qualified Persons
ha hectare Q-Q quantile-quantile
HARD half the absolute relative difference R$ Brazilian Real
HCl hydrochloric acid RAB rotary air blast
HDPE high density poly ethylene RC reverse circulation
HQ2 size of diamond drill rod / bit / core RL (Z) reduced level
HR hydraulic radii ROM run-of-mine
hr hours RQD rock quality designation
HRD half relative difference RWC Ray Walton Consulting Inc.
ICP-MS inductivity coupled plasma mass spectroscopy SCS Southern Geoscience Consultants
ID Inverse Distance weighting SD standard deviation
ID² Inverse Distance Squared SEMA State Secretariat of Environment, Amapá
IP Induced Polarization SGS Société Générale de Surveillance
IPD Inverse Power Distance SMBS sodium metabisulfite
IPS integrated pressure stripping SMU selective mining unit
IRPJ Corporate Income Tax SO2 sulphur dioxide
IRR internal rate of return SSAG single-stage, semi-autogenous grinding
IRS Inter Ramp Slope SUDAM Superintendence of Amazonas Development
ISO International Standards Organization t tonnes
IT Integrated Tool carrier t/hr tonnes per hour
ITS Inchcape Testing Services t/m³ tonnes per cubic metre
kg kilogram TFRM Control, Monitoring and Supervision of Research Activities, Mining, Exploration and Exploitation of Mineral Resources Fee
kg/m3 kilogram per cubic metre TMI Total Magnetic Intensity
kg/t kilogram per tonne tpd tonnes per day

 

amcconsultants.com

xxvii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

  Description   Description
km kilometres TSF Tailings Storage Facility
km² square kilometres U&M Unienge & Modulo
kt kilotonne US$ United States of America dollars
ktpa thousand tonnes per annum UTE Thermoelectric Plant
kV kilovolt VLF Very Low Frequency
kW kilowatt vm vertical metre
kWh kilowatt hour VPN Virtual Private Network
LHD Load Haul Dump WPP1 West Pond Phase 1
LOM life of mine WPP2 West Pond Phase 2
l/hr/m² litres per hour per square metre    

 

 

 

 

amcconsultants.com

xxviii

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

2Introduction

This report has been prepared for Great Panther Silver Limited (GPR) in connection with the proposed acquisition (the Acquisition) by GPR of Beadell Resources Limited (BDR) pursuant to a Scheme Implementation Deed entered into between GPR and BDR on 23 September 2018. GPR has announced the friendly acquisition of BDR. The all-shares transaction will result in the consolidation of the two companies in order to create an emerging intermediate gold producer. Subsequently, GPR is required to file a technical report on the Tucano Property (Property) in order to support its disclosure within the Information Circular (expected late November) for the meeting of the shareholders of GPR to be held to approve the Acquisition.

AMC Mining Consultants (Canada) Ltd. (AMC) was retained by GPR to prepare a Technical Report in accordance with National Instrument 43-101 “Standards of Disclosure for Mineral Projects” of the Canadian Securities Administrators (NI 43-101) for the Tucano Gold Mine and surrounding concessions (Property). The Property is located in Amapá State in northern Brazil. The nearest major populated centre to the Tucano site is Macapá, situated on the northern bank of the Amazon River.

Tucano Gold Mine is currently wholly owned by BDR and its Brazilian subsidiary, Beadell Brasil Ltda (Beadell Brasil). The Tucano Gold Mine is an operating mine that produced 129,764 oz’s of gold in 2017. Current operations are from Tap AB, Tap C, and Urucum deposits.

AMC is responsible for managing and preparing the Technical Report with inputs from the following Qualified Persons (QP): Mr G. Methven from AMC Mining Consultants (Canada) Ltd., Mr B. Wolfe from International Resource Solutions Pty Ltd., Mr N. Spicer from Minesure Pty Ltd., Mr R. Lacourt from LOM Consultants, Mr J. Moreno from SRK Consultants, Mr P. O’Bryan from Peter O’Bryan and Associates, Mr R. Walton from Ray Walton Consulting Inc., and Mr M. Batelochi from Soluções em Geologia e Mineração Ltda.

amcconsultants.com

29

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 2.1 Persons who prepared or contributed to this Technical Report

Qualified Persons responsible for the preparation of this Technical Report
Qualified Person Position Employer Independent of GPR Date of last site visit Professional designation Sections of report
Mr G. Methven Principal Mining Engineer AMC Mining Consultants (Canada) Ltd. Yes None P.Eng. (BC) 1 (part), 2, 3 (part), 15 (part), 16 (part), 19, 21, 22 (part), 24, 25 (part), 26 (part).
Mr B. Wolfe Principal Resource Geologist International Resource Solutions Pty Ltd Yes 3 Aug 2015 MAIG 1 (part), 4 (part), 5 (part) 6 - 12, 14 (part), 23, 25 (part), 26 (part), 27 (part).
Mr N. Spicer Principal Mining Engineer Minesure Pty Ltd Yes 8 Feb 2017 C.Eng. MIMMM 1 (part), 3 (part), 15 (part), 16 (part), 22 (part), 25 (part.
Mr R. Lacourt Principal Mining Engineer LOM Consultants Yes 4 April 2018 SME - RM Section 5 (part), 18 (part).
Mr J. Moreno Principal Geotechnical Engineer SRK Consultants Yes 21 Oct 2016 MIEAust CPEng. Section 18 (part).
Mr P. O'Bryan Principal Mining Engineer Peter O'Bryan and Associates Yes 2 June 2015 MAusIMM (CP) Section 16 (part).
Mr R. Walton Principal Engineer Ray Walton Consulting Inc Yes 15 Jan 2016 P.Eng. (Ontario) Section 13 (part), 17 (part), 25 (part).
Mr M. Batelochi Principal Resource Geologist Soluções em Geologia e Mineração Ltda Yes 20 March 2018 MAusIMM (CP) 1 (part), 4 (part), 14 (part), 20, 26 (part), 27 (part).
Other Experts who assisted the Qualified Persons
Expert Position Employer Independent of GPR Visited site Sections of report
Mr R. Rocha Civil Engineer SRK Consultants Yes 18 April 2018 Section 18.
Mr P. O'Bryan Principal Mining Engineer Peter O'Bryan and Associates Yes 2 June 2015 Section 15.
Mr L. Azevedo Partner FFA Legal Yes None Section 4.
Mr R. Lessa Attorney FFA Legal Yes None Section 4 and 22
2.1Terms of reference

Great Panther Silver Limited (GPR) entered into a Scheme Implementation Deed dated 23 September 2018, that will result in the acquisition of all of the issued ordinary shares of BDR. Upon completion of the transaction, the Tucano Project will be 100% owned and operated by GPR. GPR is a primary silver mining and exploration company listed on the Toronto Stock Exchange trading under the symbol GPR, and on the NYSE American under the symbol GPL. AMC has prepared this Technical Report for the Tucano Gold Property on behalf of GPR according to NI 43-101.

2.2Purpose of report

The purpose of this report is to restate GPR’s Mineral Resource and Mineral Reserve statement for the Tucano Gold Mine as of 30 June 2017. This Technical Report conforms to the standards set out in NI 43-101, pursuant to Form 43-101F.

2.3Sources of information

This report relies on historic and recent data generated by BDR and GPR. GPR has re-engaged a number of specialist consultants and information from these reports prepared by previous independent consultants has been utilized in the compilation of this report. A full listing of the principle sources of information are included in Section 27 of this report.

amcconsultants.com

30

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

This report has been prepared by AMC for GPR. The information, conclusions, opinions, and estimates contained herein, for which the named Qualified Persons (QPs) take responsibility, are based on:

Information available to AMC, at the time of preparation of this report.
Assumptions, conditions, and qualifications as set forth in this report.
Data, reports, and other information supplied by GPR and from other sources.

 

 

 

amcconsultants.com

31

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

3Reliance on other experts

The QPs have relied, in respect of legal and taxation aspects, upon the work of the Experts listed below. To the extent permitted under NI 43-101, the QPs disclaim responsibility for the relevant section of the Technical Report.

The following disclosure is made in respect of this expert:

Luis Mauricio Ferraiuoli de Azevedo, Partner FFA Legal.

Report, opinion, or statement relied upon:

Title Opinion on the Mineral Rights held by Beadell’s group dated 17 September 2018

Extent of reliance:

Full reliance following a review by the Qualified Person(s).

Portion of Technical Report to which disclaimer applies:

Section 4.3

The following disclosure is made in respect of this expert:

Rodrigo Simões Lessa, Attorney, FFA Legal.

Report, opinion, or statement relied upon:

Taxation and royalties

Extent of reliance:

Full reliance following a review by the Qualified Person(s).

Portion of Technical Report to which disclaimer applies:

Sections 4.4 and 22.1 for royalties and Section 22.2 for taxation

amcconsultants.com

32

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

4Property description and location
4.1Location

The Property is located at latitude 0.85°N and longitude 52.90°W in Amapá, the most north-eastern state of Brazil, approximately 15 km from the town of Serra do Navio and was formerly an open pit mining and heap leaching operation. It ran from late 2005 until January 2009, producing approximately 292,000 troy ounces (oz) of gold from 8.8 million tonnes (Mt) of ore. The property was acquired by BDR in 2010 and the plant upgraded with the addition of SAG mill and carbon-in-leach (CIL) infrastructure capable of treating sulphide ore. From November 2012 to 30 June 2017, 17.0 Mt at 1.34 g/t Au containing 735,294 oz Au was processed made up of a blend of pit oxide ore, sulphide ore, spent ore, and historic stockpiles. The mine is approximately 200 km from Macapá, the state capital, and is accessible by the Brazilian federal highway BR-210, or by chartered aircraft (Figure 4.1).

Figure 4.1 Tucano mine location map

Source: BDR

4.2Property ownership

The Property and the Tucano Gold Mine is currently wholly owned by BDR and its Brazilian subsidiary, Beadell Brasil Ltda (Beadell Brasil), which is to be acquired by GPR. The Tucano Gold Mine is an operating mine that produced 129,764 oz’s of gold in 2017. Current operations are from Tap AB, Tap C, and Urucum deposits. Upon completion of the Acquisition, existing BDR and GPR shareholders are expected to own approximately 38% and 62%, respectively, of the combined company.

 

amcconsultants.com

33

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

4.3Mineral tenure

GPR will hold tenements totalling approximately 2,500 km2. Details of each tenement including area and status is provided in Table 4.1.

Outside of the Mining Concession 851.676 / 1992, GPR holds a 2,500 km2 area of prospective exploration tenements at a grassroots level of exploration (Mining Concession is centred in the circle; Figure 23.1). This ground spans a length of 100 km of Paleoproterozoic greenstones and is 100% GPR owned with the exception of 4 tenements with Iron Ore concessions currently held by Zamin Ferrous (Zamin). Within Zamin’s leases, GPR has 100% gold rights whereas Zamin retains the iron ore rights - refer to Figure 7.2. In 2017 BDR reached an agreement with joint venture partner Mineração Vale dos. Reis Ltda (MVR) to convert its interest from 70% to 100%.

Table 4.1 includes all GPR's mineral rights (including tenement status), clarifying that all mineral rights are owned by GPR, but there are some tenements still held by Mineração Tanagra, Mineração Dorica and Mineração Vale doc Reis, which are current titleholders registered before the Brazilian National Mining Agency (Agência Nacional de Mineração (ANM)) that will replace current regulator National Department of Mineral Production (Departamento Nacional de Produção Mineral (DNPM)) as Table 4.1 shows. This means that the assignment of the tenements to BDR's Brazilian subsidiaries (Marina Norte and Serra da Canga) have already been requested before the ANM (replacing the DNPM) but have not been approved yet. In most of those cases, since the tenements are in exploration application phase, they can only be assigned after the ANM grants the respective exploration permits which has not happened yet.

In cases where there is already an exploration permit granted, GPR must pay TAH, which means Annual Fee per Hectare and shall be paid until January or July each year, depending on the date in which the exploration permit was published and is a fixed value per hectare, being R$3.21 during the original period of the exploration permit and R$4.86 during its extension period.

Figure 4.2 shows a map of these tenements as they relate to the mining concession shown in red. The peripheral tenements are treated as part of the property as any discovery would be treated in a central processing facility.

amcconsultants.com

34

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 4.1 GPR Mineral Tenure

Process Titleholder Status Area (ha) Project Phase License number Publication date Renewal date Expiration date Tah / June 2018 Substance District
858.046/09 Beadell Brasil Ltda In progress 1,445.09 Tucano

Exploration license

extended

14,660 29 Apr 2015   27 Apr 2018   Gold

Pedra Branca do Amapari e Porto

Grande

858.017/04 Beadell Brasil Ltda In progress 2,527.46 Tucano

Exploration license

extended

9,436 29 Apr 2015   27 Apr 2018   Manganese Porto Grande
850.852/87 Mineração Vale dos Reis Ltda Total assignment submitted 3,453.00 Tucano

Exploration license

extended

14,658 29 Apr 2015   27 Apr 2018   Molybdenum Amapá e Macapá
858.044/09 Mneração Serra da Canga Ltda Total assignment submitted 2,249.40 Tucano

Exploration license

extended

14,557 29 Apr 2015   27 Apr 2018   Gold

Pedra Branca do Amapari e Porto

Grande

854.262/93 Mineração Tanagra Ltda Total assignment submitted 9,793.10 Tucano

Exploration license

extended

4,120 15 Jan 2016   15 Jan 2019 R$47,594.47 Gold Macapá
858.080/14 Beadell Brasil Ltda In progress 4,593.14 Tucano Exploration license 11056 6 Oct 2016 5 Jul 2019 4 Sep 2019   Gold Serra do Navio e Pedra Bca Amapari
858.002/16 Beadell Resources Mineração Ltda In progress 9,408.23 Tartarugalzinho Exploration license 11,060 6 Oct 2016 5 Jul 2019 4 Sep 2019   Gold Tartarugalzinho
858.001/16 Mneração Serra Da Canga Ltda In progress 543.03 Tucano Exploration license 11,059 6 Oct 2016 5 Jul 2019 4 Sep 2019   Gold Serra do Navio e Pedra Bca Amapari
858.091/13 Beadell Brasil Ltda In progress 4,469.33 Tucano Exploration license 11,279 17 Oct 2016 16 Jul 2019 17 Sep 2019   Gold Serra do navio e pedra bca amapari
858.098/14 Beadell Resources Mineração Ltda Pending appeal 8,006.31 Tucano Exploration license 11,281 17 Oct 2016 16 Jul 2019 17 Sep 2019   Gold

Pedra Branca do Amapari e Porto

Grande

858.078/09 Mneração Serra da Canga Ltda In progress 9,823.41 Tucano

Exploration license

extended

663 18 Apr 2017   17 Mar 2020 R$47,741.77 Gold

Serra do Navio e Pedra Branca do

Amapari

858.124/13 Beadell Resources Mineração Ltda In progress 5,813.46 Tucano

Exploration license

extended

3,140 14 Aug 2017   14 Jul 2020   Gold

Pedra Branca do Amapari E Porto

Grande

858.010/10 Mineração Vale DOS Reis Ltda In progress 289.94 Tucano

Exploration license

extended

290 30 Aug 2017   28 Jul 2020   Gold

Pedra Branca do Amapari e Porto

Grande

858.076/09 Mneração Serra da Canga Ltda In progress 8,807.03 Tucano

Exploration license

extended

14,559 17 Jan 2018   17 Dec 2020 R$42,802.17 Gold Serra do Navio
858.022/14 Beadell Resources Mineração Ltda In progress 9,348.46 Tucano Exploration license 363 18 Jan 2018 18 Oct 2020 18 Dec 2020 R$30,008.56 Gold Porto Grande
858.007/18 Beadell Resources Mineração Ltda In progress 9,992.91 Tucano

Application for

exploration

      N/A   Gold Ferreira Gomes e Porto Grande
858.008/18 Beadell Resources Mineração Ltda In progress 6,002.44 Tucano

Application for

exploration

      N/A   Gold Serra do Navio / Pedra Branca do Amarapari
858.100/14 Beadell Brasil Ltda In progress 1,376.59 Tucano

Application for

exploration

      N/A   Gold

Serra do Navio e Pedra Bca

Amapari

858.103/11 Beadell Brasil Ltda Pending appeal 5,530.25 Tucano

Application for

exploration

      N/A   Iron Pedra Branca do Amapari
858.099/14 Beadell Resources Mineração Ltda Pending appeal 9,999.78 Tucano

Application for

exploration

      N/A   Gold

Pedra Branca do Amapari e Porto

Grande

858.081/14 Beadell Resources Mineração Ltda In progress 4,874,53 Tucano

Application for

exploration

      N/A   Gold Porto Grande
855.033/94

Marina Norte Empreendimentos

de Mineraação S.A

In progress 3,262.30 Tucano

Application for

exploration

      N/A   Gold Ferreira Gomes
851.766/94 Mineração Dorica Ltda

Total assignment

submitted

/ pending appeal

8,982.86 Tucano

Application for

exploration

      N/A   Gold Serra do Navio
851.770/94 Mineração Dorica Ltda   4,746.61 Tucano

Application for

exploration

      N/A   Gold Serra do Navio
851.771/94 MINERAÇÃO DORICA LTDA Pending appeal 8,750.06 Tucano

Application for

exploration

      N/A   Gold Serra do Navio e Pedra Bca Amapari
858.062/95 Mineração Tanagra Ltda In progress 8,982.41 Tucano

Application for

exploration

      N/A   Gold Macapá
858.082/17 Beadell Resources Mineração Ltda In progress 1,038.31 Tucano

Application for

exploration

      N/A   Gold Pedra Branca do Amapari

 

amcconsultants.com

35

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Process Titleholder Status Area (ha) Project Phase License number Publication date Renewal date Expiration date Tah / June 2018 Substance District
858.079/17 Beadell Resources Mineração Ltda In progress 268.94 Tucano

Application for

exploration

      N/A   Gold Porto Grande
858.095/17 Beadell Resources Mineração Ltda In progress 643.77  

Application for

exploration

      N/A   Gold Porto Grande
858.099/17 Beadell Resources Mineração Ltda In progress 996.82  

Application for

exploration

      N/A   Gold Porto Grande
858.050/95 Mineração Tanagra Ltda

Total assignment

submitted / Faixa de

Fronteira (Brazilian border

zone)

9,300.09 Tucano

Application for

exploration

      N/A   Gold Macapá
858.051/95 Mineração Tanagra Ltda

Total assignment

submitted / Faixa de

Fronteira (Brazilian border

zone)

6,371.28 Tucano

Application for

exploration

      N/A   Gold Macapá
858.079/14 Beadell Brasil Ltda Leasehold partial 150.08 Duckhead Partial lease       N/A   Gold Pedra Branca do Amapari
858.010/99 Beadell Brasil Ltda Pending appeal 8,634.00 Tucano Bid       N/A     Pedra Branca do Amapari
850.865/87 Mneração Serra da Canga Ltda In progress 6,111.83 Tucano

Exploitation

application

6,389 24 Mar 2017   N/A   Gold & iron

Pedra Branca do Amapari e Porto

Grande

851.439/80 Beadell Resources Mineração Ltda Final report submitted 9,601.89 Tartarugalzinho

Exploitation

application

3,162 10 May 2016   N/A   Gold Tartarugalzinho
858.000/98 Beadell Brasil Ltda Positive final report submitted 7,884.08 Tucano

Final report

presented

2,949 5 May 2006   N/A   Gold & aluminum Ferreira Gomes e Porto Grande
858.263/96 Beadell Brasil Ltda Positive final report submitted 9,690.63 Tucano

Final report

presented

1,578 5 May 2006   N/A   Gold Porto Grande
858.052/02 Mneração Serra da Canga Ltda Pending appeal 8,064.79 Tucano

Final report

presented

1,362 19 Jun 2006   N/A   Gold Serra do Navio e Ferreira Gomes
858.077/09 Beadell Brasil Ltda Partial report submitted 123.92 Tucano

Final report

presented

14,560 10 Dec 2009   N/A   Gold

Pedra Branca do Amapari e Porto

Grande

858.054/04 Beadell Brasil Ltda Partial report submitted 971.40 Tucano

License extension

requested

859 24 Jan 2005   N/A   Gold Pedra Branca do Amapari
858.029/13 Beadell Resources Mineração Ltda Partial report submitted 919.03 Tucano

License extension

requested

835 29 Jan 2014   N/A   Gold & iron

Pedra Branca do Amapari e Porto

Grande

858.015/12 Beadell Resources Mineração Ltda Partial report submitted 8,280.13 Tartarugalzinho

License extension

requested

1,153 9 Apr 2012   N/A   Gold Tartarugalzinho
858.032/12 Beadell Resources Mineração Ltda In progress 8,476.34 Tartarugalzinho

License extension

requested

3,643 19 Apr 2013   N/A   Gold Tartarugalzinho
850.858/87 Mineração Vale dos Reis Ltda

Partial report submitted /

total assignment submitted

5,643.84 Tucano

License extension

requested

325 6 Jan 2014   N/A   Titanium Serra do Navio e Pedra Bca Amapari
858.002/11 Mneração Serra da Canga Ltda

Partial report submitted /

pending appeal

76.90 Tucano

License extension

requested

9,522 4 Jul 2011   N/A   Iron Porto Grande
851.676/92 Beadell Brasil Ltda In progress 3,971.41 Tucano Mining concession 73 13 Apr 2004   N/A   Gold Pedra Branca do Amapari
852.730/93 Zamin Amapá Mineração Ltda In progress / leasehold 5,529.63 Duckhead Mining concession 91 6 Apr 2009   N/A   Gold & iron Pedra Branca do Amapari

 

 

amcconsultants.com

36

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 4.2 GPR tenement ownership map with tenement status

Source: BDR

 

 

amcconsultants.com

37

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Tenements that are under one of the phases following do not have an expiration date (in some of these cases it depends on an analysis / decision by the ANM. For such reason the wording “N/A” has been used in the schedule with respect to expiration date: Application for Exploration, Partial Leasehold (Duckhead lease), Bid, Exploitation Application, Final Report Presented, License Extension Requested, or Mining Concession. “Bid” means the processes which are currently under a public tender process, in which interested companies have presented their proposals but the ANM has not analysed yet.

The following tenements are discussed further:

858.008/2018; Awaiting confirmation from ANM regarding the area requested by BDR (6,002.44 ha) being accepted by ANM.
858.010/1999 - An area of 8,634.00 ha was the size of the area that BDR was qualified for in the availability notice. Availability to date is on appeal. The area is exclusive of 930.73 ha of the Zamin mining concession area within the tenement 858.010/1999.
852.730/1993 -An area of 5,529.63 ha was the size of the area that BDR was qualified for in the availability notice. Availability to date is on appeal.
4.4Royalties and agreements

GPR is subject to both federal and state royalties and other royalty agreements in relation to mineral product sales from its Tucano Gold Mine.

In summary these are; (a) the Compensation for Exploitation of Mineral Resources (CFEM), (b) the Control, Monitoring and Supervision of Research Activities, Mining, Exploration and Exploitation of Mineral Resources Fee (TFRM), (c) the Social and Community Development Funds, and (d) a Commodities Royalty.

CFEM is a federal royalty and is calculated over the amount of gross revenue obtained in the sale of mineral products. In respect of gold sales, the company is liable to pay a royalty of 1.5% on gross revenue from production at its Tucano Gold Mine.

TFRM is a state royalty levied by the state of Amapá, in which GPR’s Tucano Gold Mine is located. TFRM is currently calculated based on the grams of gold produced multiplied by the state index rate of BRL2.25 which multiplied by a factor of 0.4. The Company has recently finalized negotiations with the state of Amapá to reduce the factor applied; 0.1 for the 2018 and 2019 years and 0.25 for the years 2020 and beyond. The reduced factors have not yet been enacted into law.

The Social and Community Development funds have resulted from various agreements with the state of Amapá and the municipalities of Pedra Branca do Amapari and Serra do Navio. The municipalities of Pedra Branca do Amapari and Serra do Navio are located nearby the Tucano Gold Mine.

Under the terms of the agreements the Company will pay a maximum 1% royalty over the gross proceeds from gold sales from the Tucano Gold Mine to support the socio-economic and community development of the municipalities of Pedra Branca do Amapari and Serra do Navio.

The Commodities Royalty is payable to the previous holders of 13 tenements acquired by GPR. The Commodities Royalty is levied at 0.75% of commodity sales revenue arising from those 13 tenements minus taxes, transport and insurance expenses and royalties payable.

amcconsultants.com

38

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

4.5Environmental liabilities

The Project area is an active mining operation centred in dense tropical rain forest located in Amapá State, Brazil, consisting of open pit operations, crushing, milling and CIL processing that has a direct impact on the environment and the ecosystem of the region. The main impacts are on biological resources, air quality, noise and vibration, archaeology, hydrogeology and hydrology (ground and surface water), and community stakeholders.

4.6Permits and other

All permits are in place for the Project. A recent field trip by Marcelo Batelochi the QP for the environmental - Section 20, has confirmed that all relevant monitoring and reporting to government environmental agencies is being undertaken as per legislation and that the mine site is fully compliant in the areas of:

Characterization of Flora and Fauna.
Documentation and retrieval of archaeological artefacts.
Fauna monitoring programs.
Vegetation clearing and rehabilitation processes.
Dust, emissions and noise control.
Control of drainage and erosion.
Monitoring of surface and ground water.
Classification and management of industrial solid and liquid wastes.
Environmental emergency plans
Details of funding for community development programs.
Positive impact on the state economy through employment.
Development of educational programs for the community.
Support in maintaining local community infrastructure and services.

 

amcconsultants.com

39

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

5Accessibility, climate, local resources, etc.
5.1Accessibility

The Property is located at latitude 0.85°N and longitude 52.90°W, approximately 200 km northwest of Macapá, the capital of Amapá state in northeast Brazil. Access to the site is made via road or by chartered aircraft.

Road access to Tucano is made using Brazilian federal highway BR-210 from Macapá. The first 100 km of the highway from Macapá is sealed - the balance of the road is unsealed. Total driving time from Macapá to the site is approximately four to six hours, depending the season and on road conditions.

The Tucano mine site is also serviced by a 1,100 m airstrip located approximately 800 m from the main gate. Charter flights from Macapá to the mine take about 50 minutes.

The nearest accessible community to the Tucano operation is the town of Serra do Navio, with a population of approximately 3,300. It is located adjacent to the Amapari River and is approximately 200 km from Macapá. Macapá has a population of approximately 474,000 and lies on the equator on the north side of the Amazon River. Most of the workforce are transported by bus from Serra do Navio, Pedra Branca and other small surrounding towns. Professional staff commute from either Macapá or other cities in Brazil on a fly-in-fly-out (FIFO) basis.

5.2Physiography

The Tucano project is situated in low hills to the north of the Rio Amapari valley. The original heap leach pad and the plant site was cut from the top of existing hills. The ground drops away quickly to the east of the process plant, first into the valley of Igarapé Taperebá (Taperebá Creek) and then into the valley of the Igarapé William (William Creek). The Taperebá AB pit complex is on the other side of Igarapé William and is bounded on the east by some slightly higher hills. The process plant is at an altitude of approximately 170 m above sea level and the adjacent Igarapé William valley about 110 m above sea level. The hills behind the Taperebá AB pits rise to a height of about 320 m above sea level and form part of a ridge running along the eastern side of Igarapé William. The area is located within tropical forest, with a high vegetation density.

5.3Climate

The Project site is located in an area considered to have an equatorial climate, typified by year round high humidity and rainfall. The wet season occurs from January to June and is associated with frequent torrential rain events of long duration. Less rainfall is received during the remaining months however rainfall events are still frequent. Measurements of site rainfall between 2008 and 2016 inclusive show an average annual rainfall of 2,259 mm. Table 5.1 and Figure 5.1 below show the monthly rainfall measurements for 2008 - 2016. According to the Brazilian Water Agency (ANA), average monthly evaporation rates range from 800 mm (February to April) and 1,900 mm (August to October), with an annual evaporation of 1,424 mm.

amcconsultants.com

40

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 5.1 Monthly rainfall at Tucano from 2008 to 2016 inclusive

Year Jan Feb Mar April May June July Aug Sept Oct Nov Dec Total
2008 262 225 358 292 442 258 319 30 90 77 5 150 2,507
2009 208 404 218 247 413 263 178 51 11 34 5 150 2,181
2010 304 225 262 334 268 160 196 184 57 33 91 186 2,300
2011 249 244 306 320 317 160 238 147 43 95 69 71 2,257
2012 222 281 257 240 182 166 171 109 41 104 52 218 2,043
2013 218 268 196 284 236 103 248 209 104 72 24 151 2,115
2014 196 361 297 303 474 233 145 88 58 133 65 64 2,417
2015 233 318 278 362 367 191 164 45 38 34 29 145 2,204
2016 255 213 447 362 165 267 189 73 64 54 9 208 2,306
2017 331 259 283 276 192 302 88 99 123 130 36 224 2,343
Average 248 280 290 302 306 210 194 104 63 77 38 157 2,259

Figure 5.1 Monthly rainfall at Tucano from 2008 to 2016 inclusive

Source: BDR

5.4Infrastructure

Infrastructure at the Tucano Mine site includes a central administration building and medical facility, offices (mining, geology, survey, mining engineering, supply, environment, and safety), core shed, nursery, light and heavy equipment workshops, warehouse storage facilities, tire shop, refuelling and washing bays, fire-fighting systems, and explosive magazines. The project also encompasses a CIL gold plant with administration buildings, workshop, a power generation and distribution facility, security office, sample preparation and assay laboratory, storage area, and a reagent preparation facility. Mine subcontractors have separate facilities.

Site communication comprises private branch exchange (PBX) telephone systems and internet links.

All installations are fenced and monitored by armed guards and cameras. The main entrance to the site is located at the main site access road. A 122 person accommodation camp is located near the access road to site. This camp is well equipped and includes a gymnasium, games room, laundry, and restaurant area.

amcconsultants.com

41

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Doctors and nurses are stationed on the site permanently. An established system is in place for emergency removal of personnel if required.

5.4.1Water

Water is provided from water storage dams and recycled process water. Potable water is processed onsite through a potable water treatment plant, where it undergoes filtration and chlorination to produce water of drinkable quality. The water is transferred from the potable water treatment plant into two potable water tanks.

Process water consists of recycled and other waste streams used in the process, including return water from the Tailings Storage Facility (TSF).

5.4.2Power

The site is connected to the national electrical grid by a 69 kilovolt (kV), 20 megavolt-ampere (MVA) power line via the state-owned Centrais Elétricas do Amapá (CEA - the local supply authority), and an independent 12 MW continuous rated Aggreko diesel-powered generation system.

5.4.3Workforce

The mine currently employs a total of 1,116 persons, comprising 416 employees and 700 contractors. With the exception of a few senior management staff and the expats working for contract companies MACA and McKay, all staff (approximately 99%) are Brazilian nationals. The majority of the workforce live in towns in close proximity to the mine site. Managers and professional staff either commute from the state capital Macapá or from other cities in Brazil on a FIFO basis.

Shift workers work a rotating 8 hr shift over a 24-hr period with a roster in days of 6 on 1 off, 6 on 2 off, 6 on 3 off basis. Managers and professional staff either work a roster in days of 19 on, 9 off or 5 on, 2 off. Expats work on a FIFO basis of 6 weeks on, 3 weeks off.

5.4.4Commercial resources and services

Contracted services and the procurement of goods is managed by the site supply department. Many of the ancillary services required by the site are located in Macapá (e.g. cleaning, transport, and catering). Larger construction projects such as the process plant and tails dam expansion are contracted using companies based in Para and Mina Gerais. GPR will establish long term contracts with companies in Belo Horizonte, which is the hub for many mining industry services in Brazil. The supply of materials is either directly out of Macapá or shipped in from other cities via the port of Belem to the port of Santana located 10 km from Macapá.

5.4.5Transportation

The mine site is located approximately 200 km from Macapá. This access comprises:

Sealed road for approximately 100 km, from the city of Macapá to Porto Grande.
Unsealed road from Porto Grande to Pedra Branca do Amapari, approximately 70 km.
Unsealed road from Pedra Branca do Amapari to the site, approximately 30 km.

The journey from Macapá to site takes approximately four hours by car during the dry season and up to six hours during the wet season, depending on the condition of the unsealed roads. The unsealed roads are passable all year around and no blockages are experienced except during road maintenance. The transport of personnel, bulk materials, fuel, and other supplies passes over various bridges along the route to the mine. These are mostly wood construction material and are limited to a 45 t of total load (carrier plus load). Most of the bridges have been upgraded recently, allowing for a reliable means of transport to the site.

amcconsultants.com

42

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

6History

Anglo American discovered a mineralized shear zone in 1994 and undertook extensive exploration between 1995 and 2002. AngloGold completed a feasibility study of the oxide resources in October 2002.

The mine was subsequently acquired by EBX Gold Ltd (EBX) in May 2003. EBX carried out a feasibility study for the oxide mineral resources and a prefeasibility study for mining the sulphide ore.

The property was acquired by Wheaton River Minerals Ltd (which later merged with Goldcorp Inc) in January 2004. Mine construction began in July 2004, with the first gold production in late 2005. The mine then operated as Brazilian company Mineração Pedra Branca do Amapari (MPBA) as a heap leach operation until 2 January 2009, when it was placed on care and maintenance. A significant factor in the decision to close the operation was the increasing occurrence of transition material in the pits and an inability to treat this material economically with the existing process route.

Goldcorp Inc sold the mine to Peak Gold Ltd in April 2007. Peak Gold Limited later merged with New Gold Inc.

The operation suffered from problems with handling the clayey nature of the saprolitic oxide ore and did not reach the predicted recoveries. In response to the operational problems, some test work was conducted on site during 2007 to investigate the potential improvements from installing a wash-plant (integrated with downstream CIL facilities and oxide and sulphide milling circuits) to remove fines and clays and improve heap percolation characteristics. However, it was not possible to reach firm conclusions regarding the potential benefits of the proposed wash plant. As a consequence of the test work ambiguities, continued heap leach improvements and the relative shortage of oxide resources, the plans for the integrated wash-plant and oxide and sulphide milling circuit were put aside in favour of a milling and CIL circuit to treat predominantly sulphide plus remnant oxide material.

Until closure in 2009, mining operations extracted 8.8 Mt of gold ore from four areas, Taperebá (Tap) AB (pits 1, 2, and 3), Tap C, Tap D, and Urucum. Total gold production from the heap leach operations was approximately 292,000 oz.

amcconsultants.com

43

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

7Geological setting and mineralization
7.1Regional geology

The South American Precambrian Shield comprises some 50% of the bedrock in Brazil and consists of major Proterozoic deformation zones surrounding cratonic nuclei of Archean age. The three principal cratons are the Guyana Craton in the north, the Amazon (or Guapore) craton immediately south of the Amazon River, and the São Francisco Craton situated between the Amazon Craton and the coast. The cratons are mostly a granite gneiss complex including some highly metamorphosed supracrustal belts, of which greenstone belts represent a small portion. Remoteness and lack of outcrops due to deep weathering prevent detailed stratigraphic and structural mapping across most of the greenstone belts. However, stratigraphic and structural elements typical for greenstone belts worldwide are well recognized in most South American examples.

The consistent north-easterly trend of inferred extensions within granite-greenstone belts across north-eastern South America suggest they have formed during a single major event. The Tucano mineral deposits are located within the Guyana Craton, described by several authors as the Maroni - Itacaiunas mobile belt. This belt runs from Pará and Amapá States of northern Brazil through the Guyanas and into Venezuela. The regional structure is marked by a north-western trending foliation parallel to the main lithologic contacts. Figure 7.1 below shows the basement geology overlain with the Property outline.

Figure 7.1 Geology map of basement geology overlain by the Property tenements

Source: BDR

amcconsultants.com

44

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

7.2Property geology

The western part of the Property (about 25% of the area) is underlain by basement gneiss. The balance of the Property area is underlain by ortho-amphibolite and meta-sedimentary rocks of the Vila Nova Group (1.75 to 1.9 billion years old), composed essentially of gneisses, granites, amphibolites, banded iron formations (BIF), massive iron formations, schists, and quartzites (Table 7.1). These units are intruded by granitic pegmatites, diabase dykes, and gabbro bodies. The metasediments are similar to what has been named the Serra do Navio Formation in the nearby area that was mined by Indústria e Comércio de Minerios S/A for manganese. The metasediments hosting the gold mineralization within the Tucano property lie along the limb of a syncline (Figure 7.2).

On the south end of the syncline, the strike is north-south, with dips approximately 65 degrees to the west. To the north the dip becomes vertical to dipping slightly northeast, with the strike trending north-northwest. The gold mineralization is associated with iron and carbonate-rich units of the chemical sedimentary sequence known as the William Formation (Table 7.1). Gold mineralization is predominantly associated with the BIF facies, but carbonate and calc-silicate rocks also host economic mineralization. Sub-economic mineralization may be hosted by any of the lithological units shown in the stratigraphic column (Table 7.1) except the late intrusions.

Laterite and lateritic colluvium are common throughout the area and tend to be thicker over topographic highs, with thick laterites developed in proximity to BIF. Colluvium is characterized by deeply weathered rock that no longer displays any trace of original structure and commonly has angular fragments that indicate limited transport. The colluvium hosts secondary mineralization. A north-south trending shear zone appears to control gold mineralization by carrying gold-bearing hydrothermal fluids or remobilizing existing mineralization; this can be justified by the presence of mineralization found in BIF that was not deformed by shearing. Mineralization is both conformable and not conformable with meta-sedimentary contacts in the William Formation.

amcconsultants.com

45

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 7.1 Stratigraphic column (from AMC 2009)

Alluvium / laterites
  Intrusives Basic Db Gabbro / diabase Dykes of diabase and gabbro
Acid Gran. / Peg Pegmatites

Vila

Nova

Group

Clasto-pelitic

Sedimentary Unit

Quartz

Domain

QMX Muscovite quartzites

Muscovite-quartz schist,

muscovite quartzite, locally with

fuchsite and / or sillimanite

Pelitic

Domain

QBX Quartz-mica schists

Quartz-biotite-muscovite schist

with garnets, interspaced with

lenses of calc-silicates, iron

formation and muscovite

Clasto-chemical

Sedimentary Unit

Transitional

Unit

RANF

Quartz-grünerite

cummingtonite

schist w/ garnets,

chlorite and biotite

Quartz-amphibole schists and

amphibole schists with lenses of

silicate facies iron formation and

calc-silicates

Chemical

Sedimentary Unit

(William Fm.)

Ferruginous

Domain

FFER

Iron formation,

silicate facies

Garnet-hornblende-grünerite-

diopside; magnetite-grünerite-

hornblende schists

BIF-O

Iron formation

oxide facies

(Grünerite)-quartz-

magnetite / hematite, sometimes with

garnets and diopside

BIF-OS

Iron formation

oxide-silicate facies

(Hornblende)-diopside-grünerite-

quartz with magnetite; (diopside)-

hornblende-garnet, quartz-

magnetite-grünerite schist

Calc-

magnesian

Domain

CALC

Schists with

diopside porphyroblasts

Actinolite-tremolite-diopsides,

hornblende-diopsides, amphibole-

diopsides, with epidote, biotite

and garnets

RCB

Marble and

carbonate schists

Calcic marble, serpentine marble

with tremolite, forsterite, fayalite,

hastingsite, chlorite and

magnetite; actinolite-tremolite-

carbonate schists

Volcanic Unit   MTB or ANF

Metabasics ortho-

amphibolites

Plagioclase amphibolite’s, biotite-

amphibole schists, plagioclase-

cummingtonite-hornblende schists

 

amcconsultants.com

46

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 7.2 Property geology map

 

Source: BDR

In Figure 7.3 the Tucano deposit is shown on a lithology background along with some infrastructure. The circled areas show key near mine exploration targets.

amcconsultants.com

47

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 7.3 Tucano deposit location map

 

Source: BDR

7.3Local geology and mineralization

The mineralization at Tucano occurs in a series of deposits over a 7 km strike length associated with a north-south trending shear zone occurring coincident with a north-south line of topographic ridges. From south to north, these deposits have been named Tap A, B, C, and Urucum. Tap D is a separate structure in the west. The locations of the deposits are shown in Figure 7.3. Higher grades are associated with the more intensely hydrothermally-altered rocks.

Continuous high grade shallowly plunging ore lodes are developed along mineralized shear zone hosts. The geometry and plunge of the ore shoots is interpreted to be controlled by gently plunging F2 fold hinges and more steeply dipping fault intersections.

amcconsultants.com

48

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The texture and mineralogy along the shear zone indicates a high-temperature hydrothermal system. The interaction of favourable rock type, structure, heat, and mineralized solutions has resulted in the deposition of gold bearing, non-refractory sulphides concentrated near or on major lithological contacts. This mineralized zone exhibits intense hydrothermal alteration, particularly silicification and sulfidation, bearing auriferous pyrrhotite, and pyrite. Alteration is most intense in the proximity of reactive meta-sediments such as BIF, followed by amphibolite, carbonate, schist, and to a lesser extent, calc-silicate rocks. Table 7.2 below shows a description of length, width, depth, and continuity for each deposit.

Table 7.2 Description of mineralized zones in each deposit

Deposit Pit / area

Total horizontal

length of

mineralization (m)

Average

width (m)

Depth

defined by

drilling (m)

Continuity of

mineralization down

plunge (m)

Tap AB Tap AB1 580 9 300 450
Tap AB2 600 5.5 350 440
Tap AB3 420 5.5 460 480
Tap C Tap C1 800 6 150 150
Tap C3 450 7 300 150
Tap C3N 350 5.5 90 150
Gap 170 11 130 100
Urucum Uucum North 1,000 4 780 550
Urucum South 1,300 10 360 750
Urucum East Urucum East 230 7 75 180
Duckhead Main Lode 80 12 210 220
HW Lode 90 15 165 180
7.3.1Tap AB and Urucum

The Tap AB and Urucum Gold Deposits of the Tucano Gold Project are emplaced within a north-south trending, multiply deformed volcano-sedimentary sequence of rocks that is bounded to the west by the Amapari Granite. The deformation history has resulted in steeply dipping N-S shear zones and the gold mineralization is associated with alteration and sulphide mineralization of various lithologies within the deformed sequence. Mineralization occurs over at least 7 km of strike length and has been interpreted to extend to more than 700 m below the surface. A suite of late post-gold pegmatites has been emplaced throughout the sequence in various orientations and is largely barren of gold.

Mineralization also occurs in colluvium overlying the sequence and this mineralization is spatially related to the bedrock mineralization and is interpreted to be derived thereof. Typically for many deposits of its type, the mineralization often presents as generally somewhat discontinuous and irregularly distributed on the scale of approximately 50 m to 100 m. Figure 7.4 presents a sectional view from Tap AB 30 m apart demonstrating variability in grade, thickness, and orientation of gold mineralization.

Gold mineralization at Urucum is predominantly strata bound to specific sheared lithological units within the BIF and is characterized by strong disseminated and shear fabric pyrrhotite sulphide. The strong association between gold and pyrrhotite results in a highly visual ore in fresh rock that is easily discernible from non-mineralized BIF and other rock.

The Urucum underground resource covers a strike length of approximately 800 m down to a depth of approximately 500 m below the open pit. The lodes form continuous subparallel ore shoots hosted within an approximately 100 m wide Banded Iron Formation (BIF). Three main ore lode horizons have been defined by the drilling and are named Lode 1, Lode 2, and Lode 300 with each lode dipping sub vertically and generally separated by 20 m to 30 m. The average true width of each lode is 4 m.

amcconsultants.com

49

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 7.4 Tap AB Gold Deposit section 94,550 mN

Source: BDR

amcconsultants.com

50

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

7.3.2Urucum East

The Urucum East deposit is located east of the Urucum Mine in the northern anticlinal fold hinge of the Tucano mine stratigraphy. The deposit consists of a single, east-west striking and flat (-30°) north dipping sulphide lode which has an average thickness of 7 m and a strike length of 230 m. Mineralization at Urucum East is hosted in a wedge of carbonate and altered banded iron formation located inside a swarm of parallel, east-west striking and -30° north dipping pegmatite dykes which have intruded the host schist unit. The deposit is covered by a blanket of poorly mineralized colluvium up to 10 m thick and weathered to a depth of approximately 50 m below the surface.

7.3.3Duckhead

Mineralization at Duckhead is controlled by the recently interpreted intersection of steep east-west striking shear zones with a banded iron formation lithological contact to form steeply west plunging high grade shoots. The texture and mineralogy along the shear zone indicates high-temperature hydrothermal alteration, particularly silicification and sulfidation, bearing auriferous pyrite.

7.4Mineralization weathering types

Deep weathering is present in a majority of the deposits with high grade mineralization extending right to the surface through a layer of colluvium several metres thick. Gold mineralization can be found in the fresh rock at depth, in the saprolite zone created by insitu weathering of the underlying rocks and also in colluvial deposits which overlie the saprolite mineralization as a blanket, spreading out over the hill slopes. The saprolite and the colluvial mineralization are collectively grouped together as ‘oxide mineralization’.

Sulphide zones follow shear plane foliation, often crosscutting the BIF and other host meta-sediments and as bedding parallel lenses dipping either east or west along the limbs of the folded BIF units. Host rocks are poor in sulphide and gold, outside the shears and faulted zones. The accumulation of auriferous massive and / or disseminated sulphides in zones of fractures and folds, and forming plunging ore shoots, often crossing lithological contacts, suggests an epigenetic or remobilization event.

7.4.1Primary or sulphide mineralization

Sulphide mineralization within fresh rock is only found in drill core and does not outcrop at Amapari. Pyrrhotite and pyrite are the most abundant sulphides. Chalcopyrite, arsenopyrite, sphalerite, and galena occur in trace amounts (less than 1%). At Urucum, the mineralization occurs with intense silicification and pyrrhotite is the dominant sulphide. At Tap AB the gold is associated with masses containing 5% to 10% pyrite, and pyrrhotite only occurs in trace amounts.

The individual sulphide masses are several metres thick and can be elongated on strike along north-northwest or north-south orientations. The sulphides extend in depth along a plunge dipping from 10º to 40º at about N10ºW. The dip ranges from almost vertical at Urucum, to 30°W at the south of the Tap AB deposit. Studies show that the gold occurs as free gold and not tied into the crystal lattice of the sulphide minerals. Mineralization is not confined to any particular lithology, nor is it concordant with lithological contacts.

7.4.1.1Saprolite mineralization

Intense tropical weathering reaching down 30 m to 300 m has caused the formation of saprolite, that is, an in-situ oxidation of the primary sulphide mineralization and host rocks. The saprolite consists mainly of iron oxides and hydroxides, clay, and silica. Ore zones within saprolite follow the strike, dip, and plunge of the primary sulphide mineralization. Semi-decomposed remnants of the primary mineralization become more frequent with depth.

amcconsultants.com

51

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Weathering has left much of the saprolite material amenable to free-digging but some of the saprolite has required blasting prior to excavation. The mineralization in these more competent zones may range from entirely oxidized to partially or even completely primary sulphides.

7.4.2Colluvial mineralization

The colluvial deposits occur along north-south trending ridges cut by William Creek. The creek is at about 115 m elevation and the ridges reach 300 m. The top and slopes of the ridges are covered by alluvial and colluvial sediments. It is difficult to separate alluvial and colluvial sediments in the field and therefore they are collectively named colluvium.

All primary ore shoots are covered by mineralized colluvium, which vary according to the subsurface lithology. The grade of mineralization in colluvium tends to reflect the grade of underlying ore shoots, with patches of low grade or barren colluvium usually reflecting low grade or barren underlying saprolite zones. However, zones of mineralization in colluvium tend to be wider than in underlying saprolite due to mechanical transport and development of some secondary mineralization due to variations in surface soil chemistry.

Deep weathering and intense fixation of iron in the upper portions of the soil often create a laterite horizon. The top of the colluvium is usually a layer rarely more than 1 m thick composed of silty, clayey, and sandy materials, poor in fragments of limonite. Immediately below there is a variable layer up to 10 m thick containing lateritic fragments rich in iron oxide dispersed in a ferruginous clay-sand matrix which becomes rich in manganese at the base.

The colluvium deposits are heterogeneous, reflecting the varied subsurface lithologies. Occasionally there are semi-decomposed, angular fragments of these lithologies within the colluvium.

amcconsultants.com

52

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

8Deposit types

The gold deposits at the property are hosted within shear zones within a number of different Paleoproterozoic, metasedimentary host rocks. This mineralization style is considered to represent an orogenic, structurally controlled gold mineralizing system. The strong association of gold mineralization within and proximal to a major BIF unit makes the setting of the Tucano deposit unique in the district however the age and shear structural controls show similarities to Birimian Orogenic Gold District deposits in West Africa. Figure 8.1 shows a reconstruction of the Guiana Craton with the West Africa Shield showing the location of the major gold deposits in the area. Deep and highly variable thickness weathering is a feature shared by Tucano with other gold deposits in the Guiana Craton.

Figure 8.1 Reconstruction of the Guiana Craton and West Africa Shield

 

Source: BDR

amcconsultants.com

53

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

9Exploration
9.1Airborne magnetics, radiometrics, and DEM

The Property has been covered by an airborne magnetic, radiometric, and Digital Elevation Model (DEM) survey conducted for previous operator, AngloGold in 1998. The survey was flown by LASA Engenharia e Prospecções S.A covered a total area of 10,377 km2 on 250 m spaced lines at an elevation of 100 m. Two areas; "AP1" (Eastern Area) and "AP2" (Western Area) were flown. In 2001 Spectrem Air Ltd conducted an airborne geophysics program for AngloGold involving magnetic, electromagnetic, radiometric, and DEM on 200 m spaced lines. In 2004, CPRM - Serviço Geológico do Brasil (Geological Survey of Brazil) flew a government funded airborne magnetic, radiometric, and DEM survey covering the Araguari River Project area in Amapa state. The survey covered 10,872 km2 at an elevation of 110 m and a line spacing of 500 m. The justification for the 2004 program was on the basis that geological characteristics indicated potential for gold, base metals (copper and others), and chromium.

During 2015, BDR contracted Southern Geoscience Consultants (SCS) in Australia to merge and re-process both airborne and ground geophysical datasets. For the airborne magnetic datasets, the "AP1" survey was excluded as it was superseded by the higher resolution SPECTREM survey. The processing of the airborne magnetic datasets involved re-projection to a common SAD69 22N datum, re-gridding, merging, and filtering. The merged Total Magnetic Intensity (TMI) filters used included:

RTP; Reduction to Pole
1VD; First Vertical Derivative
AS; Analytical Signal of the TMI
ASVI; Analytical Signal of the Vertical Integral of the TMI.

A Total Magnetic Image (AS) from the SCS merged data along with the Property outline is shown in Figure 9.1. BIFs and late cross cutting diorite dykes are shown as magnetic highs in red.

In 2015 SCS also merged all four datasets for Radiometric elements; K, U, Th, and TC (total count) using a grid cell of 100 m for the Araguari dataset and 50 m for the others. K and U were not used from the SPECTREM dataset due to problem with the processing of these channels. Prior to merging the data was scaled and levelled using a histogram approach.

amcconsultants.com

54

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 9.1 Merged Airborne Magnetic Total Magnetic Image (AS)

 

9.2Airborne electromagnetic survey

In January 2001 SPETREM Air Ltd flew an airborne electromagnetic (AEM) survey over the Amapa area for previous operator, AngloGold. A total of 4,601 acceptable line kilometres of data were collected on 200 m spaced lines before the bird (sensor) was lost and thus an estimated 750 line kilometres were never captured. In addition to AEM, aeromagnetic, radiometric, and DEM data were also collected. A large number of good bedrock conductors were identified in the largely resistive environment. Most of these conductors seem to be due to carbonaceous units although many of those could also be ascribed to sulphide-rich horizons. A number of conductors were identified as BIF with associated sulphides are of interest as gold exploration targets. High conductivity-thickness product AEM anomalies with a magnetic association are probably indicative of pyrrhotite rich sulphide conductors.

The SPECTREM data did not require levelling or filtering by SCS in 2015 as it was deemed to be of good quality. The data was re-gridded to 40 m to improve image detail.

amcconsultants.com

55

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 9.2 SPETREM electromagnetic image

 

9.3Ground geophysics

In 2004 previous operator, MPBA contracted EQUIPE AFC GEOFÍSICA LTDA to carry out ground geophysics using the following methods; Magnetometer, Very Low Frequency (VLF), and Induced Polarization, Time Domain (IP) over the projects of Tap AB, Tap D, Urucum, Vila do Meio, and Urucum East. The first stage of the geophysical survey was to base-line against known mineralization at Urucum, Tap D, and Tap AB already defined by 4 lines drill ranging from 300 m to 800 m in length. This involved magnetometer, VLF, and IP time domain surveys.

At Vila do Meio and Urucum East only, IP and magnetometer were used with 8 lines completed and a total of 6,100 and 8,350 line metres respectively. At the first stage, spacing of the magnetometer readings was 10 m and IP dipole-dipole arranged on a 25 m spacing on short lines up to 400 m with a combination of di-pole and gradient array on the longer lines up to 800 m. At Urucum East and Vila do Meio magnetometer reading spacing was at 25 m and IP dipole was at 50 m with some lines employing a combination of dipole and gradient array. Mineralization from all lines in stage 1 was detected with IP. The magnetometer was excellent in defining the Iron Formation. Conductors in areas without drill information were identified and flagged for follow-up work.

In 2015 SCS processed the ground magnetic data for Vila do Meio for BDR with the aim to provide information in the SPECTREM data gap area however the resolution of the image was considered poor. It was recommended to close the reading spacing to 10 m to improve resolution. A review of the ground IP dataset was not undertaken by SCS.

amcconsultants.com

56

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

9.4Petrophysics

In 2016, BDR contracted Western Geoscience Pty Ltd to undertake physical property test work on selected drill cores for the Tucano project. Results confirmed that pyrrhotite mineralization was insufficient concentration to be conductive. IP surveys have been proposed to test targets in the Tucano trend for possible sulphide conductors at depth. Table 9.1 below shows the test results of a sample of pyrrhotite rich ore from Urucum along with a photo of the core (Figure 9.3).

Table 9.1 Conductivity test results of a sample of pyrrhotite rich core from Urucum

Id No. reading Grade (ppm Au) CondS/m MSus10-3
1 1   1,305.00 2.61
1 2   1,545.00 2.83
1 3   832.00 2.85
1 4   815.00 2.06
1 5   517.00 2.43
1 6   855.00 2.45
Average   48.1 978.17 2.54

Figure 9.3 Photo of the conductivity test sample

 

9.5Geochemistry

Previous operator, AngloGold had conducted extensive soil sampling across the Property. Results show soil anomalism over many areas, some of which require base line levelling due to a several methods of analysis and various detection limits being used. BDR has assessed this data along with an interpretation of the geophysics and geological mapping as part of its exploration target generation and ranking review. Figure 9.4 below shows the coverage of existing soil sampling and tenement status. It illustrates that for many tenements, first pass soil sampling is still to be completed. BDR has undertaken soil sampling in its exploration tenements using 400 m spaced lines and 40 m sample intervals with infill sampling closing down to 200 m spaced lines. Soil samples around 1 kg are collected from the B soil horizon using a post hole digger to a depth of 30 cm to 50 cm. Table 9.2 below shows the breakdown of sampling work undertaken by tenement.

BDR carried out an extensive program of stream sediment sampling in 2017 with a method of fine fraction (200 mesh) BLEG analysis. Samples were collected at approximately 700 m spaced centres, typically 1 sample per tributary stream. The sampling involved collection of one composite of 35 sample points along a 100 m stretch of the stream collection point. The method has so far proved effective in identifying a large anomaly in the Serra da Canga East area and is now the subject of a follow-up soil grid sampling program. Figure 9.5 shows the extent of the Serra da Canga stream sediment anomaly.

amcconsultants.com

57

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 9.4 Tenement status map showing the coverage of soil sampling

 

Table 9.2 Number of exploration samples collected by sample type and company

Company Sample type No. samples
Anglo Gold Soil 78,134
Anglo Gold Stream sediment 1,349
Anglo Gold Rock chip 3,674
BDR Soil 3,907
BDR Stream sediment 263
BDR Rock chip 1,073

 

amcconsultants.com

58

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 9.5 Serra da Canga East stream sediment anomaly

 

9.6Geological mapping

The tenement package has been extensively mapped by the previous company MPBA and work continued under the direction of BRD's regional exploration team. Outcrop is generally scarce however the composition of the soil and colluvium cover gives indicators to the underlying geology and this in combination with the geophysics aids in the geological interpretation. Mapping usually occurs in conjunction with soil sampling along defined sampling lines.

amcconsultants.com

59

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

10Drilling
10.1Drilling methods

Auger, RAB, RC, and Diamond Drilling methods are employed at Tucano. Auger drilling is undertaken using a three-man crew operating a man-portable motor driven auger drill with a barrel cutting bit to collect a core sample of loose friable material. While unable to penetrate hard laterite or large rock fragments this can penetrate up to 21 m in softer material with average depths of around 4 m commonly achieved. This is also a useful tool aid for mapping as Tucano and the surrounding district is covered by an extensive colluvium blanket and outcrop is often rare.

RAB drilling is undertaken by a mine owned track mounted PW blasthole rig trailing an air compressor, it is used exclusively by geology for both grade control and exploration. The rig is capable of penetrating to 30 m but is generally used to test to depths of around 4 m to 8 m. It is used where access is difficult to undertake grade control in the mine with RC drilling. Also provides a rapid means to drill test exploration targets with a minimal amount of clearing required, especially where there is extensive laterite development in the regolith.

RC Drilling uses a track mounted Schramm T60 with a track mounted auxiliary booster operated by McKay Sondagens (a Brazilian company established by the Australian owned parent company McKay Drilling). The rig has a mounted cyclone and cone splitter which are both accessible for cleaning during drilling operations. The rig has previously drilled to depths of 400 m and is the main tool used for in-pit grade control as well as resource extension and definition work.

Diamond drilling utilizes two skid mounted Brazilian Maquesonda Mach 1200 diamond rigs operated by Brazilian drilling contractor Geosol. The rigs have previously drilled up to 878 m on site and are mainly employed to drill deeper underground resource extensions.

10.2Surveys and survey coordinate system

Drillhole collar locations and the collar azimuth and dip of the drill rods string are surveyed using a Total Station Leica 407 in the SAD69 22N coordinate system. Downhole surveys for the RC drilling are undertaken using a Reflex Gyro tool. Downhole surveys are collected in diamond holes utilizing a Reflex Maxibore II. These surveys are generally undertaken every 100 m as the hole progresses (i.e.: 0 - 100 m, 0 - 200 m, 0 - 300 m, etc.) to monitor drilling deviation. Maxibore survey data is collected on 3 m intervals during each survey. Geology staff check survey data for repeatability.

10.3Diamond drill core

Diamond core drilling utilizes both HQ2 and NQ2 diameter core. Normally holes are started utilizing HQ2 size in oxide and are reduced to NQ2 once fresh rock is encountered. Drill core is orientated with a Reflex ACT III orientation tool in fresh rock. Core orientations and depths are checked by site geologists and core yard personnel for accuracy before the core is photographed, geologically and geotechnically logged.

Geological logging is done using "Logchief" software linked to the Datashed SQL database that captures lithology, structure, mineralization, alteration, weathering, and material resistance / hardness. Core is routinely measured for bulk density (SG) with the oxide tested immediately after drilling to determine wet bulk density before being dried to determine dry bulk density. The method of density measurement used is the Jolly Method (see Section 10.7). Once the core has been bulk density tested and photographed, it is cut in half for assay. The remaining half is stored in purpose built, undercover racks at the site core yard.

amcconsultants.com

60

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

10.4Recovery

Core recovery is measured along with rock quality designation (RQD) in core run intervals. Average recoveries of core from all Tucano deposits is 94%. Both core recovery and RQD are recorded together in the drillhole database.

10.5Drilling orientation

Owing to the N-S strike of the Tucano system, drillholes are typically orientated to either Azimuth 090° or 270°, dependent on the dip of the lodes and / or availability of accessible sites. Dips of -50° to -90° can be achieved by the T60 Schramm RC rig whereas dips of -55° to -90° are possible with the diamond rigs. The vast majority of holes are orientated with dips of around -60°.

10.6Drillhole spacing

Grade control drilling is carried out on a nominal 10 mN x 12 mE spacing with infill to 10 mN x 6 mE in zones of lode mineralization. In-reserve pit drilling has been carried out on a spacing of between 20 m and 40 m within the plane of the mineralized structure. Deeper underground intercepts have been completed on a long-section spacing of between 40 m and 80 m.

10.7Sampling

1 m RC samples were obtained by an adjustable cone splitter attached to the base of the cyclone (1.5 kg to 6.0 kg) and were utilized for both lithology logging and assaying.

Diamond core is predominantly sampled at 1 m intervals, with some sampling on geological intervals (0.6 m to 1.4 m). Diamond core was used for structural, geotechnical, and density measurements as well as lithology logging and assaying. Density measurements were completed for both oxide and fresh whole core with the oxide densities calculated before and after drying to determine wet bulk density, dry bulk density, and moisture content.

The method of density measurement used was the Jolly Method. The weight of an intact 15 cm length of whole core is measured in air and again in water. The density is calculated by the formula SG = weight in air / (weight in air - weight in water). As oxide and transitional rock normally contains moisture, the sample is wrapped in plastic film and weighed while the core is still wet / moist, soon after being received from the drill rig. This enables a wet density to be calculated. The core is then oven dried, and the procedure repeated to attain the dry density.

amcconsultants.com

61

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

11Sample preparation, analyses, and security
11.1Sample preparation

Sample preparation is completed at the Tucano Mine sample preparation facility.

Core samples are dried at 105°C, crushed to -8 mm then to -2 mm and split to 0.9 kg to 1 kg before being pulverized to 1 mm. The 1 mm pulverized sample is quarter cut to between 200 g to 400 g before being pulverized to 95% passing 105 microns (μm). The final pulp is quartered again to achieve a sample of 100 g to 200 g and is sent to SGS laboratories in Belo Horizonte for fire assay. RC samples are dried at 140°C, crushed to -2 mm (if aggregated) and riffle split to 1 kg. The 1 kg sample is then pulverized to 1 mm and quarter cut to between 200 g and 400 g. This sample is then pulverized to 95% passing 105 μm and quarter cut to a 100 g to 200 g sample to send to SGS Geosol in Belo Horizonte.

11.2Sample security

Samples are securely sealed and stored onsite, until delivery to Macapá via the company contracted driver, who then also delivers the samples directly to airlines cargo dispatch facility for delivery to Belo Horizonte. Sample submission forms are sent with the samples to the laboratory and the laboratory emails a confirmation that the samples have been received along with a job number for tracking purpose.

11.3Sample analysis

Sample analysis is completed by both the site laboratory and an external laboratory (SGS Geosol Laboratorios Ltda in Belo Horizonte, Brazil). SGS Geosol Laboratorios has been accredited by ABS Quality Evaluations Inc and complies with the requirements for ISO 9001-2015. Further details of certifications for SGS Geosol Laboratorios can be found at their website: www.sgsgeosol.com.br.

Sample analysis is undertaken at both laboratories using a 30 g charge, fire assay with an AAS finish. For holes analysed at the Site laboratory, intervals that yield positive gold results have the corresponding pulverized sample sent to the external laboratory for analysis using the same methodology. Received results from the external laboratory then supersede the results of the Site Laboratory in the drillhole database and are used as an additional means to monitor site laboratory performance.

11.4Sample QAQC

Samples were sent to SGS Geosol in Belo Horizonte for analysis. Certified standards were inserted every 20th sample to assess the accuracy and methodology of the laboratory. Field duplicates were inserted every 20th sample of diamond core only to assess the repeatability and variability of the gold mineralization. The field duplicate sample used is the remaining half of the core from the same sample interval. No field duplicates are produced for the RC drilling which represents the majority for drilling completed. A blank standard was inserted at the start of every batch of approximately 150 samples. In addition, the contract laboratory’s SGS Geosol also carried out their own internal standards and laboratory duplicates for each lot. Results of the QAQC sampling were assessed on a batch by batch basis and were considered acceptable.

11.5QAQC data analysis

Assay QAQC data analysis for Beadell Brasil was undertaken by Maxwell Geoservices (Maxwell) of Fremantle, WA. Available QAQC data for gold assays from BDR’s various drilling programs within the date range of May 2012 to September 2017 is presented in the following sections.

amcconsultants.com

62

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

In early 2016 the grade control data, which was stored in Minesight Torque database, was integrated to the Maxwell Datashed (Datashed) database. The Minesight Torque database did not store the QC or Standards data for the grade control data and only some of the early batches were fully loaded to Datashed. The Datashed database is therefore incomplete for QC for the period prior to the start of 2016.

Notwithstanding the above, note that previous reports by Maxwell prior to 2015 have been reviewed with only minor issues identified.

The following Tucano Gold Project data has been assessed:

Standards: The standards assays provide a measure of relative analytical precision. Sample batches which fall outside specified tolerance ranges are flagged and investigated.
Laboratory Repeats (i.e. represents a second 50 g pulp sample taken from the first 200 g pulp).
Field Duplicates (i.e. represents a second 3 kg sample split taken from the original RC field sample interval. This sample is taken at the same time as the original sample).

A total of 8 datasets are available (4 deposit areas) for two separate laboratories, with gold assaying completed by both the site laboratory and external laboratories (SGS Geosol Laboratorios Ltda in Belo Horizonte). A total of 6 datasets are relevant to this report and are discussed here. A large number of standards are available for review and a total of 47 have been deleted from the dataset due to low usage (<10 times each).

11.6Statistical evaluation

The quality control data has been statistically evaluated, and summary plots have been produced for interpretation using the functions available in Maxwells QAQC Report software. The various available reports are summarized below.

11.7Onsite laboratory
11.7.1Tap AB grade control and resource dataset

The dataset contains a total of 245,690 drillhole samples from 4,124 batches. A total of 597 QC samples and 7,712 standards have been reviewed. Laboratory and field duplicate ratios are extremely low at 1:435 and 1:7,678 respectively. The ratio of client and laboratory inserted standards is also relatively low at 1:54 and 1:78 respectively.

A total of 85 separate client inserted standards have been recorded as included in the sample stream. Many appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 11 separate laboratory inserted standards have been recorded as included in the sample stream. A total of four have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 36 field duplicate checks are available results demonstrate equivalency between the first and second assays.

amcconsultants.com

63

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A total of 563 drill sample laboratory duplicates are available and demonstrate equivalency between the first and second assays.

No drill sample pulp checks are available. No drill sample laboratory repeats are available. No drill sample umpire checks have been undertaken.

Figure 11.1 shows a control chart for standard GE076 (outliers included) for the site laboratory for Tap AB.

Figure 11.1 Control chart for standard GE076

Source: BDR

11.7.2Tap C grade control and resource dataset

The dataset contains a total of 98,631 drillhole samples from 1,542 batches. A total of 26 QC samples and 1,554 standards have been reviewed. Laboratory duplicate ratios are extremely low at 1:3,794. There are no recorded field duplicate samples. The ratio of client and laboratory inserted standards is also relatively low at 1:107 and 1:157 respectively.

A total of 51 separate client inserted standards have been recorded as included in the sample stream. Many (more than eight in total) appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 5 separate laboratory inserted standards have been recorded as included in the sample stream. A total of two have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

amcconsultants.com

64

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A total of 26 drill sample laboratory duplicates are available and demonstrate equivalency between the first and second assays.

11.7.3Urucum grade control and resource dataset

The dataset contains a total of 133,831 drillhole samples from 2,164 batches. A total of 30 QC samples and 4,423 standards have been reviewed. Laboratory duplicate ratios are extremely low at 1:4,461. There are no field duplicate samples available. The ratio of client and laboratory inserted standards is also relatively low at 1:52 and 1:73 respectively.

A total of 58 separate client inserted standards have been recorded as included in the sample stream. Many appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of five separate laboratory inserted standards have been recorded as included in the sample stream. A total of four have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 29 drill sample laboratory duplicates are available and demonstrate equivalency between the first and second assays.

No drill sample pulp checks are available. No drill sample laboratory repeats are available. No drill sample umpire checks have been undertaken.

11.8SGS Belo Horizonte laboratory
11.8.1Tap AB grade control and resource dataset

The dataset contains a total of 48,732 drillhole samples from 812 batches. A total of 13,302 QC samples and 5,488 standards have been reviewed. Laboratory and field duplicate and laboratory repeat ratios are low at 1:4, 1:761, and 1:42 respectively. The field duplicate ratio is low. The ratio of client and laboratory inserted standards is acceptable at 1:23 and 1:15 respectively.

A total of 59 separate client inserted standards have been recorded as included in the sample stream. Many appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 41 separate laboratory inserted standards have been recorded as included in the sample stream. A number have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 24 field duplicate checks are available. Results do not demonstrate equivalency between the first and second assays. A total of 4 paired results are considered poor with differences of up to 167%. The dataset is not sufficiently large to make a meaningful conclusion.

A total of 121 drill sample laboratory duplicates are available and demonstrate equivalency between the first and second assays.

amcconsultants.com

65

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A total of 822 drill sample laboratory repeats are available and demonstrate equivalency between the first and second assays.

No drill sample pulp checks are available. No drill sample umpire checks have been undertaken.

11.8.2Tap C grade control and resource dataset

The dataset contains a total of 4,291 drillhole samples from 180 batches. A total of 328 QC samples and 1,256 standards have been reviewed. Laboratory duplicate ratios of 1:1 is unlikely and a database error is suspected. The laboratory repeat ratio is 1:13 which is acceptable. There are only 3 field duplicate samples. The ratio of client and laboratory inserted standards is acceptable at 1:12 and 1:5 respectively.

A total of 39 separate client inserted standards have been recorded as included in the sample stream. Many appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 36 separate laboratory inserted standards have been recorded as included in the sample stream. Many have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 53 drill sample laboratory duplicates are available and demonstrate equivalency between the first and second assays.

Only two field duplicate checks are available therefore no meaningful conclusion can be drawn. 237 drill sample laboratory repeats are available and demonstrate equivalency between the first and second assays.

No drill sample umpire checks have been undertaken. No drill sample pulp checks are available.

11.8.3Urucum grade control and resource dataset

The dataset contains a total of 19,174 drillhole samples from 326 batches. A total of 7,450 QC samples and 2,576 standards have been reviewed. Laboratory duplicate ratios (6,697) are acceptable at 1:3. There are 149 field duplicate samples available for a relatively low ratio of 1:129. The ratio of laboratory repeats (604) is a relatively low 1:32. The ratio of client and laboratory inserted standards is also relatively low at 1:23 and 1:11 respectively.

A total of 53 separate client inserted standards have been recorded as included in the sample stream. Many appear to have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Overall, despite some individual standards performing poorly, there does not appear to be a consistent pattern of bias in the dataset as a whole.

A total of 32 separate laboratory inserted standards have been recorded as included in the sample stream. Many have been used in small numbers and through limited date ranges and this can be considered less useful as reliable indicators of overall laboratory performance. Consistently with the client included standards, there does not appear to be a consistent pattern of bias in the dataset as a whole.

amcconsultants.com

66

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A total of 441 drill sample laboratory repeats are available and demonstrate equivalency between the first and second assays.

A total of 42 drill sample laboratory duplicates are available and demonstrate approximate equivalency between the first and second assays albeit this may be affected by a single high-grade outlier with poor repeatability.

A total of 149 drill sample field duplicates are available and demonstrate approximate equivalency between the first and second assays and again this appears be affected by several high-grade outlier with poor repeatability.

No drill sample pulp checks are available. No drill sample umpire checks have been undertaken.

Figure 11.2 shows a control chart for Standard G311-5 with outliers included from SGS Geosol date from Urucum.

Figure 11.2 Control chart for Standard G311-5

Source: BDR

11.9QP conclusions

The QP has reviewed the summary reports and Plots produced by Maxwell for the 2012 - 2017 dataset. Previous reports by Maxwell up to 2015 have also been reviewed with only minor issues noted (although not discussed here). The analysis has not been undertaken by the QP. The following are the conclusions and recommendations of the QP.

Standards, field duplicates and laboratory repeats have been reported for 8 datasets and two laboratories within the date range of 16 May 2012 to 8 September 2017.
Standards have been reported with charts displaying assays plotted by date and by instance and plotted according to whether they are client standards submitted by site, or laboratory standards included as part of laboratory QC processes.

amcconsultants.com

67

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

  

Several standards in the different reporting groups appear to have used only during relatively brief periods of time of 6 months or less and may not be reliable indicators of laboratory performance.
Overall, a number of standards appear to be been mislabelled having assays which are significantly different to the expected results. Some standards charts in each group show a negative or positive bias in the displayed results.
Field duplicates and laboratory repeats are included in the reports where available. Overall Field duplicates and laboratory repeats appear to be performing within expected limits.
Insufficient field duplicate assays have been undertaken over the period and it is recommended to increase the ratio of field duplicates to approximately 1:20. It is recommended to commence a program of field duplicate samples for RC drilling.
Despite the poor performance of certain standards, it is the QP’s opinion that there is no systematic bias present in the assay databases sufficient to make the grade estimates inaccurate. Overall, Certified Reference Materials (CRMs) have been inserted at a sufficient rate to monitor ongoing laboratory performance.
The inclusion of standards and various duplicates in the batches does not appear to follow a consistent pattern with strongly varying ratios in the proportion of the various QC samples to drill samples. It is recommended to undertake a thorough review and implementation of a more systematic QC program.
A very large number of different CRMs have been used by BDR since 2012. A substantial number of individual CRMs have been used only a few times or over a very limited date range and this provides only a very limited indication of the laboratories performance. It is recommended to rationalize the number of CRMs in use over any one period and ensure that an adequate grade range is maintained.

Based on this review work, the Qualified Person is of the opinion that the dataset provided is of an appropriate standard to use for resource estimation work.

In the opinion of the QP the sample preparation, security and analytical procedures are adequate, and the data is fit for purpose.

amcconsultants.com

68

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

12Data verification

The Qualified Person, Mr Brian Wolfe, visited the Tucano Gold Project in July 2015. Steps undertaken to verify the integrity of data used in this report include:

Field visits to the areas outlined in this report including the Tucano Gold Project permit and various gold deposits as discussed in the text.
Inspection of drill core and RC drill chips.
Inspection of AC, RC, and DC drilling activities, sampling, and logging procedures.
Review of BDR’s data collection, database management, and data validation procedures.
Review of the previous QA / QC reports for the project up to 2015.
Validation of drilling, geology, and assay database (including checks overlapping intervals, samples beyond hole depth, and other data irregularities).
Review of Maxwell Geoscience QA / QC reports and charts for standards, blanks, and duplicates.

Based on this review work, the Qualified Person is of the opinion that the dataset provided by BDR is of an appropriate standard to use for resource estimation work.

amcconsultants.com

69

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

13Mineral processing and metallurgical testing
13.1Summary

The existing Tucano gold processing plant was designed by Ausenco. After approximately four years of operation, an expansion was planned to install a 3 MW ball mill alongside the 7 MW single stage SAG mill, as well as a tailings thickener to accommodate the increasing proportion of harder sulphide ore being mined. The Expansion Project, which is in construction, is defined as follows:

An additional 6 MW ball mill to maintain throughput and obtain a finer product size of 80% < 75 μm at a higher proportion of sulphide ore.
A pre-leach thickener to allow both effective operation of the cyclones and adequate retention time in the CIL recovery plant.
Additional leach residence time.
Oxygen addition to CIL.
Lead nitrate addition to CIL.

The mill sizing calculations determined that a 4 MW mill should be adequate to grind the tonnages in the proposed mine plant to 80% < 75 μm; however, a larger 6 MW ball mill is recommended for the following reasons:

The selection of the smaller 4 MW ball mill assumes that the SAG and ball mills can operate continuously at 6.5 MW and close to 4 MW, respectively. This is difficult in practice. Selection of the larger 6 MW ball mill will allow optimization, and some “drift” of the respective SAG and ball mill power draws. It is likely that the actual optimum power draws for the SAG and ball mill will be closer to approximately 4 MW and 6 MW respectively.
A 6 MW ball mill is a better fit to work alongside the 6.5 MW SAG. It is very unusual in SAG / ball mill grinding installations that the ball mill has a smaller motor, than the SAG mill.
Future operations may decide to remove some of the current processing bottle-necks which limit production to 450 t/hr.
There is also some doubt as to the exact specific energy of all the sulphides. Selection of a 6 MW mill will ensure the treatment rate is maintained if harder sulphide ore is mined.
As gold prices increase, and power costs drop, the optimum grind calculation can decrease from 75 μm towards 53 μm, requiring more power.
Selection of a 6 MW mill allows some standardization of mill components with the existing Outotec SAG mill.

The cyclones are currently not operating effectively, which is affecting grind and recovery. The slurry has a high viscosity which is a function of the high percent solids that is required in the cyclone overflow to maintain adequate residence times in CIL. It is therefore recommended that a pre-leach thickener be installed.

At a throughput of 450 t/hr and a slurry density of 45% solids, a total volume of 17,200 m3 is required to provide a leach residence time of 24 hours. The existing CIL provides 15,400 m3; therefore, one additional leach tank, 15 m × 15 m is required. The new tank will be located ahead of the existing CIL tanks.

As of September 2018, commissioning of the ball mill was complete and the additional CIL tank and oxygen plant remains on track for late-October 2018 and early-November 2018, respectively.

amcconsultants.com

70

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

13.2Test work review

Three separate metallurgical test work programs have been carried out to date:

Amapari work program by NewGold Inc. (original heap leach).
Ausenco Feasibility Study program by Ausenco and Ammtec Limited (original mill).
Beadell FS program by BDR and their consultants, Ray Walton Consulting Inc. (RWC) and MPH Minerals Consultancy Ltd. (MPH) for the mill expansion.

The Amapari program by NewGold Inc. was focused on a heap leach operation and is not relevant to the grind and cyanidation process later adopted by BDR. The bulk of the test work to support the design of the original mill was carried out by Ausenco at Ammtec Limited (Ammtec). This was later supplemented by an operations review and other test work at SGS Geosol - Laboratórios Ltda (SGS Geosol) to support the design of the expansion. This was supervised by BDR. The latter two programs are summarized below.

13.3Ausenco FS metallurgical program

A detailed metallurgical test work program was conducted to support the initial feasibility study for the Tucano project. The program was supervised by Ausenco and was carried out by Ammtec in Perth, Western Australia, during the second half of 2010. It included test work to establish:

The comminution characteristics of four main ore type composite samples of Tap AB oxide, Tap AB sulphide, Urucum oxide and Urucum sulphide, and 15 variability samples.
The optimum grind size and cyanidation conditions for the four main ore type composite samples.
The gravity recovery response of the four main ore type composite samples.
The leach performance of 29 variability samples, including five Tap C oxide, two Tap C sulphide, and two Tap D oxide ores.
The leach performance of eight samples of ‘spent ore’ (heap leach tailings) and two samples of stockpiled low-grade ore.
Engineering data that included testing of oxygen uptake, carbon kinetics, slurry viscosity, and lime demand.
The performance of air / SO2 process and hydrogen peroxide (H2O2) for cyanide destruction.
The mineralogy of the four main ore type composites.

In addition, Ammtec prepared samples for dispatch to:

Coffey International Limited to establish physical characteristics of plant tailings.
ALS Environmental to establish geochemical characteristics of plant tailings.
FLSmidth Pty Ltd for thickening test work.
13.4BDR FS metallurgical program

In mid-2016 BDR, together with their consultants, RWC and MPH, reviewed the operation of the plant with specific emphasis on the low gold recovery and coarser grind that was being experienced at the time. Additional test work was performed, and the plant operating data was analysed and compared with the original mill design. It was concluded that certain critical areas required attention. An Expansion Project was defined as follows:

Additional grinding power provided by an additional ball mill.
A pre-leach thickener to allow both effective operation of the cyclones and adequate retention time in CIL.

 

amcconsultants.com

71

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Additional leach residence time.
Oxygen addition to CIL.
Lead nitrate addition to CIL.
13.5Testwork Process Development Ltd.

In mid-2016, samples were submitted to Testwork Process Development Ltd. for bottle roll testing as listed below:

Urucum sulphide
Urucum
Tap AB2 oxide
Tap AB3 sulphide
Tap AB2 transition
Spent ore

Leaching curves of gold recovery versus time were produced, with and without oxygen addition. The source of the samples was not recorded. Generally, the results were highly variable and not as expected, therefore an additional program at SGS Geosol was planned.

13.6SGS Geosol

In January 2017, a more definitive metallurgical test program was initiated. Ten composites were prepared, nine sulphides and one oxide, and were submitted to SGS Geosol for bottle roll testing as listed below:

Table 13.1 SGS Geosol samples

Metallurgical test composite Lode description Mine Pit
BDRMET1 AB1 Flat Sulphide Tap AB Tap AB1
BDRMET2 AB1 Trough Oxide Tap AB Tap AB1
BDRMET3 AB2 Sulphide Tap AB Tap AB2
BDRMET4 AB3 Sulphide Tap AB Tap AB3
BDRMET5 URS Sulphide Urucum Urucum South (URS)
BDRMET6 URCS Sulphide Urucum Urucum Central South (URCS)
BDRMET7 URCN SIB Sulphide Urucum Urucum Central North (URCN)
BDRMET8 URCN SCS Sulphide Urucum Urucum Central North (URCN)
BDRMET9 URN Sulphide Urucum Urucum North (URN)
BDRMET10 URN UG Sulphide Urucum Urucum North Underground (URN UG)

A summary of the selected drillhole intervals used to select the samples and sections showing the drillhole locations, within the proposed open pit, was provided. The metallurgical results are summarized in the following table.

amcconsultants.com

72

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Table 13.2 SGS Geosol bottle roll results

Metallurgical test composite Gold grade (g/t) 53 μm 75 μm 106 μm
BDRMET1 2.17 98.3 94.9 96.7
BDRMET2 2.41 96.6 96.1 97.6
BDRMET3 2.91 94.6 94.2 91.6
BDRMET4 2.81 97.3 95.7 97.6
BDRMET5 3.44 91.5 91.3 90.3
BDRMET6 2.48 90.4 93.0 91.0
BDRMET7 2.19 96.1 93.6 91.1
BDRMET8 7.14 97.6 95.7 91.9
BDRMET9 1.52 91.2 88.9 88.5
BDRMET10 5.71 96.5 95.7 93.2
Average 3.28 95.0 93.9 93.0

Leaching curves of gold recovery versus time were produced at various grind sizes. The data was analysed by BDR and their consultants and it was concluded that a residence time of 24 hours and a grind size of 80% < 75 μm was optimum. Although it can be seen that recoveries were higher at 53 μm than at 75 μm, the calculations carried out to determine the optimum grind, showed that net operating revenues at both grinds were similar. According to plant experience, recoveries fall significantly with grinds coarser than 80% < 106 μm.

13.7Conclusions and design criteria

The conclusions and design criteria from the two programs, i.e. the Ausenco and Ammtec FS and the Beadell FS, are described separately as follows.

13.7.1Ausenco and Ammtec FS program

Conclusions drawn from the Ausenco and Ammtec FS test work program are given below.

The oxide and sulphide ores have very dissimilar physical and comminution characteristics. The oxide ore has very low competency and low-to-average hardness, whereas the sulphide ores are competent to very competent and average to above average hardness. Co-processing of these ores is best suited to a SAG mill. A single-stage SAG mill is recommended for the first few years, when a high-oxide-low-sulphide blend is planned. A ball mill is to be added around Year 4 when the sulphide content of the blend is expected to rise.
Gravity test work in the laboratory showed a high recovery (35% to 56%) of gold by centrifugal gravity concentration and intensive cyanide of gravity concentrate. However, the overall gold recovery, including leaching of gravity tails, showed no recovery improvement in recovery over a whole ore leach. Therefore, the gravity circuit was not included in the processing plant design in order to reduce capital costs.
The Tucano ores are free-milling and are not “preg-robbing” and are amenable to gold extraction by conventional cyanidation.
As a group, the oxide ores respond in a similar manner to each other, giving very high recoveries (typically >95%) at a grind size of 80% < 75 µm, with moderate reagent consumptions of 0.55 kg/t NaCN and 5.5 kg/t lime (60% CaO).
The sulphide ores also have high recoveries, but typically 3% lower than oxide ores, at a grind size of 80% < 75 µm, and moderate reagent consumptions of 0.49 kg/t NaCN and 0.57 kg/t lime (60% CaO).

amcconsultants.com

73

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The ‘spent ore’ samples stockpiled from the previous heap leach operation had a recovery of 87% at a grind size of 80% < 75 µm, the low-grade ore stockpiled during the previous heap leach operation exhibited a recovery of 93.5% at a grind size of 80% < 75 µm.
Oxygen addition increases leach kinetics, primarily for the sulphide ores. The use of oxygen is recommended for the high sulphide ore blends planned for the fourth year of operation.
Pb(NO3)2 addition (at 100 g/t) appears to increase the gold leach kinetics for Tap AB oxide, such that extractions previously achieved at 48 hours are achieved at between 12 and 24 hours.
The planned Tucano ore blends both have thickener specific settling rates of 1.2 t/m2. The high sulphide blend requires 5 g/t to 7.5 g/t of flocculant and should achieve underflow solids concentration of 60% to 62% solids. By comparison, the high oxide blend would require twice as much flocculant and be expected to achieve an underflow solids concentration of 50% to 52% solids.
The air / SO2 process can be used to reduce cyanide in CIL tailings slurry to <3 ppm CNWAD and <25 ppm CNTOTAL.

The process design criteria recommended from this test work program by Ausenco are summarized in Table 13.3.

Table 13.3 Selected design criteria (Ausenco)

Parameter Unit Oxide Sulphide
Comminution      
Bond Rod Mill Work Index kWh/t 7.9 20.0
Bond Ball Mill Work Index kWh/t 11.3 16.8
Bond Abrasion Index kWh/t 0.03 0.43
JK Parameter A x b   192 34.9
Ore SG   3.57 3.27
Grind Size P80 µm 75 75
CIL      
CIL residence time h 24 24
Residual CNFREE Level mg/L 100 100
Tails thickening      
Specific Settling Rate t/m2.h 1.2 1.2
Underflow Density % w/w 50-52 60-62
Cyanide destruction      
Operating pH   8.5-9.0 8.5-9.0
Suggested residence time h 1 1
CIL Residual CNWAD Level mg/L 110 110
Tailings CNWAD mg/L <50 <50
Tailings CNWAD (target) mg/L <10 <10
Solution discharge CNTOTAL limit mg/L <0.2 <0.2
13.7.2Beadell FS program

The relevant studies and evaluations carried out by BDR and their consultants are summarized in detail in the Beadell 2016 FS. An alternative expansion strategy to the original Ausenco plan was recommended to maintain adequate throughput and recovery.

amcconsultants.com

74

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Conclusions drawn from the Plant Operation Review and the more recent SGS Geosol test work program, carried out as part of the Beadell FS, are given below.

The nominal throughput would be 3.6 Mtpa, 10,000 tpd, or 450 t/hr of predominantly sulphide ore, at a grind of 80% < 75 μm.
The new equipment would comprise a 6 MW ball mill, a 28 m diameter pre-leach thickener and an additional leach tank, located ahead of the existing CIL. An oxygen plant would also be included (see Figure 13.1).

Figure 13.1 Proposed Tucano expansion flow sheet

 

The design, sizing, and location of each new item of equipment are described below.

Ball mill

The SRK report, included in the Beadell FS, contains a description of the plant trials, mill sizing, and power requirement calculations. The conclusion was that to achieve the optimum grind of 80% < 75 μm, 7.1 kWh/t for oxide and 24.6 kWh/t for sulphide, would be required. The mill sizing calculations by SRK have determined that a 4 MW mill should be adequate to grind the tonnages in the proposed mine plant to 80% < 75 μm, however, a larger 6 MW ball mill is recommended, the reasons for which are outlined earlier.

Pre-leach thickener

In the current operation, the cyclones are operating inefficiently due to the high viscosity of the feed slurry. Operating experience is that the actual grind size currently being achieved is between 80% < 110 μm and 80% < 150 μm. The high viscosity is due to the high percent solids in the cyclone overflow which is required to maintain adequate residence times in CIL. It was therefore recommended by BDR and their consultants to install a pre-leach thickener. A 28 m diameter thickener was selected.

amcconsultants.com

75

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Thickening tests were done by Outotec during the Beadell FS. This thickener will provide two functions:

Allow the cyclones to be operated at a lower percent solid, and hence classify more effectively at the optimum grind of 75 μm.
Provide a slurry at a higher percent solid to the new leach tank and CIL, and hence maintain adequate residence times.

Additional leach tank

At a throughput of 450 t/hr, and a slurry density of 45% solids, a total volume of 17,200 m3 is required to provide a leach residence time of 24 hours. The existing CIL provides 15,400 m3, therefore, one additional tank, 15 m × 15 m, is required. The additional leach tank will be located ahead of the existing CIL tanks.

Reagents

The benefits of lead nitrate addition are shorter leach time and reduced cyanide consumption, particularly on the oxides ores, explained in Mike Hallewell’s report. Additions fall in the range of 100 g/t to 250 g/t as lead nitrate (PbNO3). A design figure of 150 g/t has been selected and a lead nitrate mixing, and dosing plant has already been installed.

RWC estimated oxygen consumption using benchmarks from other operations, and discussions with companies specializing in oxygenation. These figures were checked against the previous experience of personnel at Tucano. These benchmarks were also compared against typical specific aeration rates, adjusted for the improved mass transfer efficiency experienced with oxygen. A final check was made against an “oxygen uptake rate‟ measured using dissolved oxygen meters on slurries during a previous test work program. A plant capacity of 7.5 tpd of oxygen is recommended, i.e. approximately 0.75 kg of oxygen per tonne of slurry.

13.8Predicted recoveries

Using the recent data from the SGS Geosol testing and plant operating experience for sulphides, and previous data on oxide leaching from the Ausenco BFS, it is recommended that gold recoveries of 93.9% for sulphide and 97.0% for oxide are used in the economic evaluation. The numbers should be reduced by 0.6% to account for the soluble gold loss that occurs in CIL, i.e. 93.3% for sulphide and 96.4% for oxide.

amcconsultants.com

76

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

14Mineral Resource estimates

The Mineral Resources for the Property have been estimated by the following QPs Mr Brian Wolfe, Principal Resource Geologist of International Resource Solutions Pty Ltd, takes responsibility for the Tap AB and Urucum estimates of the open pit MIK models and Mr Marcelo Batelochi, Principal Resource Geologist of Soluções em Geologia e Mineração Ltda, takes responsibility for the remaining estimates.

The Mineral Resource estimates for the Tucano operation were reported in accordance with NI43-101 and the Canadian Institute of Mine Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves 2014 (CIM Standards).

The QPs are not aware of any known environmental, permitting, legal, title, taxation, socioeconomic, marketing, political, or other similar factors that could materially affect the stated Mineral Resource estimates.

The Tap AB Open Pit Mineral Resource has been revised as of 30 June 2017 based on new drilling completed in 2017, an updated US$1,500 optimized pit shell using Measured, Indicated, and Inferred resources and the 30 June 2017 topographic surface.

The Tap AB Underground Mineral Resource was revised as of 30 June 2017 by reporting the 31 December 2016 model below a US$1,500 optimized pit shell that was generated using the 30 June 2017 Tap AB Open Pit Mineral Resource model.

Models for the Tucano Gold Project that have not been revised since 31 December 2016 include the resources listed below. The reporting of Mineral Resources in relation to these models was released by BDR as a JORC compliant resource on the ASX dated 11 April 2017, "Ore Reserve and Mineral Resource Update". The reporting used reserve pit designs and optimized resource pit shells applicable at the time of reporting.

Urucum Open Pit
Urucum South Underground
Urucum North Underground
Tap AB Underground
Tap C
Duckhead
Urucum East

The reporting of Mineral Resources in relation to these models was released by BDR on the ASX dated 11 April 2017, "Ore Reserve and Mineral Resource Update". The details of this modelling are discussed below. These have been reviewed and are now reported compliant with the CIM standards.

Gold grade estimation for Tap AB and Urucum Open Pit resources was done using a combination of Multiple Indicator Kriging (MIK) and Ordinary Kriging (OK) and were constrained by grade shells derived from indicator kriging of drillhole gold grades.

Grade estimation was completed for Tap AB Underground, Urucum Underground, Tap C, Urucum East, and Duckhead using OK. OK estimates were constrained within manually interpreted mineralization wireframes and in the case of Duckhead, nested grade wireframes were used to tightly constrain the higher grades in the core of the Main Lode.

amcconsultants.com

77

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.1 Summary of estimated Mineral Resources (as of 30 June 2017)

Classification Tonnes (kt) Au grade (g/t) Contained Au metal (koz)
Measured 18,448 1.41 835
Indicated 22,293 1.96 1,405
Measured and Indicated 40,742 1.71 2,240
Inferred 16,351 2.19 1,150

Notes:

The June 2017 Tap AB UG Resource includes 173 kt at 4.68 g/t Au of Inferred Oxide within the Inferred Primary Category.
CIM Definition Standards (2014) were used for reporting the Mineral Resources.
Mr B. Wolfe, MAIG is the Qualified Person under NI 43-101 and takes responsibility for the Mineral Resource estimate for the Tap AB Open Pit and Urucum Open Pit Resource. Mr M. Batelochi, MAusImm (CP) is the Qualified Person under NI 43-101 and takes responsibility for all remaining resources.
Open pit Mineral Resources are constrained by an optimized pit shell at a gold price of US$1,500 oz. The cut-off grade (COG) applied to the open pit resources is 0.5 g/t Au. The COG applied to ore stockpiles is 0.5 g/t Au; with the exception of Marginal ore which has a grade COG 0.3 g/t Au.
The underground COG is 1.2 g/t Au.
Drilling results are up to the 30 June 2017 for the Tap AB Open Pit resource. For all other deposits, drilling results up to the 31 December 2016, excluding the Urucum North Underground resource which has drilling results up to September 2015.
Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
Mineral Resources are inclusive of their derived Mineral Reserves.
The numbers may not compute exactly due to rounding.
14.1Data used
14.1.1Drillhole database

The Mineral Resource estimation was based on the available exploration drillhole database which was compiled in-house by BDR.

The database includes samples from trenching, costean, auger, channel sampling, RAB, RC, and diamond drilling. RAB, RC, Auger, and diamond drilling have been included for the purpose of modelling and grade estimation at Tap AB and Urucum with all other data excluded from the estimates Tap AB and Urucum samples were composited to 3 m for the purpose of the June 2017 MIK Open Pit Resource estimate. Holes were sampled at 1 m intervals. The below table shows the breakdown of composites by hole type and total sample length.

A total of 5,836 drillholes were selected at Urucum, 179 drillholes at Urucum East, 5,357 at Tap AB, 8,995 at Tap C and 4,815 at Duckhead. The data type and number of drillholes in the resource area are shown in Table 14.2.

amcconsultants.com

78

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.2 Drillhole data used in the Open Pit Mineral Resource estimates

 

Deposit name Drillhole type # holes # composite assays Metres
Urucum MIK Open Pit. Auger 163 163 304
RAB 2,017 5,042 12,842
RC 3,356 22,168 59,506
Diamond 300 4,238 11,258
Tap AB MIK Open Pit RAB 0 0 0
RC 4,742 28,770 77,581
Diamond 615 6,142 16,200
Tap C OK Open Pit RAB 2,098 4,628 8,204
RC 2,346 19,928 36,701
Auger 689 1,250 2,156
Trench 3,691 37,600 71,602
Channel 38 292 550
Diamond 133 1,930 3,478
Duckhead RAB 391 983 1,805
RC 1,010 6,661 12,362
Auger 108 174 285
Channel 14 93 171
Trench 33 310 591
Diamond 66 415 770
Urucum East Auger 71 176 174
RC 8 51 51
Diamond 100 669 665

Note: Urucum and Tap AB Open Pit Resources were composited to 3 m, Tap C and Duckhead composited to 2 m, and Urucum East to 1 m.

Plan view of the drilling for Urucum and Tap AB are shown in Figure 14.1 below.

amcconsultants.com

79

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.1 Plan view of drilling Urucum (left) and Tap AB (right)

Source: B. Wolfe (International Resource Solutions Pty Ltd)

14.1.2Bulk density

A total of 113,629 density measurements of diamond core were collected from the property. The collection of bulk density measurements is described in Section 10. The spacing and distribution of the measurements allows for density to be estimated throughout the block models.

For the Urucum deposit bulk density was estimated using OK and Nearest Neighbour (NN). For the Tap AB deposit bulk density was estimated using OK. For the Tap C deposit bulk density was estimated using Inverse Power Distance (IPD). For the Duckhead deposit bulk density was estimated using NN.

Table 14.3 shows the number of density samples collected at each deposit by weathering type.

amcconsultants.com

80

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.3 Summary of bulk density measurements by weathering type

  # samples oxide # samples transitional # samples fresh # samples total
Urucum 414   37,583 37,998
Tap AB 2,755   30,347 33,102
Tap C 7,167 132 30,714 38,013
Duckhead 739   3,777 4,516

Table 14.4 to Table 14.7 compare the original density measurements with the results from the block model estimate by lithology for each deposit. Blocks are in general agreement with the original measurements.

Table 14.4 Urucum: Comparative statistics of bulk density

  Measured density Estimated density
Lithology Oxide t/m3 Fresh t/m3 Oxide t/m3 Fresh t/m3
Colluvium 1.90-2.00   1.60  
BIF 2.08 3.30 2.17 3.34
Carbonate 2.27 3.10 2.22 3.10
Schist 2.03 2.80 2.17 2.90
Pegmatite 2.27 2.77 1.79 2.79
Amphibolite     1.79 3.20

Table 14.5 Tap AB: Comparative statistics of bulk density

  Measured density Estimated density
Lithology Oxide t/m3 Fresh t/m3 Oxide t/m3 Fresh t/m3
Colluvium 1.89 - 1.80 -
BIF 2.76 3.35 2.23 3.34
Carbonate 2.27 3.11 1.90 3.10
Schist 1.99 2.89 1.92 2.90
Pegmatite 2.27 2.79 2.06 2.79
Amphibolite 1.76 3.39 1.93 3.20

Table 14.6 Tap C: Comparative statistics of bulk density

  Measured density Estimated density
Lithology Oxide t/m3 Trans t/m3 Fresh t/m3 Oxide t/m3 Trans t/m3 Fresh t/m3
Colluvium and soil 1.75     1.92    
Amphibolites / diabases 1.85 2.89 3.17 2.22 2.79 2.98
Banded iron formation 2.32 2.17 3.39 2.50 3.23 3.36
Calcsilicates 1.95 2.20 3.13 1.76 2.37 3.19
Cabonates / hidrot. alter. 2.02 3.13 3.06 2.01 2.83 3.11
Schists and quartzites 2.40 2.70 2.79 1.79 2.61 2.76
Iron formation 1.77 3.13 3.34 2.47 3.08 3.32
Granites and pegmatites     2.78 2.03 0 2.87

 

amcconsultants.com

81

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Table 14.7 Duckhead: Comparative statistics of bulk density

Lithology Measured density Estimated density
Description Oxide g/cm3 Fresh g/cm3 Oxide g/cm3 Fresh g/cm3
Schist 2.74 2.85 2.59 2.84
Carbonate 2.37 3.09 2.77 3.07
BIF 2.91 3.19 2.95 3.05
Amphibolites 2.99 3.04 3.00 3.04
Outer schists amphibolite 3.00 3.01 2.98 3.03
14.2Interpretation and modelling

There are four deposits, Urucum, Tap C, Tap AB, and Duckhead.

For modelling purposes Urucum is further subdivided into Urucum North open pit and underground, Urucum South open pit and underground, and East Urucum models. Tap AB is also split into open pit and underground models. Tap C is also divided into two areas: Tap C (other) and Tap C (C3N and C3W).

14.2.1Geological interpretation
14.2.1.1Tap AB and Urucum

Based on grade information and geological observations, colluvium and oxidation boundaries have been interpreted and wireframes modelled to constrain resource estimation. Interpretation and digitizing of all constraining boundaries has been undertaken on cross sections orientated at 90º (drill line orientation). The resultant digitized boundaries have been used to construct wireframe surfaces or solids defining the three-dimensional geometry of each interpreted feature.

In a similar fashion, geological logging of drill core and RC chips has been input into the construction of lithological wireframes for the project. At Urucum and Urucum East, modelled lithologies comprise pegmatites and granites, BIF, schist, and carbonate rocks. At Tap AB an additional lithology amphibolite has also been modelled. Schematic cross sections are presented in Figure 14.2 and Figure 14.3. Note topography is pre-mining topography.

amcconsultants.com

82

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.2 Urucum Gold Deposit cross section displaying geology and coded block model

Note: Section 99,050 mN

Source: B. Wolfe (International Resource Solutions Pty Ltd)

 

amcconsultants.com

83

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.3 Tap AB Gold Deposit cross section displaying geology and coded block model

Note: Section 93,930 mN

Source: B. Wolfe (International Resource Solutions Pty Ltd)

14.2.1.2Tap C

Although reported as one Mineral Resource, the geological model was developed differently in different zones. For the purpose of geological domaining the area is divided into the C3N and C3W zones and “other”.

For C3N and C3W zones, the lithological domains were manually modelled based on 10 m space sections. Outside of these zones, only the pegmatite that cross cuts the mineralization was modelled using a wireframe solid. The remaining lithologies were estimated using a NN approach.

Figure 14.5 shows the lithological solids as used for the C3N and C3W areas.

 

 

amcconsultants.com

84

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.4 Isometric view of Tap C lithology solids

Note: Tap C Model Area; Green = Schist, Brown = BIF, Blue = Carbonates, Red = Pegmatites. As used for areas C3N and C3w.

Source: BDR.

14.2.1.3   Duckhead

 

The Duckhead geological model was rebuilt on 10 m spaced oblique NE-SW sections cut oblique to the strike of the stratigraphy. The modelling approach used was the same as Tap AB and Urucum. Figure 14.5 below shows the main banded iron unit with internal carbonates, schists, and amphibolites.

 

 

amcconsultants.com

85

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.5 Plan view of Duckhead showing the modelled lithological units

Note: Large Green Area= Schist, Minor Green Areas = Amphibolites, Brown = BIF, Blue = Carbonates.

Source: BDR.

14.2.2Mineralization interpretation

The models were estimated by either OK or a combination of MIK and OK. As such mineralization domains were built based on wireframing on a sectional and plan basis as well as being generated by grade shell via indicator kriging at a selective cut-off grade (COG).

14.2.2.1Tap AB and Urucum Open pit model

The style of mineralization is discussed in Section 7.3. Typically, for many deposits of its type, the mineralization often presents as generally somewhat discontinuous and irregularly distributed on the scale of approximately 50 m to 100 m. Sectional views, even 30 m apart, demonstrate variability in grade, thickness, and orientation of gold mineralization.

This commonly makes the traditional approach of wireframing on a sectional and plan basis somewhat difficult with multiple plausible geometrical solutions often existing.

To establish appropriate grade continuity, the mineralization models for the Tap AB and Urucum Open Pit were therefore based upon a nominal 0.3 ppm Au indicator mineralization shell estimated using 3 m unconstrained downhole composites. This interpretation is designed to capture the broad mineralization halo that encompasses the geological vein system and is not intended to constrain individual veins or vein clusters. As the main grade estimation technique is MIK with change of support technique, this type of mineralization constraint is deemed appropriate.

The mineralization grade shell was generated by grade shell via indicator kriging at a single COG, 0.3 g/t Au. Grade estimation was into block models with cell dimensions of 2 mE × 2 mN × 2 mRL. Grade shell triangulations were then generated by constraining the block model at a 35% probability cut-off for Tap AB and a 31% probability cut-off for Urucum. The probability cut-offs may be considered somewhat subjective and may seem arbitrary, however were selected based on extensive review of a range of probability cut-off levels. The selected probability shells are considered optimal to capture the observed continuity and tenor of mineralization while excluding obvious low-grade material. Grade shells were reviewed in multiple orientations and in plan and section view prior to being accepted for grade estimation and block modelling purposes.

amcconsultants.com

86

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Mineralization estimation domains were thus defined with further sub-division being differentiated on the basis of orientation, flexures in the shear and tenor of gold grade. In the case of Tap AB, a total of seven estimation domains have been defined.

An isometric SE view of the estimation domains is presented in Figure 14.6.

Figure 14.6 Tap AB Gold Deposit isometric SE view

Source: B. Wolfe (International Resource Solutions Pty Ltd).

At Urucum a total of ten estimation domains have been defined with six minor flat lying domains relating to bodies of colluvium having been generated by manual wireframing and four major steeply orientated domains generated via grade shell estimate as previously described. Generalized relationships between the mineralized domains are presented in Figure 14.7.

amcconsultants.com

87

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.7 Urucum Gold Deposit isometric SE view

Source: B. Wolfe (International Resource Solutions Pty Ltd).

14.2.2.2Tap AB and Urucum Underground model

Both the Tap AB and Urucum Underground models had manually constructed wireframes built on 10 m vertical E-W sections using both drillhole geology and assay grades to drive the interpretation and digitization.

For the Tap AB underground, 21 mineralization domains were built for the purpose of estimating the underground Mineral Resource (Figure 14.8). The digitizing was based on a nominal 1.4 g/t Au COG for drillholes below a 2016 US$1,500 optimized pit shell.

amcconsultants.com

88

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.8 Oblique view of the Tap AB constructed mineralization wireframes

Source: BDR.

For the Urucum North Underground model eight principal mineralization domains were constructed north of 99,400 mN for the purpose of the Mineral Resource estimate. In addition to interpreting these mineralization domains as major planar structures, the internal high-grade shoots within these lodes were also modelled based on detailed long section analysis and field observation of structures in the pit (Figure 14.9). These shoots were modelled as separate domains in the OK estimation process and in total 24 domains were used in the OK estimation. All wireframes were manually built by digitizing on 10 m sections and at a nominal COG of 1.4 g/t Au.

amcconsultants.com

89

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.9 Cross section of all Urucum North Underground domains

 

Notes: Section 99,800 mN.

Source: BDR.

14.2.2.3Urucum North and South Underground model

For the Urucum South Underground block model, 70 mineralization domains were constructed and updated with new drillhole results as of March 2016. Lodes south of 99,400 mN were modelled manually on 10 m section using a nominal COG of 1.4 g/t Au below a 2016 US$1,500 optimized pit shell.

North of 99,400 mN, for the Urucum North underground block model (reference: urucum_ug_ resource2015_v17.mdl). Figure 14.10 below shows the underground resource Urucum North and Urucum South lode wireframes and the divisor at 99,400 mN.

amcconsultants.com

90

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.10 Long section view of Urucum showing the underground mineralization domains

 

Note: red line shows the divisor between Urucum South and Urucum North at 99,400 mN.

Source: BDR.

14.2.2.4Urucum East model

The Urucum East deposit consists of two mineralization domains. The first domain is the bedrock mineralization that is cross cut by pegmatite dykes. The second domain is the mineralized colluvium.

Where the pegmatite partially crosses the mineralization wireframe, this is deemed to have introduced zero Au grade. No separate colluvium mineralized envelope was created for gold mineralization within the colluvium but rather the entire lithological unit for the colluvium was used in the gold estimation.

14.2.2.5Tap C model

For the Tap C deposit 25 mineralization domains were manually digitized and wireframed on 10 m sections using a nominal 0.3 g/t Au COG (Figure 14.11). A low-grade envelope was also constructed using a 0.1 g/t Au envelope using Implicit Modeller in Minesight.

amcconsultants.com

91

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.11 Tap C gold mineralization domains - oblique view

Source: BDR.

14.2.2.6Duckhead model

For the Duckhead deposit, 24 mineralization domains were modelled and were also split into oxide and sulphide sub domains for gold grade estimation where sufficient data existed. The modelling for Duckhead covers the main Duckhead pit and also the surrounding smaller deposits as shown in Figure 14.12. Due to the extremely high grades in Duckhead it was necessary to create the model using nested grade shells, one inside the other, to restrict the influence of very high grades in the core of the deposit.

The following nominal COGs were used to drive the digitization of the nested grade shells:

Duckhead Main Lode Extreme Grade Core: >50 g/t Au = Lode 1.
Duckhead Main Lode High Grade Envelope: >2 g/t Au = Lode 2.
Duckhead Main Lode Low Grade Envelope: >0.3 g/t Au = Lode 3.
Duckhead Hangingwall Lode High Grade Envelope: >2 g/t Au = Lode 4.
Duckhead Hangingwall Lode High Grade Envelope: >0.3 g/t Au = Lode 4.

The rest of the lodes were modelled using a 0.3 g/t Au COG.

amcconsultants.com

92

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 14.12 Mineralized wireframes of Duckhead and surrounding deposits

Source: BDR

14.3Compositing

At Tap AB and Urucum, drillhole samples were flagged with the relevant mineralization wireframes, indicator grade shells, topographical surfaces, and the oxidation wireframes described in previous sections. Coding was undertaken on the basis that if the individual sample centroid fell within the grade shell boundary it was coded as within the grade shell. Each domain has been assigned a unique numerical code to allow the application of hard boundary domains if required during grade estimation.

The drillhole database coded within each grade shell or mineralization wireframe was then composited as a means of achieving a uniform sample support. It should be noted, however, that equalizing sample length is not the only criteria for standardizing sample support. Factors such as angle of intersection of the sampling to mineralization, sample type and diameters, drilling conditions, recovery, sampling / sub-sampling practices and laboratory practices all affect the ‘support’ of a sample. Exploration / mining databases which contain multiple sample types and / or sources of data provide challenges in generating composite data with equalized sample support, and uniform support is frequently difficult to achieve.

After consideration of relevant factors relating to geological setting and mining, including likely mining selectivity and bench / flitch height, a regular 3 m run length (down hole) composite was selected as the most appropriate composite interval to equalize the sample support for the Tap AB and Urucum Deposits. Compositing was broken when the routine encountered a change in flagging (grade shell boundary) and composites with residual intervals of less than 1.2 m were retained by addition to the previous composite resulting in a composite file containing composites between 1.2 m and 4.2 m in length.

amcconsultants.com

93

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

At Tap C and Duckhead, downhole composites of 2 m were created inside the mineralization solids and flagged by lode code. Composites with a majority length inside the cross-cutting pegmatite solid were removed to minimize internal dilution. A minimum composite length was set at 0.95 m. Comparison between total sample length and the mean gold grade of flagged and composited data showed negligible bias and reduction in metal content.

The Urucum North Underground estimate used a 1 m composite length. The 31 December 2016 Underground Resources for both Tap AB and Urucum South both used a 3 m composite length keeping consistent with the composite length used in the Open Pit Resource estimates for these deposits. Investigation into composite lengths showed no expressive bias going from a 1 m to 3 m composite length.

14.4Statistical analysis
14.4.1Tap AB Open Pit model
14.4.1.1Descriptive statistics

The composites flagged as described in the previous section were used for subsequent statistical, geostatistical, and grade estimation investigations.

Summary descriptive statistics were generated for all domains (Table 14.8). The grade distributions are typical for gold deposits of this style and show a positive skew or near lognormal behaviour. The coefficient of variation (CV) is moderately high, consistent with the presence of high outlier grades that potentially require cutting (capping) for grade estimation. Table 14.8 shows statistics for composited data and for data following capping outlier grades.

Table 14.8 Tap AB Gold Deposit - Open Pit model summary statistics gold (g/t)

Composited
Domain 10 101 102 110 200 1,000 2,000 3,000
Count 4,096 9,449 189 379 5,833 2,194 4,845 7,927
Minimum 0.001 0.001 0.004 0.019 0.001 0.001 0.001 0.001
Maximum 95.1 652.45 9.873 68.837 327.48 551.957 106.94 79.283
Mean 0.541 1.217 0.762 1.341 1.426 4.992 1.302 1.559
SD 2.257 7.177 1.049 4.199 6.290 20.509 3.839 3.561
CV 4.171 5.897 1.376 3.132 4.412 4.108 2.948 2.284
Capped
Domain 10 101 102 110 200 1,000 2,000 3,000
Count 4,096 9,449 189 379 5,833 2,194 4,845 7,927
Minimum 0.001 0.001 0.004 0.019 0.001 0.001 0.001 0.001
Maximum 20 24 9.873 8 30 100 30 36
Mean 0.506 1.121 0.762 1.038 1.311 4.421 1.230 1.536
SD 1.427 2.010 1.049 1.511 2.895 13.619 2.759 3.236
CV 2.819 1.793 1.376 1.456 2.207 3.081 2.242 2.107

SD = Standard Deviation; CV = Coefficient of Variation

amcconsultants.com

94

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.1.2High grade outlier analysis

MIK has been selected as an appropriate method to estimate the gold grades for the Tap AB Gold Deposit. However, the grade datasets for the various estimation domains are characterized by moderately high CV values, indicating that high grade values may contribute significantly to the mean grades reported for the various datasets.

It should be noted that while gold grades are not cut or capped for the purposes of MIK estimation the use of cut grades is often employed for variography and the change of support process. As MIK estimates are essentially a series of OK estimates applied to the binary transformation of a series of indicator cut-offs, high grade cutting will have no effect on the resultant MIK estimate unless the high-grade cut is lower than the chosen upper indicator cut-off and this scenario would be considered highly sub-optimal in the context of MIK estimation.

The effects of the highest grade composites on the mean grade and standard deviation (SD) of the gold dataset for each of the estimation domains have been investigated by compiling and reviewing statistical plots (histograms and probability plots). The resultant plots were reviewed together with probability plots of the sample populations and an upper cut for each dataset was chosen coinciding with a pronounced inflection or increase in the variance of the data. A list of the determined upper cuts applied, and their impact on the mean grades of the datasets is provided in Table 14.8. Composite data was viewed in 3D to determine the clustering or otherwise of these highest grades observed in each domain to assess the appropriateness of the high-grade cut. Clustering of the highest grades in one or more areas may indicate that the grades do not require to be cut and need to be dealt with in a different way.

14.4.1.3MIK cut-offs and indicator class statistics

 

Indicator Kriging cut-offs or indicator bins were selected for each domain to be estimated by MIK. Cut-offs were based upon population distributions and metal proportions above and below the mean composite value of the proposed cut-off bins. Conditional statistics for data for the two largest domains to be estimated by MIK are listed in Table 14.9. A total of 17 cut-offs were applied to each domain for estimation via MIK. Top cuts have not been applied for the purposes of conditional statistics calculation.

amcconsultants.com

95

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.9 Tap AB Gold Deposit - Open Pit Resource indicator class statistics

Domain
Zone 101 Zone 3000

Probability

threshold

Grade threshold

Au (g/t)

Class mean

Au (g/t)

Probability

threshold

Grade threshold

Au (g/t)

Class mean

Au (g/t)

0.225 0.3 0.1667 0.217 0.3 0.1573
0.361 0.4 0.3461 0.355 0.4 0.345
0.469 0.5 0.4442 0.452 0.5 0.4442
0.544 0.6 0.5463 0.522 0.6 0.5453
0.626 0.75 0.6672 0.578 0.7 0.6462
0.688 0.9 0.8224 0.637 0.85 0.768
0.746 1.1 0.9892 0.683 1 0.9199
0.788 1.3 1.191 0.733 1.2 1.0816
0.827 1.55 1.4231 0.783 1.5 1.337
0.854 1.8 1.6698 0.817 1.8 1.6326
0.881 2.1 1.9481 0.843 2.2 1.9846
0.906 2.5 2.2952 0.875 2.7 2.4381
0.924 2.9 2.6887 0.903 3.5 3.1036
0.941 3.5 3.1618 0.927 4.5 4.0061
0.960 4.5 3.9364 0.949 6 5.2296
0.976 6 5.1924 0.968 8.5 7.1726
0.992 11 7.7969 0.987 15 10.9904
Max Max 17.6222 Max Max 23.6843

Note: statistics are shown for the two largest domains only.

14.4.2Urucum Open Pit model
14.4.2.1Descriptive statistics

Summary descriptive statistics were generated for all domains and the statistical results for all domains are shown in Table 14.10. The grade distributions are typical for gold deposits of this style and show a positive skew or near lognormal behaviour. The CV is moderate to high, consistent with the presence of high outlier grades that potentially require cutting (capping) for grade estimation. This is evident in the domains selected for estimation via MIK.

14.4.2.2High grade outlier analysis

MIK has been selected as an appropriate method to estimate the gold grades for the main estimation domains of the Urucum Gold Deposit. However, the grade datasets for some of the estimation domains are characterized by moderately high CV values, indicating that high grade values may contribute significantly to the mean grades reported for the various datasets.

The effects of the highest grade composites on the mean grade and standard deviation of the gold dataset for each of the estimation domains have been investigated by compiling and reviewing statistical plots (histograms and probability plots). The resultant plots were reviewed together with probability plots of the sample populations and an upper cut for each dataset was chosen coinciding with a pronounced inflection or increase in the variance of the data. A list of the determined upper cuts applied and their impact on the mean grades of the domains is provided in Table 14.10.

Composite data was viewed in 3D to determine the clustering or otherwise of these highest grades observed in each domain to assess the appropriateness of the high-grade cut. Clustering of the highest grades in one or more areas may indicate that the grades do not require to be cut and need to be dealt with in a different way.

amcconsultants.com

96

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.2.3MIK cut-offs and indicator class statistics

Indicator Kriging cut-offs or indicator bins were selected for each domain to be estimated by MIK. Cut-offs were based upon population distributions and metal proportions above and below the mean composite value of the proposed cut-off bins. Conditional statistics for data within each domain to be estimated by MIK are listed in Table 14.11. A total of 17 cut-offs were applied to each Domain for estimation via MIK. Top cuts have not been applied for the purposes of conditional statistics calculation. Note that due to a paucity of samples in Domain 300, the conditional statistics for Domain 400 have been adopted for the purposes of change of support process.

Table 14.10 Urucum Gold Deposit - Open Pit model; summary statistics gold (g/t)

Composite
Domain 100 200 300 400 510 520 530 540 550 700
Count 2,195 14,676 179 7,389 2,667 458 203 596 87 3,161
Minimum 0.001 0.001 0.001 0.001 0.001 0.004 0.01 0.04 0.013 0.001
Maximum 21.907 82.867 32.666 59.99 15.48 7.667 2.91 5.89 5.567 20.584
Mean 1.073 1.225 1.684 1.053 1.094 0.719 0.611 0.905 1.020 1.181
SD 1.656 2.408 3.468 2.221 1.129 0.698 0.442 0.597 0.981 1.403
CV 1.543 1.966 2.059 2.110 1.032 0.970 0.725 0.660 0.961 1.188
Capped
Domain 100 200 300 400 510 520 530 540 550 700
Count 2,195 14,676 179 7,389 2,667 458 203 596 87 3,161
Minimum 0.001 0.001 0.001 0.001 0.001 0.004 0.01 0.04 0.013 0.001
Maximum 15 20 20 20 12 7.667 2.91 5.89 5.567 13
Mean 1.069 1.201 1.613 1.025 1.093 0.719 0.611 0.905 1.020 1.173
SD 1.611 2.031 2.921 1.794 1.114 0.698 0.442 0.597 0.981 1.317
CV 1.507 1.690 1.810 1.751 1.019 0.970 0.725 0.660 0.961 1.123

SD = Standard Deviation; CV = Coefficient of Variation

amcconsultants.com

97

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.11 Urucum Gold Deposit - Open Pit model indicator class statistics (selective)

Domain
Zone 400 Zone 200

Probability

threshold

Grade threshold

Au (g/t)

Class mean

Au (g/t)

Probability

threshold

Grade threshold

Au (g/t)

Class mean

Au (g/t)

0.242 0.3 0.1726 0.245 0.3 0.1494
0.371 0.4 0.3480 0.373 0.4 0.3450
0.480 0.5 0.4459 0.468 0.5 0.4466
0.560 0.6 0.5482 0.541 0.6 0.5403
0.623 0.7 0.6470 0.600 0.7 0.6456
0.667 0.8 0.7447 0.642 0.8 0.7511
0.709 0.9 0.8447 0.678 0.9 0.8497
0.742 1 0.9472 0.706 1.0 0.9474
0.781 1.15 1.0655 0.741 1.15 1.0740
0.811 1.3 1.2204 0.771 1.3 1.2279
0.840 1.5 1.3927 0.785 1.5 1.3957
0.863 1.7 1.5959 0.813 1.7 1.5889
0.893 2 1.8436 0.842 2.0 1.8474
0.919 2.4 2.1820 0.871 2.4 2.1520
0.939 2.9 2.6449 0.901 2.9 2.6419
0.959 3.8 3.2882 0.931 3.8 3.3125
0.978 6 4.7374 0.968 6 4.8105
Max Max 12.1008 Max Max 9.5410

Note: statistics are shown for the two largest domains only.

14.4.3Tap AB Underground model
14.4.3.1Descriptive statistics

Raw statistics of each lode split by oxide and fresh surfaces were generated. The results of this statistical study have shown high variability, some characteristics common in gold deposits with coefficients of variation often high due to dilution caused by internal waste within the lodes. As a consequence of the high variability shown in the gold distribution, a large part of the gold metal is contained in the tail of the distribution and required analysis and treatment of the outliers in the composite dataset. Table 14.12 below shows the raw and composited data for the domains.

 

amcconsultants.com

98

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.12 Tap AB Underground model; statistics by domain

Raw
Domain Count Minimum Maximum Mean SE mean SD CV
LODE10 15,530 0.005 1877.3 1.18 0.12 15.27 12.89
LODE11A 634 0.005 24.94 1.36 0.11 2.71 1.99
LODE11B 1,650 0.01 48.36 1.43 0.07 2.72 1.91
LODE12A 520 0.005 40.63 0.93 0.11 2.48 2.68
LODE12B 286 0.005 8.75 0.58 0.06 0.94 1.63
LODE12C 635 0.005 16.34 0.95 0.06 1.53 1.60
LODE12D 1,210 0.005 33.34 1.44 0.09 3.08 2.14
LODE14A 1,805 0.005 81.38 3.19 0.16 6.65 2.08
LODE14B 2,751 0.005 394.44 5.35 0.45 23.76 4.44
LODE1A 19,588 0.005 498.78 1.58 0.04 6.21 3.93
LODE1B 239 0.010 12.87 1.11 0.12 1.88 1.69
LODE1C 596 0.005 36.64 1.45 0.12 2.94 2.03
LODE3 1,560 0.005 109.53 2.47 0.16 6.43 2.61
LODE4 3,491 0.005 498.78 1.80 0.18 10.78 5.98
LODE5 2,552 0.005 145.60 2.95 0.15 7.82 2.65
LODE6 508 0.005 41.64 0.83 0.11 2.52 3.04
LODE9A 6,165 0.005 143.27 1.30 0.04 3.47 2.66
LODE9B 308 0.010 8.84 0.62 0.04 0.78 1.27
MLODE2A 2,629 0.005 109.07 0.74 0.06 3.22 4.32
MLODE2B 1,166 0.005 33.15 1.03 0.07 2.47 2.39
MLODE2C 258 0.005 20.20 0.91 0.13 2.06 2.25
Composite
Domain Count Minimum Maximum Mean SE mean SD CV
LODE10 9,693 0.005 527.39 1.16 0.06 6.02 5.18
LODE11A 417 0.005 21.02 1.31 0.12 2.36 1.80
LODE11B 804 0.005 20.43 1.30 0.07 1.94 1.49
LODE12A 593 0.005 15.97 1.01 0.07 1.72 1.71
LODE12B 98 0.044 4.80 0.66 0.08 0.80 1.20
LODE12C 272 0.039 8.37 0.98 0.07 1.18 1.20
LODE12D 549 0.005 28.16 1.62 0.14 3.30 2.04
LODE14A 827 0.005 37.91 2.79 0.16 4.62 1.66
LODE14B 2,317 0.005 547.96 5.75 0.43 20.45 3.55
LODE1A 43 0.018 11.35 1.23 0.27 1.77 1.44
LODE1B 97 0.005 7.05 1.15 0.13 1.31 1.14
LODE1C 223 0.01 15.48 1.41 0.12 1.83 1.29
LODE3 684 0.005 67.89 2.39 0.17 4.49 1.88
LODE4 2,909 0.005 327.53 1.95 0.16 8.67 4.45
LODE5 1,010 0.005 53.80 2.91 0.18 5.75 1.98
LODE6 538 0.005 16.66 1.04 0.08 1.80 1.73
LODE9A 3,182 0.005 74.20 1.28 0.05 2.70 2.11
LODE9B 171 0.041 7.71 0.76 0.07 0.86 1.13
MLODE2A 1,820 0.005 37.86 0.86 0.04 1.89 2.20
MLODE2B 627 0.005 28.64 1.09 0.09 2.18 2.00
MLODE2C 145 0.005 13.14 1.16 0.17 2.01 1.73

SD = Standard Deviation; CV = Coefficient of Variation

amcconsultants.com

99

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.3.2High grade outlier analysis

Three metre composite samples have had a top cut applied for each lode based on the outlier shown in logarithmic histogram and log probability plots. Grades were cut to within the 98th to 100th percentile and in the case of lodes with less than 100 samples there was no top cut applied however the range of estimation for the outliers was reduced to 20 m.

Table 14.3 shows the capping by domains.

Table 14.13 Tap AB Underground Resource; 3 m composite top cut capping by domain

Domain

Domain is split into separate Oxide

and Sulphide Domains

Au capping (g/t)
lode10 Yes 9
lode11a No 9
lode11b No 9
lode6 Yes 9
lode12a Yes 7
lode12b No No
lode12c No 5
lode12d Yes 15
lode14a No 20
lode14b Yes 80
lode1a No 3
lode1b Yes No
lode3 Yes 20
lode5 Yes 25
lode4 Yes 18
lode9a Yes 10
lode9b Yes 3
lode1c Yes 7
minor_lodes_v2a Yes 8
minor_lodes_v2b Yes 8
minor_lodes_v2c Yes 8
14.4.4Urucum North Underground model

 

14.4.4.1Descriptive statistics and top cuts

 

The statistics analysis was carried out using raw data, 1 m composites, and also 1 m composites with selected top cuts applied by domains. The results of this statistical study demonstrate high variability with characteristics common in gold deposits with CVs often high due to dilution caused by internal waste within the domains. Top cuts for the 1 m composites were selected following a review of outliers in the tail of the log histogram and log probability plots. Table 14.14 below shows the raw, 1 m composite and top cut 1 m composite statistics. Values in the Maximum column indicate the top cut values where the grades have been rounded.

amcconsultants.com

100

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.14 Urucum North Underground Resource statistics; raw, composited, and capped

SHT_type Assay Composited Capped
Count Mean SD Median Maximum Count Mean SD Median Maximum Count Mean SD Median Maximum
Lode 1                              
LODE0001 283 1.264 2.495 0.570 30.320 277 1.245 2.135 0.611 24.188 277 1.185 1.664 0.611 10.000
LODE1001 311 3.769 6.649 1.565 50.040 308 3.742 6.353 1.650 49.617 308 3.564 5.308 1.650 30.000
LODE1002 209 6.822 14.046 2.120 121.070 200 7.118 13.599 2.279 87.975 200 6.312 9.985 2.279 40.000
LODE1003 79 1.271 2.363 0.850 20.420 79 1.264 2.342 0.888 20.418 79 1.069 0.961 0.888 5.000
LODE1004 67 5.530 15.360 1.270 99.150 66 5.610 13.800 1.520 78.090 66 3.677 5.150 1.519 20.000
Lode 2                              
LODE0002 276 1.197 2.227 0.560 23.800 269 1.163 1.986 0.578 20.236 269 1.097 1.474 0.578 10.000
LODE2001 294 3.294 5.272 1.650 54.280 277 3.131 4.100 1.830 31.718 277 3.050 3.631 1.830 20.000
LODE2002 73 3.337 3.916 1.810 16.400 71 3.413 3.675 1.940 16.337 71 3.187 3.073 1.940 10.000
LODE2003 64 3.813 5.112 1.605 28.170 62 3.925 5.194 1.656 28.136 62 3.475 3.675 1.656 12.000
LODE2005 16 4.680 7.590 1.440 29.970 16 4.740 6.460 1.240 21.460 16 3.514 3.649 1.243 10.000
Lode 300                              
LODE0300 473 1.128 2.387 0.600 38.850 470 1.113 2.304 0.612 37.015 470 1.071 1.754 0.612 20.000
LODE3001 116 2.127 2.781 1.335 16.940 108 2.047 2.459 1.372 16.782 108 1.892 1.759 1.372 8.000
LODE3002 34 3.164 4.099 1.685 18.210 34 3.166 4.088 1.721 18.207 34 2.620 2.383 1.721 8.000
LODE3003 15 4.570 6.130 2.270 24.790 14 4.254 2.954 4.550 10.446 14 4.254 2.954 4.550 10.446
LODE3004 13 1.364 1.714 1.030 6.400 13 1.443 1.668 0.685 6.398 13 1.182 0.929 0.685 3.000
LODE3005 30 6.000 8.750 2.170 37.310 30 6.000 7.790 2.210 27.800 30 5.420 6.320 2.210 20.000
Lode 400                              
LODE0400 171 0.647 0.827 0.400 5.230 168 0.646 0.796 0.429 5.153 168 0.646 0.796 0.429 5.153
LODE4001 12 7.660 18.900 2.000 67.420 12 7.690 18.620 2.090 66.570 12 2.807 2.322 2.089 8.000
LODE4002 65 2.184 2.486 1.580 12.820 65 2.137 2.346 1.580 12.559 65 2.137 2.346 1.580 12.559
LODE4005 5 3.870 3.180 3.230 8.550 5 3.860 3.180 3.230 8.550 5 3.860 3.180 3.230 8.550
LODE0100 231 1.645 7.213 0.190 78.890 234 1.630 6.900 0.210 77.682 234 1.151 3.255 0.210 20.000
LODE0299 263 0.768 1.924 0.310 26.300 264 0.747 1.862 0.315 26.265 264 0.682 1.116 0.315 9.000
LODE0301 294 0.624 1.038 0.310 12.370 290 0.617 1.015 0.320 12.370 290 0.582 0.735 0.320 4.000
LODE0500 28 3.350 3.191 1.965 12.190 28 3.350 2.845 2.223 11.911 28 3.350 2.845 2.223 11.911
CO 79 0.689 0.698 0.550 5.700 80 0.689 0.683 0.556 5.699 80 0.689 0.683 0.556 5.699

SD = Standard Deviation; CV = Coefficient of Variation.

amcconsultants.com

101

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

14.4.5Urucum South Underground model
14.4.5.1Descriptive statistics

Raw statistics were reviewed for each domain and split by oxide and fresh where sufficient data existed to do so. Compositing was selected on 3 m intervals to be consistent with the Urucum MIK Open Pit resource estimate. A review of 2 m vs 3 m composites was undertaken grouped by variogram sector and showed no significant bias in the 3 m composites.

Composite statistics were generated for the 78 domains. Table 14.15 below shows 3 m composite statistics for domains with counts over 100. The results of this statistical study have shown high variability, some characteristics common in gold deposits with CVs often high due to the dilution caused by internal waste within the lodes. As a consequence of the high variability shown in the gold distribution, a large part of the gold metal is contained in the tail of the distribution and required analysis and treatment of the outliers.

Table 14.15 Urucum South Underground Resource statistics; Au (g/t)

LodeType Count Minimum Maximum Mean SE mean SD CV
LOCN702 3,920 0.003 51.50 1.76 0.04 2.62 1.49
LOCN700 3,831 0.003 24.19 1.16 0.02 1.39 1.20
LOUN510 2,978 0.011 36.90 1.10 0.02 1.29 1.18
LOCN704 1,686 0.005 56.07 1.48 0.07 3.06 2.07
LOCN703OX 1,518 0.002 34.90 1.03 0.04 1.69 1.64
LOCN703FR 1,361 0.005 69.63 1.60 0.08 2.97 1.85
LOLN001 1,198 0.005 48.10 1.78 0.11 3.71 2.08
LOLN300 703 0.005 19.76 1.14 0.07 1.76 1.55
LOUN540 606 0.038 5.55 0.90 0.02 0.60 0.66
LOLN002 553 0.005 19.20 1.71 0.10 2.33 1.36
LOUS902 533 0.005 14.35 2.05 0.11 2.42 1.18
LOUN602 515 0.021 14.70 1.16 0.06 1.43 1.24
LOLN299 385 0.005 44.49 0.78 0.13 2.63 3.40
LOUN520OX 363 0.013 6.14 0.66 0.03 0.60 0.90
LOLN301 341 0.005 19.00 0.78 0.07 1.32 1.69
LOUS900OX 307 0.004 10.63 0.85 0.07 1.22 1.43
LOLN400 295 0.005 34.01 1.00 0.13 2.28 2.27
LOUN601 260 0.001 22.49 1.20 0.11 1.71 1.42
LOUS903 260 0.005 20.92 1.11 0.13 2.01 1.82
LOUN530 210 0.01 3.39 0.62 0.03 0.45 0.72
LOUN606 184 0.07 5.72 1.21 0.07 0.90 0.74
LOUN603 179 0.02 9.60 1.13 0.08 1.05 0.93
LOUS901OX 175 0.005 3.96 0.70 0.05 0.62 0.89
LOCS800 166 0.005 17.03 0.88 0.12 1.53 1.73
LOCN709 153 0.011 16.07 1.20 0.14 1.68 1.40
LOCN705FR 147 0.04 5.68 0.92 0.09 1.04 1.13
LOUS900FR 125 0.005 4.31 0.50 0.06 0.66 1.31
LOUN626 114 0.01 2.13 0.56 0.03 0.37 0.66
LOUN520FR 112 0.036 3.34 0.76 0.06 0.63 0.83
LOCN707OX 107 0.02 9.97 0.84 0.14 1.42 1.70

Notes: Table shows 3 m composite statistical summary high grade outlier analysis. Only domains with > 100 counts shown.

SD = Standard Deviation; CV = Coefficient of Variation

amcconsultants.com

102

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Three metre composite samples have had a top cut applied to each lode based on the outliers shown in the logarithmic histograms and probabilities plots. Top cuts were within the 98th to 100th percentile. In case of lodes with less than 100 samples, no top cuts were applied to the outliers however the estimation search for these samples was reduced to 20 m. Table 14.16 shows the top cuts applied to the 3 m composites by lode.

 

 

 

amcconsultants.com

103

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.16 Urucum South Underground Resource statistics; raw gold data (g/t)

Lode No Lode type

No. 3 m

composite

Top cut-off

High grade value -

search ellipsoid

reduction

  Lode No Lode type

No. 3 m

composite

Top cut-off

High grade value -

search ellipsoid

reduction

  Lode No Lode type No. 3 m composite Top cut-off

High grade value -

search ellipsoid

reduction

800 LOCS800 166 4.8     722 LOCN722 18 9,999     617 LOUN617 13 1.25  
801 LOCS801 70 5.2     001 LOLN001 1,198 18     618 LOUN618 20 9,999  
802 LOCS802 59 9,999 2.7   002 LOLN002 553 12     620 LOUN620 6 9,999  
803 LOCS803 16 9,999 1.7   299 LOLN299 385 5     621 LOUN621 2 9,999  
804 LOCS804 7 9,999     300 LOLN300 703 9     623 LOUN623 11 9,999 2
902 LOUS902 533 9,999     301 LOLN301 341 6     624 LOUN624 3 9,999  
903 LOUS903 260 6     400 LOLN400 295 5     625 LOUN625 7 9,999  
904 LOUS904 31 9,999     500 LOLN500 10 9,999     626 LOUN626 114 2  
905 LOUS905 44 9,999     510 LOUN510 2,978 6     627 LOUN627 25 9,999 10
700 LOCN700 3,831 6.3     530 LOUN530 210 2.5     628 LOUN628 9 9,999  
701 LOCN701 4 9,999     540 LOUN540 606 3     900 LOUS900OX 307 5.5  
702 LOCN702 3,920 11     550 LOUN550 92 9,999 3   900 LOUS900FR 125 5.5  
704 LOCN704 1,686 13     600 LOUN600 38 9,999 5.3   901 LOUS901OX 175 2.56  
706 LOCN706 57 1.5     601 LOUN601 260 6.3     901 LOUS901FR 92 2.56  
708 LOCN708 35 9,999     602 LOUN602 515 7.3     703 LOCN703OX 1,518 11  
709 LOCN709 153 9     603 LOUN603 179 3.6     703 LOCN703FR 1,361 11  
710 LOCN710 29 9,999     605 LOUN605 61 9,999 3   705 LOCN705OX 57 7  
711 LOCN711 65 9,999 1.6   606 LOUN606 184 4.3     705 LOCN705FR 147 7  
712 LOCN712 14 9,999     607 LOUN607 7 9,999     707 LOCN707OX 107 9,999  
713 LOCN713 47 9,999 1.56   608 LOUN608 89 10     707 LOCN707FR 56 9,999  
715 LOCN715 40 9,999 2.51   609 LOUN609 30 9,999     721 LOCN721OX 75 9,999  
716 LOCN716 31 9,999 4.5   610 LOUN610 23 9,999 1.8   721 LOCN721FR 38 9,999  
717 LOCN717 45 9,999 2.62   612 LOUN612 2 9,999     520 LOUN520OX 363 3  
718 LOCN718 3 9,999     614 LOUN614 59 9,999 2.5   520 LOUN520FR 112 3  
719 LOCN719 8 9,999     615 LOUN615 53 9,999 5   613 LOUN613OX 38 20  
720 LOCN720 31 0.95     616 LOUN616 12 9,999     613 LOUN613FR 65 20  

 

 

amcconsultants.com

104

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.6Urucum East model
14.4.6.1Urucum East summary statistics

Drillholes within the database were assigned a unique 'zonecode' based on the numbering system. The unique database coding was used to control the compositing process. A downhole composite length of 1 m was used for all zones with a minimum composite length of 0.75 m set at the domain boundaries.

As expected, statistical analysis confirms that the HG Lode Zone is preferentially mineralized having a raw mean gold grade of 1.77 g/t and exhibiting moderate variability with a CV of around 1.29. The 99th percentile was 12.1 g/t Au and the maximum was 14.9 g/t Au. Based on the lack of any extreme outliers in the Lode or the colluvium, a top cut was not deemed necessary. Table 14.7 summarizes statistics for the high-grade zone and colluvium at Urucum East.

Table 14.17 Urucum East 1 m composites by domain - summary statistics

  High grade zone Colluvium
Raw Au ppm Raw Au ppm
Number 284 612
Minimum 0.005 0.005
Maximum 14.9 1.0
Mean 1.77 0.023
SD 2.27 0.07
CV 1.29 3.20

SD = Standard Deviation; CV = Coefficient of Variation

14.4.7Tap C (Other) model
14.4.7.1Raw sample data

Statistics were calculated for raw data separated by azimuth / dip groups, in each group the information was consolidated into sub-domains for variography. The main objective of analysing the statistics of the raw data was to understand the behaviour of gold grade for domains by analysing mean, standard deviation (Variance) to support the variography study.

The results of this shown high variability and some characteristics common in gold deposits with CVs often high due to the inclusion of internal waste dilution. As a consequence of the high variability shown in the gold distribution, a large part of the gold is situated at the tail of the distribution and in some cases will require that a top cut be applied.

Table 14.18 Raw data statistic summary - grouped ore domains gold (ppm)

Au (PPM) LODE111 LOGR020 LODE103
Count 3,406 1,271 161
Minimum 0.01 0 0.03
Maximum 24.6 30.2 7.92
Mean 1.119 0.721 0.735
SE of mean 0.031 0.042 0.066
Standard deviation 1.79 1.5 0.84
CV 1.602 2.081 1.143

SD = Standard Deviation; CV = Coefficient of Variation

amcconsultants.com

105

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.7.22 m composite data

As with the raw data, the 2 m composites from Tap C were analysed using the same approach. In addition to this, the composites were used to undertake top cut analysis.

The 2 m composites were separated by azimuth / dip groups for geostatistical analysis. These groups were further consolidated in sub-domains for variography. The VERT sector is shown in the following tables and figures.

Table 14.19 Tap C and gap, 2 m composite statistical summary of variogram sector VERT

Au (PPM) LODE3_4_5101 LODE102 LODE111 LOGR020 LODE103
Count 22,752 2,878 1,821 796 86
Minimum 0.00 0.00 0.01 0.01 0.07
Maximum 90.59 28.05 18.17 17.42 4.06
Mean 1.003 1.594 1.095 0.715 0.710
SD 2.44 2.46 1.61 1.22 0.62
CV 2.433 1.540 1.475 1.706 0.879

SD = Standard Deviation; CV = Coefficient of Variation

14.4.7.3     Treatment of high grade gold values (g/t)

 

The two metre composite samples have had a top grade for each lode based on the outlier shown in their respective logarithmic histograms and probability plots. The top cut grades are within the 98th to 100th percentile of the grade distribution. In some cases where there was a low quantity of samples present, the search ellipsoid was reduced to 20 m.

Table 14.20 details the high-grade Au treatment for each estimated ore lode.

Table 14.20 Tap C (other) model; top grade for 2 m composite - Au (g/t)

Lode code Dip group Variography group Top cut-off Red ellipsoid
Au (g/t) % Au (g/t)
LODE3_4_5101 3101 VERT VERT_101_102 10.0 98.94% 9,999.0
LODE102 102 VERT VERT_101_102 12.0 98.71% 9,999.0
LODE111 111 VERT VERT 8.0 98.68% 9,999.0
LOGR020 20 VERT VERT 6.0 98.99% 9,999.0
LODE103 103 80E VERT 9,999.0 100.00% 9,999.0
LODE201 201 VERT VERT 15.0 97.90% 9,999.0
LODE104 104 40E 40E 9,999.0 100.00% 9,999.0
LODE105 105 40E 40E 9,999.0 100.00% 9,999.0
LODE108 108 40E 40E 9,999.0 100.00% 9,999.0
LODE107 107 40E 40E_106_107 5.0 98.67% 9,999.0
LODE106 106 60E 40E_106_107 10.0 98.68% 9,999.0
LODE109 109 N20/60E N20/60E 9,999.0 100.00% 2.0
LODE110 110 N20/60E N20/60E 5.0 98.96% 9,999.0
LGEV3_4_5010 3,010 60W 60W 1.5 99.01% 9,999.0
LODE2101 2,101 OMNI LODE2101 10.0 98.84% 9,999.0
LGEV2010 2,010 OMNI LGEV2010 4.0 98.90% 9,999.0

 

amcconsultants.com

106

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.4.8Tap C (C3W and C3N) model

A statistical analysis based on 2 m composites for gold was undertaken within each mineralized domain. Table 14.21 shows summary statistics of gold for the main mineralized domains at Tap C3W and Tap C3N.

Top cuts have been applied to the 97.5% percentile of each estimation group to exclude outliers from the estimation (Table 14.21).

Table 14.21 Tap C3W and C3N 2 m composites by domain - summary statistics

Zone 1 2 7
Number 2162 461 154
Minimum 0.00 0.00 0.06
Maximum 27.73 4.06 5.03
Mean 1.06 0.81 0.87
SD 1.43 0.56 0.62
CV 1.35 0.69 0.71

SD = Standard Deviation; CV = Coefficient of Variation

Table 14.22 Tap C3W and C3N 2 m applied top cuts by domain

Zone Top-cut Au (g/t)
1 4.72
2 2.29
7 2.51
14.4.9Duckhead model
14.4.9.1Raw sample data

Statistics were calculated for raw data and reviewed in their respective azimuth / dip groups (groupings determined for variography). A statistical summary of the domains is shown in Table 14.23.

amcconsultants.com

107

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.23 Duckhead; raw data Au (g/t), statistical summary by domain

Domain Count Minimum Maximum Mean SD CV
LODE1 313 0 6844.6 165.3 441.9 2.68
LODE100 12 0.04 2.87 0.655 0.836 1.28
LODE101 54 0.08 4.09 0.869 0.828 0.95
LODE102 67 0.07 95.37 4.4 12.91 2.94
LODE103 9 0.4 2.06 0.857 0.535 0.62
LODE104 2 0.44 0.53 0.485 0.064 0.13
LODE105 6 0.42 0.7 0.535 0.095 0.18
LODE106 110 0.005 6.32 0.708 0.929 1.31
LODE107 232 0.005 95.34 2.225 8.159 3.67
LODE108 3 0.66 4.62 2.58 1.98 0.77
LODE109 35 0.15 13.47 1.335 2.685 2.01
LODE110FR 41 0.005 21.91 1.15 3.471 3.02
LODE110OX 37 0.02 13.64 1.193 2.278 1.91
LODE2 2,781 0.01 14018.6 11.4 267.3 23.40
LODE3 2,145 0.005 42.24 0.556 1.175 2.11
LODE31 857 0.005 36.94 0.639 1.806 2.83
LODE4FR 231 0.005 30.56 2.986 4.118 1.38
LODE4OX 1,991 0.005 93.09 5.17 8.056 1.56
LODE51FR 88 0.005 20.28 1.808 3.254 1.80
LODE51OX 92 0.02 14.34 1.264 1.938 1.53
LODE5FR 313 0.005 18.77 0.626 1.511 2.41
LODE5OX 1,493 0.005 17.62 0.789 1.359 1.72
LODE6FR 15 0.22 10.03 4.108 2.264 0.55
LODE6OX 22 0.3 31.86 6.33 8.45 1.33
LODE71 706 0.005 47.44 1.127 2.652 2.35
LODE7FR 123 0.005 9.68 0.832 1.257 1.51
LODE7OX 866 0.005 32.5 0.611 1.289 2.11
LODE8 594 0.005 53.63 0.811 2.441 3.01
LODE9 2789 0.005 24.81 0.73 1.163 1.60
LODE90 123 0.005 12.94 0.766 1.638 2.14

SD = Standard Deviation; CV = Coefficient of Variation

14.4.9.22 m composite data

Samples regularized on 2 m composite and then reviewed for appropriate top cuts for the grade outliers. Statistics for the 2 m composites by domain are shown in Table 14.24.

amcconsultants.com

108

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.24 Duckhead; 2 m composite statistical summary - grouped by ore lode

LODETYPE Count Minimum Maximum Mean SD CV
LODE1 199 0 3,557.5 166.2 300.4 1.81
LODE100 6 0.042 2.87 0.889 1.036 1.17
LODE101 30 0.244 2.385 0.869 0.561 0.65
LODE102 38 0.08 53.78 3.96 9.67 2.44
LODE103 6 0.314 1.6 0.794 0.478 0.60
LODE104 2 0.44 0.5297 0.4848 0.0634 0.13
LODE105 4 0.48 0.6999 0.555 0.0988 0.18
LODE106 56 0.01 3.951 0.701 0.755 1.08
LODE107 128 0.005 72.588 2.105 6.834 3.25
LODE108 2 2.437 2.994 2.716 0.394 0.15
LODE109 21 0.253 13.436 1.536 2.923 1.90
LODE110 46 0.007 11.434 1.147 2.074 1.81
LODE2 1,505 0.01 13,849.6 15.5 357.4 2.30
LODE3 1,129 0.005 21.1534 0.5527 0.829 1.50
LODE31 460 0.005 18.926 0.6329 1.3549 2.14
LODE4 1,213 0.008 68.86 4.894 6.789 1.39
LODE5 978 0.005 13.94 0.7875 1.2491 1.59
LODE51 94 0.025 14.31 1.612 2.294 1.42
LODE6 19 1.63 31.86 6.16 7.31 1.19
LODE7 519 0.005 16.4353 0.6389 0.9504 1.49
LODE71 376 0.005 35.078 1.099 2.22 2.02
LODE8 306 0.005 23.2124 0.8143 1.6019 1.97
LODE9 1,425 0.005 14.6913 0.7269 0.9674 1.33
LODE90 73 0.044 7.05 0.721 1.215 1.68

SD = Standard Deviation; CV = Coefficient of Variation

14.4.9.3Top cuts

The 2 m composite samples have had a top cut applied to each domain based on an analysis of outliers in logarithmic histogram and probability plots. The top cut grades are within 98th to 100th percentile of the grade distribution. In case of domains with less than 100 composites, no grade capping was applied however the range of the estimation was restricted to 20 m.

amcconsultants.com

109

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.25 Duckhead determined top cuts for each lode

Domain codes Au capping (g/t) Lode codes Au capping (g/t)
LODE1 1 900 LODE2 2 45
LODE100 100 No LODE3 3 3
LODE101 101 No LODE31 31 4
LODE102 102 4.5 LODE4 4 33
LODE103 103 No LODE5 5 6.5
LODE104 104 No LODE51 51 8
LODE105 105 No LODE6 6 No
LODE106 106 No LODE7 7 4
LODE107 107 13.5 LODE71 71 6.5
LODE108 108 No LODE8 8 6
LODE109 109 No LODE9 9 8
LODE110 110 No LODE90 90 No
14.5Variography
14.5.1Introduction

Variography is used to describe the spatial variability or correlation of an attribute (gold, silver, etc.). The spatial variability is traditionally measured by means of a variogram, which is generated by determining the averaged squared difference of data points at a nominated distance (h), or lag (Srivastava and Isaacs, 1989). The averaged squared difference (variogram or γ (h)) for each lag distance is plotted on a bivariate plot, where the X-axis is the lag distance and the Y-axis represents the average squared differences (γ(h)) for the nominated lag distance.

Several types of variogram calculations are employed to determine the directions of the continuity of the mineralization:

Traditional variograms are calculated from the raw assay values.
Log-transformed variography involves a logarithmic transformation of the assay data.
Gaussian variograms are based on the results after declustering and a transformation to a Normal distribution.
Pair wise-relative variograms attempt to ‘normalize’ the variogram by dividing the variogram value for each pair by their squared mean value.
Correlograms are ‘standardized’ by the variance calculated from the sample values that contribute to each lag.

Fan variography involves the graphical representation of spatial trends by calculating a range of variograms in a selected plane and contouring the variogram values. The result is a contour map of the grade continuity within the domain.

14.5.2Tap AB Open Pit model variography

Grade and indicator variography was generated to enable grade estimation via MIK and change of support analysis to be completed. In addition, Gaussian variograms were also examined as part of the change of support process. Indicator thresholds for Domains to be estimated via MIK had variograms modelled with every third variogram typically modelled. Variograms not modelled have had their parameters interpolated based on the bounding modelled variograms. Interpreted anisotropy directions correspond well with the modelled geology and overall geometry of the interpreted domains. Grade variography was modelled for OK grade estimation.

amcconsultants.com

110

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.5.3Urucum Open Pit model variography

The Urucum open pit model variography was done using the same procedures outline above for the Tap open pit model.

14.5.4Tap AB Underground model variography

The analysis of spatial variability of the TAP-AB Deposit was performed by analysis of experimental and fitting pair wise semi-variograms using 3 m composites combined into 8 variography groups.

14.5.5Urucum North Underground model variography

The analysis of spatial variability of the Urucum Underground Project was carried out by analysis of experimental and modelled semi-variograms. 1 m lode composites were top cut and grouped into a single domain for variogram analysis. Despite the high variability of the Au grades, the raw semi-variograms were made using the traditional variogram function. A variogram was modelled down-hole to obtain the nugget effect.

14.5.6Urucum South Underground model variography

The analysis of spatial variability for the Urucum South Underground model was carried out by analysis of experimental and fitted semi-variograms. 3 m composites were used with a top cut applied and the data grouped within variography groups as defined by differences in lode morphology, azimuth, and dip.

14.5.7Urucum East model variography

Variography has been used to analyse the spatial continuity within the mineralized zones and to determine appropriate estimation inputs to the interpolation process. The variogram modelling process generally followed these steps:

Calculate and model the omni-directional or down hole variogram to characterize the Nugget effect.
Systematically calculate orientated variograms in 3 dimensions to identify the plane of greatest continuity.
Calculate a fan of variograms within the plane of greatest continuity to identify the direction of maximum continuity within the plane. Model the variogram in the direction of maximum continuity and the orthogonal directions.

Experimental normal variography with lags of 25 m was performed on 1 m downhole composites. Directional variography for gold within the HG zone revealed generally well-structured behaviour with maximum ranges of 76 m (major range) and 52 m (semi-major range) within the plane of mineralization. The mineralized plane has a gentle plunge towards the North (-30° to > 0°). An omni-directional variogram model with maximum ranges of 125 m in the horizontal plane was modelled for the colluvium domain.

14.5.8Tap C (other) model variography

The analysis of spatial variability for the Tap C model was carried out by analysis of experimental and fitted semi-variogram models. 2 m composites with an applied top cut grade were used and the data within the domains grouped into their variography groups as defined by statistical analysis. This procedure of grouping was applied to also improve the variography of discontinuous lodes with a small number of samples.

The criteria used to select the groups were based on statistical analysis and cumulative probability plots that showed no significant differences between the grades inside the domains. Domain groups however had key differences in morphology, azimuth, and dip, and this was reviewed with site geologists.

amcconsultants.com

111

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Due to the high variability of the Au grades, the raw variograms were generally impossible to interpret.

The variogram methodology is pair wise relative semi-variogram. Journell 2008 - GSLIB Second Edition “With this variogram, each pair is normalized by the squared average of the tail and head values.

 

Practical experience has shown that the general relative and pair wise relative sample semi-variograms are resistant to data sparsity and outliers when applied to positively skewed sample distribution”. It should be made clear that the transformation of the original grades into Gaussian distributed values (Gaussian anamorphosis) before calculating the variograms was a solution considered, however, it would have generated effectively the same results.

In general, the variograms show a relatively low nugget effect but the ranges of the first geostatistical structure are short and often over 80% of the total variability is reached within 20 m to 40 m.

Fitting the semi-variogram was achieved by first fitting the omnidirectional semi-variogram with a short lag to get nugget effect and then fitting the directional semi-variogram.

14.5.9Tap C (C3N and C3W) model variography

Variography has been used to analyse the spatial continuity within the mineralized zones and to determine appropriate estimation inputs to the interpolation process. The variogram modelling process generally followed these steps:

Review the omni-directional or down-hole variogram to characterize the Nugget Effect. Due to the poor resultant downhole variogram, the nugget was modelled from the orientated variograms.
Systematically calculate orientated variograms in 3 dimensions to identify the plane of greatest continuity.
Calculate a fan of variograms within the plane of greatest continuity to identify the direction of maximum continuity within the plane. Model the variogram in the direction of maximum continuity and the orthogonal directions.

Experimental pair wise variography with lags of 10 m was performed on 2 m downhole composites.

Directional variography for gold within the 3 zones defining the C3W and C3N areas show a high nugget and maximum ranges up to 161 m with the first structure range between 16 m and 46 m within the plane of the dipping domains. A lag spacing of 10 m was selected to approximate the drillhole spacing within these shallow domains.

14.5.10Duckhead model variography

 

The 2 m composites grouped into 4 variogram sectors based on domain orientation. Lode 1 (the core of Duckhead Main mineralization) has been separated out with its own variogram sector.

amcconsultants.com

112

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.6Block modelling
14.6.1Tap AB and Urucum Open Pit block models

For the Tap AB and Urucum Open Pit Resources 3D block models were created in the National grid (UTM SAD69 Zone 22N) using Vulcan mining software. The parent block size was selected on the basis of the average drill spacing together with consideration of mining parameters currently in use at the Tucano Gold Project. A parent cell size of 9 mE by 20 mN by 8 mRL which was sub-blocked down to 3 mE by 5 mN by 4 mRL (to ensure adequate volume representation). The models covered all the interpreted mineralization zones and included suitable additional waste material to allow later pit optimization studies. Block coding was completed on the basis of the block centroid, wherein a centroid falling within any wireframe was coded with the wireframe solid attribute. The block models are non-rotated.

The main block model parameters are summarized below in Table 14.26 and Table 14.27. Variables were coded into the block models to enable MIK and OK estimation and subsequent MIK change of support and grade tonnage reporting. A visual review of the wireframe solids and the block model indicated correct flagging of the block model. Additionally, a check was made of coded volume versus wireframe volume which confirmed the above.

Table 14.26 Tap AB Gold Deposit - Open Pit Resource block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 401,640 92,740 -627
Max coordinates 402,855 95,640 325
Block size (m) 9.0 20.0 8.0
Sub block size (m) 3.0 5.0 4.0
Rotation (° around axis)

Table 14.27 Urucum Gold Deposit - Open Pit Resource block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 401,500 97,940 -683
Max coordinates 402,319 100,440 317
Block size (m) 9.0 20.0 8.0
Sub block size (m) 3.0 5.0 4.0
Rotation (° around axis)
14.6.2Tap AB and Urucum Underground block models

For the Tap AB and Urucum Underground Resources 3D block models were created in the National grid (UTM SAD69 Zone 22N) using Surpac mining software. Estimation was completed in Isatis using parent cells and then script imported into an attributed and sub blocked Surpac model on a domain by domain basis such that the domains were completely filled to sub cell resolution with the estimated blocks. The block models for the Urucum North Underground and Urucum South Underground both extend into one another however the resource reporting for these uses the 99,400 mN northing as the official divisor between the 2 models.

amcconsultants.com

113

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.28 Tap AB Underground block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. Coordinates 401,640 92,740 -627
Max Coordinates 402,855 95,640 325
Block size (m) 9.0 20.0 8.0
Sub Block size (m) 1.125 5 2.0
Rotation (° around axis)

Table 14.29 Urucum North Underground block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 401,500 97,940 -683
Max coordinates 402,316 100,440 317
Block size (m) 8.0 20.0 20.0
Sub block size (m) 1.0 5.0 2.5
Rotation (° around axis)

Table 14.30 Urucum South Underground block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 401,500 97,940 -683
Max coordinates 402,319 100,440 317
Block size (m) 9.0 20.0 8.0
Sub block size (m) 1.125 5.0 2.0
Rotation (° around axis)
14.6.3Urucum East, Tap C, and Duckhead block models

The Urucum East, Tap C and Duckhead block models were created in the National grid (UTM SAD69 Zone 22N) using Surpac software. For Duckhead and the Tap C Other Areas, Isatis estimated centroids were imported using the same methodology as the Tap AB Underground and Urucum Underground models. Urucum East and the Tap C (C3N and C3W areas) were estimated directly inside Surpac.

Table 14.31 Urucum East Gold Deposit block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 402,600 100,000 0
Max coordinates 403,250 100,490 320
Block size (m) 5.0 10.0 2.0
Sub block size (m) 0.625 2.5 0.5
Rotation (° around axis)

 

amcconsultants.com

114

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Table 14.32 Tap C Gold Deposit block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 401,600 95,640 -355
Max coordinates 402,704 97,940 285
Block size (m) 8.0 20.0 4.0
Sub block size (m) 2.0 5.0 2.0
Rotation (° around axis)

Table 14.33 Duckhead Gold Deposit block model parameters

  Easting (X) Northing (Y) RL (Z)
Min. coordinates 407,750 87,750 -250
Max coordinates 409,750 90,250 300
Block size (m) 5.0 10.0 2.0
Sub block size (m) 0.625 2.5 1.0
Rotation (° around axis) -45°
14.7Grade estimation
14.7.1Tap AB and Urucum Open Pit block models
14.7.1.1 Introduction

MIK was applied to grade estimation at the Tap AB and Urucum Gold Deposits within the defined indicator mineralization shells. A number of minor domains were estimated via OK. Estimation was completed in the mining package Vulcan using the GSLib geostatistical software while geostatistical change of support parameters was developed in Isatis geostatistical software. MIK is considered a robust estimation methodology for grade estimates for gold deposits such as Tap AB and Urucum where high levels of short scale variability are present. MIK grade estimation with change of support has been applied to produce ‘recoverable’ gold estimates targeting a selective mining unit (SMU) of 3 mE x 5 mN x 4 mRL.

14.7.1.2The MIK method

The MIK technique is implemented by completing a series of OK estimates of binary transformed data. A composite sample, which is equal to or above a nominated cut-off or threshold, is assigned a value of 1, with those below the nominated indicator threshold being assigned a value of 0. The indicator estimates, with a range between 0 and 1, represent the probability the point will exceed the indicator COG. The probability of the points exceeding a cut-off can also be considered broadly equivalent to the proportion of a nominated block that will exceed the nominated COG.

The estimation of a complete series of indicator cut-offs allows the reconstitution of the local histogram or conditional cumulative distribution function (ccdf) for the estimated point. Based on the ccdf, local or block properties, such as the block mean and proportion (tonnes) above or below a nominated cut-off grade can be investigated.

14.7.1.3Post MIK processing - E-type estimates

The E-type estimate provides an estimate for the grade of the total block or bulk-mining scenario. This is achieved by discretizing the calculated ccdf for each block into a nominated number of intervals and interpolating between the given points with a selected function (e.g. the linear, power or hyperbolic model) or, by applying intra-class mean grades. The sum of all these weighted interpolated points or mean grades enables an average whole block grade to be determined.

amcconsultants.com

115

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The following example shows the determination of an E-type estimate for a block containing three indicator cut-offs.

The indicator cut-offs and associated probabilities calculated are shown in Table 14.34.

Table 14.34 Tap AB and Urucum open pit block model Indicator cut-off and probability

Indicator COG Au (g/t) Indicator probability (cumulative)
Minimum grade * 0  0.00 **
Indicator 1 1 0.40
Indicator 2 2 0.65
Indicator 3 3 0.85
Maximum grade * 4 1.00 **

Notes:

* COGs determined by the user.

** Indicator probability is assumed at the minimum and maximum cut-off.

The whole block grade can now be determined in this block with the following parameters used for the purposes of the interpolation:

Number of discretization intervals: 4.
Linear extrapolation between all points (median grade between nominated cut-offs).

The worked example is then calculated with the following steps:

Interval 1 (0-1 g/t Au)      median grade x probability / proportion attributed to the interval (0.5 g/t Au x 0.40 = 0.200).
Interval 2 (1 - 2 g/t Au)     median grade x proportion (1.5 g/t Au x 0.25 = 0.375).
Interval 3 (2 - 3 g/t Au)     median grade x proportion (2.5 g/t Au x 0.20 = 0.500).
Interval 4 (3 - 4 g/t Au)     median grade x proportion (3.5 g/t Au x 0.15 = 0.525).
Calculate total grade         average all calculated intervals ((0.2 + 0.375 + 0.500 + 0.525) / 1) = 1.60 g/t Au.

It is also possible from this example to calculate the proportion and grade above a nominated cut-off (e.g. 2 g/t - at sample support or complete selectivity). The following steps would be undertaken to calculate the tonnes and grade at sample selectivity using a 2 g/t Au COG:

Interval 3 (2 - 3 g/t Au)      median grade x proportion (2.5 g/t Au x 0.20 = 0.500).
Interval 4 (3 - 4 g/t Au)      median grade x proportion (3.5 g/t Au x 0.15 = 0.525).
Calculate total grade average all calculated intervals ((0.500 + 0.525) / 0.35) = 2.93 g/t Au with 0.35% of the block above the COG.

 

The effect of using a non-linear model to interpolate between COGs is to shift the grade weighting associated with that cut-off away from the median. For Tap AB and Urucum, the intra-class means based on the cut composite data have been used to reconstitute the ccdf and produce block statistics.

It is noted, however, that the calculation of the E-type estimate and complete selectivity often does not allow mine planning to the level of selectivity which is proposed for production. To achieve an estimate which reflects the levels of mining selectivity envisaged, a selective mining unit (SMU) correction is often applied to the calculated ccdf.

amcconsultants.com

116

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.7.1.4Support correction (selective mining unit estimation)

A range of techniques are known to produce a support correction and therefore allow for selective mining unit emulation. The common features of the support correction are:

Maintenance of the mean grade of the histogram (E-type mean).
Adjustment of the histogram variance by a variance adjustment factor (the ‘f’ factor).

The variance adjustment factor, used to reduce the histogram or ccdf variance, can be calculated using the variogram model. The variance adjustment factor is often modified to account for the likely grade control approach or ‘information effect’.

In simplest terms, the variance adjustment factor takes into account the known relationship derived from the dispersion variance.

Total variance = variance of samples within blocks + variance between blocks.

The variance adjustment factor is calculated as the ratio of the variance between the blocks and the variance of the samples within the blocks, with a small ratio (e.g. 0.10) indicating a large adjustment of the ccdf variance and large ratio (e.g. 0.80) representing a small shift in the ccdf.

Two simple support corrections that are available include the Affine and Indirect Lognormal correction, which are both based on the permanence of distribution. The discrete Gaussian model is often applied to global change of support studies and has been generated on the composite dataset as a comparison. The indirect lognormal correction was applied to the MIK grade estimates.

14.7.1.5Indirect lognormal correction

The indirect lognormal correction can be implemented by adjusting the quantiles (indicator cut-offs) of the ccdf with the variance adjustment factor so that the adjusted ccdf represents the statistical characteristics of the block volume of interest.

This is implemented with the following formula:

 

amcconsultants.com

117

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

  

At the completion of the quantile adjustments, grades and tonnages (probabilities are then considered a pseudo tonnage proportion of the blocks) at a nominated COG can be calculated using the methodology described above (E-type). The indirect lognormal correction, as applied to the Tucano Gold Project, is the best suited of the common adjustments applied to MIK to produce selective mining estimates for positively skewed distributions.

14.7.1.6MIK and OK parameters

 

MIK estimates were completed using the indicator variogram models and a set of ancillary parameters controlling the source and selection of composite data. The sample search parameters were defined based on the variography and the data spacing, and a series of sample search tests performed in Isatis geostatistical software. A total of 17 indicator thresholds were estimated for all estimation domains.

OK estimates were completed on the minor estimation domains and the colluvium using the grade variogram models (Section 14.6), and a set of ancillary parameters controlling the source and selection of composite data. The sample search parameters were defined based on the variography and the data spacing, and a series of sample search tests performed in Isatis geostatistical software.

The sample search parameters for the MIK estimations are provided in Table 14.35 and Table 14.36.

A combination of soft and hard domain boundaries was used for the MIK portion of the estimate to reflect continuity between domains or otherwise. A three-pass estimation strategy was applied to each domain, applying a progressively expanded and less restrictive sample search to the successive estimation pass, and only considering blocks not previously assigned an estimate. Parent cell estimations (9 mE by 20 mN by 8 mRL) were applied throughout and discretization was applied on the basis of 3 X by 3 Y by 3 RL for 27 discretization points per block.

amcconsultants.com

118

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.35 Tap AB Gold Deposit - Open Pit Resource MIK sample search criteria

Domain Pass

Sample search orientation

(dip / dip direction˚)

Sample search distance

(m)

Numbers of samples Boundary condition
Major

Semi-

major

Minor Major Semi-major Minor Min. Max.

Max per

drillhole

101 Pass 1 0/10 -20/280 -70/100 50 50 15 32 32 5 Hard
Pass 2 0/10 -20/280 -70/100 100 100 30 24 32 - Soft
Pass 3 0/10 -20/280 -70/100 300 300 50 12 32 - Soft
200 Pass 1 -90/0 0/0 0/270 50 50 15 24 24 5 Hard
Pass 2 -90/0 0/0 0/270 100 100 30 24 24 - Soft
Pass 3 -90/0 0/0 0/270 300 300 50 12 24 - Soft
1,000 Pass 1 -80/290 0/20 -10/110` 50 50 15 32 32 5 Hard
Pass 2 -80/290 0/20 -10/110` 100 100 30 24 32 - Hard
Pass 3 -80/290 0/20 -10/110` 500 500 50 12 32 - Hard
2,000 Pass 1 0/20 -80/290 -10/121 50 50 15 32 32 5 Soft
Pass 2 0/20 -80/290 -10/121 100 100 30 24 32 - Soft
Pass 3 0/20 -80/290 -10/121 500 500 50 12 32   Soft
3,000 Pass 1 -40/0 -50/180 0/90 50 50 15 32 32 5 Hard
Pass 2 -40/0 -50/180 0/90 100 100 30 24 32 - Soft
Pass 3 -40/0 -50/180 0/90 300 300 50 12 32   Soft

 

Table 14.36 Urucum Gold Deposit - Open Pit Resource MIK sample search criteria

Domain Pass

Sample search orientation

(dip / dip direction˚)

Sample search distance

(m)

Numbers of samples

Boundary

condition

Major

Semi-

major

Minor Major

Semi-

major

Minor Min. Max.

Max per

drillhole

100 Pass 1 0/350 -70/80 -20/260 50 50 15 24 32 5 Hard
Pass 2 0/350 -70/80 -20/260 100 100 30 24 32 5 Soft
Pass 3 0/350 -70/80 -20/260 300 300 50 12 32 - Soft

200

north1

Pass 1 0/0 -70/90 -20/270 50 50 15 24 32 5 Hard
Pass 2 0/0 -70/90 -20/270 100 100 30 24 32 5 Soft
Pass 3 0/0 -70/90 -20/270 300 300 50 12 32 - Soft

200

south2

Pass 1 0/350 -70/80 -20/260 50 50 15 24 32 5 Hard
Pass 2 0/350 -70/80 -20/260 100 100 30 24 32 5 Soft
Pass 3 0/350 -70/80 -20/260 300 300 50 12 32 - Soft

300,

4003

Pass 1 0/0 -75/90 -15/270 50 50 15 24 32 5 Hard
Pass 2 0/0 -75/90 -15/270 100 100 30 24 32 - Hard
Pass 3 0/0 -75/90 -15/270 300 300 50 12 32 - Soft

Notes:

(1) for block centroids north of 98,915 mN.

(2) for block centroids south of 98,915 mN.

(3) Domains 300 and 400 estimated simultaneously.

The sample search parameters for the OK estimations are provided in Table 14.37 and Table 14.38.

Hard boundaries were applied throughout in the case of the domains estimated by OK. Only one estimation pass was generally considered with a search neighbourhood of sufficient parameters to enable estimation of all required blocks. If required a second neighbourhood with expanded dimensions and relaxed sample requirements was applied to complete the estimation. Estimations were on the basis of SMU block dimensions throughout (3 mE by 5 mN by 4 mRL) and discretization was applied on the basis of 2 X by 2 Y by 2 RL for 8 discretization points per block.

amcconsultants.com

119

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.37 Tap AB Gold Deposit - Open Pit Resource OK sample search criteria

Domain Pass

Sample search orientation

(dip / dip direction˚)

Sample search distance

(m)

Numbers of samples
Major

Semi-

major

Minor Major

Semi-

major

Minor Min. Max.

Max per

drillhole

Boundary

condition

102 Pass 1 0/0 -20/270 -70/90 200 200 20 6 6 3 H
110 Pass 1 -13/38 16/312 69/90 200 200 20 6 12 3 H

Table 14.38 Urucum Gold Deposit - Open Pit Resource OK sample search criteria

Domain Pass

Sample search orientation

(dip / dip direction˚)

Sample search distance

(m)

Numbers of samples
Major

Semi-

major

Minor Major

Semi-

major

Minor Min. Max.

Max per

drillhole

Boundary

condition

510 to

550

Pass 1 0/0 -15/270 -75/90 50 50 15 6 8 3 H
Pass 2 0/0 -15/270 -75/90 200 200 30 4 8 - H
700 Pass 1 0/0 -15/270 -75/90 50 50 15 6 8 3 H
Pass 2 0/0 -15/270 -75/90 100 100 30 4 8 - H

All relevant statistical information was recorded to enable validation and review of the MIK estimates. The recorded information included:

Number of samples used per block estimate.
Number of drillholes from which samples selected.
Average distance to samples per block estimate and distance to nearest sample.
Estimation flag to determine in which estimation pass a block was estimated.
Number of drillholes from which composite data were used to complete the block estimate.

The estimates were reviewed visually and statistically prior to being accepted. The review included the following activities:

Comparison of the E-type estimate versus the mean of the composite dataset, including weighting where appropriate to account for data clustering.
Comparison of the reconstituted cumulative conditional distribution functions of the estimated blocks (indicator kriging) versus the input composite data.
Visual checks of cross sections, long sections, and plans.

Alternative estimates were also completed to test the sensitivity of the reported model to the selected MIK interpolation parameters. An insignificant amount of variation in overall grade was noted in the alternate estimations.

14.7.1.7Change of support

Applying the modelled variography, variance adjustment factors were calculated to emulate a 3 mE x 5 mN x 4 mRL selective mining unit (“SMU”) via the indirect lognormal change of support. The intra-class composite mean grades were used in calculating the whole block and SMU grades. The change of support study also included the calculation of the theoretical global change of support via the discrete Gaussian change of support model. An ‘information effect’ factor is commonly applied to the originally derived panel-to-block variance ratios to determine the final variance adjustment ratio. The goal of incorporating information effect is to calculate results taking into account that mining takes place based on grade control information. There will still be a quantifiable error associated with this data and it is this error we want to incorporate. This is achieved in practice by running a test kriging estimation of an SMU using grade control data (the results required to incorporate this option in the change of support do not depend on the assay data, so the grade control data can be hypothetical). The incorporation of the information effect is commonly found to be negligible, however it can have a significant effect in some cases. In this case, the information effect factor was found to have a minor effect and has been incorporated in the calculation. The variance adjustment ratios are provided in Table 14.39.

amcconsultants.com

120

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.39 Variance adjustment ratios (3 mE x 5 mN x 4 mRL SMU)

Tap AB
Zone 101 200 1000 2000 3000
Variance adjustment factor (f) 0.20 0.25 0.09 0.30 0.15
Urucum
Zone 100 200 300 400 -
Variance adjustment factor (f) 0.15 0.30 0.15 0.25 -
14.7.2Tap AB Underground - OK estimation

Gold grades were estimated by three consecutive OK runs performed using 3 m composites, parent cells of 9 m x 20 m x 8 m (x, y, z), hard wireframe boundaries and variograms determined by variogram sector. The key parameters of the estimation are chosen after several tests, a critical parameter being the number of composites to be used for the estimates. Table 14.40 details the first and second neighbourhood searches for each of the lode / oxide domains.

The search radii are related to the semi-variogram ranges for first and second runs and for the third run a large neighbourhood was used to fill the lode wireframe for blocks not estimated.

1st neighbourhood: search radius value varying to fit 85 - 90% of the variogram sill. Minimum number of samples = 4, Maximum = 32. 8 sectors and minimum of 3 drillholes in a grid of 120° spaced, 3D continuity.
2nd neighbourhood: search radius 2x of neighbourhood 1. Minimum number of Samples = 4, Maximum = 32, 8 sectors and minimum of 2 drillholes, 2D continuity.
3rd neighbourhood represents the search ellipsoid to estimate remain blocks inside the lode wireframe = 1,500 x 1,500 x 100 m. Minimum of 1 Sample and a maximum of 4.

amcconsultants.com

121

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.40 Tap AB Gold Deposit - Underground Resource; orientation and radius of search radius of individual lodes / oxide domains

Ore shoots VarSector No blocks Az Dip Plunge Range neigh 1 Range neigh 2
Sample index

Block

index

Dist X Dist Y Dist Z Dist_U Dist_V Dist_W
LODE10OX 3,010 LODE10 2,905 10 -50 0 65 65 25 130 130 50
LODE11A 111 LODE6_11 4,027 0 85 0 35 55 10 70 110 20
LODE11B 112 LODE6_11 1,713 0 90 0 35 55 10 70 110 20
LODE12AOX 3,121 LODE12 393 0 -85 0 55 55 20 110 110 40
LODE12B 122 LODE12 102 10 -75 0 55 55 20 110 110 40
LODE12C 123 LODE12 218 0 -85 0 55 55 20 110 110 40
LODE12DOX 3,124 LODE12 153 0 85 0 55 55 20 110 110 40
LODE14A 141 LODE14 1,654 0 90 0 35 55 10 70 110 20
LODE14BOX 3,142 LODE14 1,655 15 -85 0 35 55 10 70 110 20
LODE1A 11 LODE1_3_5 99 -10 -85 0 35 55 10 70 110 20
LODE1BOX 3,012 LODE1_3_5 60 10 90 0 35 55 10 70 110 20
LODE1COX 3,013 DIP45W 98 10 -60 0 35 55 10 70 110 20
LODE3OX 3,003 LODE1_3_5 296 5 90 0 35 55 10 70 110 20
LODE4OX 3,004 LODE4 2,513 0 90 0 25 45 30 50 90 60
LODE5OX 3,005 LODE1_3_5 418 0 90 0 35 55 10 70 110 20
LODE6OX 3,006 LODE6_11 820 -10 90 0 35 55 10 70 110 20
LODE9AOX 3,091 DIP45W 1,514 0 -45 0 35 55 10 70 110 20
LODE9BOX 3,092 DIP45W 121 15 -45 0 35 55 10 70 110 20
MLODE2AOX 3,211 MLODES 2,359 0 -80 0 35 55 10 70 110 20
MLODE2BOX 3,212 MLODES 466 5 90 0 35 55 10 70 110 20
MLODE2COX 3,213 MLODES 141 0 90 0 35 55 10 70 110 20
LODE10FR 5,010 LODE10 1,762 10 -50 0 65 65 25 130 130 50
LODE12AFR 5,121 LODE12 434 0 -85 0 55 55 20 110 110 40
LODE12DFR 5,124 LODE12 505 0 85 0 55 55 20 110 110 40
LODE14BFR 5,142 LODE14 2,236 15 -85 0 35 55 10 70 110 20
LODE1BFR 5,012 LODE1_3_5 54 10 90 0 35 55 10 70 110 20
LODE1CFR 5,013 DIP45W 62 10 -60 0 35 55 10 70 110 20
LODE3FR 5,003 LODE1_3_5 118 5 90 0 35 55 10 70 110 20
LODE4FR 5,004 LODE4 1,324 0 90 0 25 45 30 50 90 60
LODE5FR 5,005 LODE1_3_5 249 0 90 0 35 55 10 70 110 20

 

amcconsultants.com

122

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Ore shoots VarSector No blocks Az Dip Plunge Range neigh 1 Range neigh 2
Sample index Block index Dist X Dist Y Dist Z Dist_U Dist_V Dist_W
LODE6FR 5,006 LODE6_11 585 -10 90 0 35 55 10 70 110 20
LODE9AFR 5,091 DIP45W 960 0 -45 0 35 55 10 70 110 20
LODE9BFR 5,092 DIP45W 312 15 -45 0 35 55 10 70 110 20
MLODE2AFR 5,211 MLODES 3,380 0 -80 0 35 55 10 70 110 20
MLODE2BFR 5,212 MLODES 203 5 90 0 35 55 10 70 110 20
MLODE2CFR 5,213 MLODES 163 0 90 0 35 55 10 70 110 20

VarSector = Variogram Sector, Dist = Distance

 

 

amcconsultants.com

123

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

14.7.2.1Estimate validation

The statistical validation of the OK estimated grades involved a comparison of these grades by lode in each neighbourhood with the top cut 3 m composite mean grade (3M CMP), NN estimated grade and the slope of regression. This comparison was carried out to have a better understanding of the performance of kriging and allow parameter adjustments for each neighbourhood.

Swath Plot analysis was applied to validate the grades along the block model in 3 main directions: X, Y, and Z. All cases observe a reasonable correlation of samples and block models, especially for the Measured and Indicated categories. Some differences were observed, however, related to Inferred blocks and small number of blocks and samples.

14.7.3Urucum North Underground OK estimation

Au block grades (g/t) were estimated by three consecutive OK runs performed using 1 m composites, parent cells of 8 m x 20 m x 20 m (x, y, z), hard wireframe boundaries and a variogram determined from all lodes. The OK run was carried out in three successive runs with its parameters based on QKNA analysis.

The search ellipse is divided in eight octants and an optimum number of four data points per octant was sought (i.e. 32 data points in total). In the first run, a minimum of four data points (in total) was required for the block to be estimated. This condition is relaxed to one in subsequent runs as shown below.

Estimation Pass 1:

1Minimum number of samples: 12.
2Search Ellipsoid - 130 x 120 x 25 m - Semi-variogram range considering all structures.
3Optimum number of samples for each octant: 3.
4Maximum number of consecutive empty octants: 3.

Estimation Pass 2:

5Minimum number of Samples: 12.
6Search Ellipsoid - 130 x 120 x 25 m - Semi-variogram range considering all structures.
7Optimum number of samples for each octant: 3.
8Maximum number of consecutive empty octants: 7.

Estimation Pass 3:

9Minimum number of Samples: 4.
10Search Ellipsoid - Large enough to estimate all blocks.
11Optimum number samples per octant: No restriction.
12Maximum number of consecutive empty octants: No Restriction.

The search ellipses were generally orientated in the same directions as the variogram anisotropy axes.

Search ellipsoids were reduced to 20 m for composites greater than a defined cut-off. The aim of the reduced search was to avoid smoothing of very high grades in the estimate. The quality of the OK is variable based on the criteria of the slope of regression, however many blocks were poorly estimated due to the paucity of data and relatively poor grade continuity in some areas, consequently the grades could be smoothed, and it is suggested to implement a closer spaced drilling to reduce this effect.

amcconsultants.com

124

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.7.3.1Urucum North Underground model - estimate validation

The statistical validation of gold estimated grades involved a comparison of grades estimated in each neighbourhood with the sample mean grade, NN estimated grades, and the slope of regression separated by lodes. This comparison was undertaken to gain a better understanding of the performance of kriging, allow adjustments of parameters for each neighbourhood, and to get information on the number of estimated blocks.

A Swath Plot analysis was also applied to validate the grades along the block model in 3 main directions: X, Y, and Z. A comparison was made against sample mean grade, OK estimated grades, and NN estimated grades. All cases observe a reasonable correlation of samples and block models, especially at Measured and Indicated regions. It also showed some differences but related to Inferred blocks and a small number of blocks and samples.

14.7.4Urucum South Underground model - OK estimation

Gold grades are estimated by OK using 3 m composites within parent cells of dimension 9 m x 20 m x 8 m (x, y, z) using hard wireframe boundaries and applying variography based on domains grouped by variogram sector. The key parameters of the estimation are chosen after several tests, being the number of composites to be used for the estimates and the best number for the 8 estimation sectors. A treatment of outliers was applied for samples for domains with less than 100 composites. These had no top cut applied however had the search radius reduced to 20 m for outliers above the determined limits.

The search radii are related to the semi-variogram ranges for first and second runs with the third using a larger neighbourhood to fill blocks not estimated within the lodes. The orientation of the search ellipsoid was based on the orientation of the individual lodes. A summary of the estimation parameters by neighbourhood are follows:

1st neighbourhood: search radius 35 m x 30 m x 15 m. Minimum number of samples = 4, maximum number of samples = 32, 8 sectors and a minimum 3 drillholes around a 120° spaced, 3D continuity.
2nd neighbourhood: search radius 70 m x 60 m x 30 m. Minimum number of Samples = 4, maximum number of samples = 32, octant search and a minimum of 2 drillholes around 180° spaced, 2D continuity.

3rd neighbourhood: The search ellipsoid to estimate remain blocks within the lode wireframe. Search radius 500 m x 500 m x 100 m. Minimum of 1 Sample and a maximum of 4 samples. Details of the search orientation for each lode domain are detailed in Table 14.41.

amcconsultants.com

125

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.41 Urucum South Underground model: orientation of search radius of individual lodes

Lode code VarSector No blocks Az Dip Plunge   Lode code VarSector No blocks Az Dip Plunge
LOCS800 350to360_55to70E 80 -10 70 10   LOUN600 350to360_35to50E 37 -5 50 0
LOCS801 350to360_55to70E 110 -10 70 10   LOUN601 350to360_55to70E 157 -5 55 10
LOCS802 335to340_55to70E 67 -20 60 10   LOUN602 350to360_0to30E 281 -5 30 0
LOCS803 350to360_55to70E 34 0 70 10   LOUN603 350to360_35to50E 135 -5 45 0
LOCS804 350to360_55to70E 218 -10 70 10   LOUN605 350to360_35to50E 67 -5 40 0
LOUS902 350to360_55to70E 1,133 0 55 10   LOUN606 350to360_35to50E 119 -5 45 0
LOUS903 350to360_55to70E 1,441 -10 60 10   LOUN607 350to360_35to50E 12 0 50 0
LOUS904 350to360_55to70E 319 -5 65 10   LOUN608 350to360_75to90E 62 -5 80 10
LOUS905 350to360_0to25W 68 -20 -10 0   LOUN609 350to360_55to70E 29 -5 55 10
LOCN700 350to360_0to25W 2,330 0 -15 0   LOUN610 335to340_55to70E 23 -20 60 10
LOCN701 350to360_55to70E 245 0 70 10   LOUN612 350to360_35to50E 3 0 40 0
LOCN702 350to360_55to70E 5,606 -10 70 10   LOUN614 350to360_75to90E 74 -10 75 10
LOCN704 350to360_55to70E 2,888 -10 70 10   LOUN615 350to360_75to90E 61 0 85 10
LOCN706 350to360_75to90E 74 -10 75 10   LOUN616 335to340_55to70E 16 -20 60 10
LOCN708 350to360_55to70E 48 0 60 10   LOUN617 350to360_35to50E 25 0 -40 0
LOCN709 350to360_35to50E 79 0 35 0   LOUN618 335to340_55to70E 22 -20 60 10
LOCN710 350to360_75to90E 29 -5 80 10   LOUN620 350to360_0to30E 3 0 30 0
LOCN711 350to360_55to70E 31 0 60 10   LOUN621 350to360_55to70E 6 -5 60 10
LOCN712 350to360_75to90E 38 0 90 10   LOUN623 350to360_0to25W 8 0 -25 0
LOCN713 350to360_0to30E 16 0 25 0   LOUN624 350to360_55to70E 5 0 55 10
LOCN715 350to360_0to25W 26 0 -25 0   LOUN625 350to360_35to50E 5 0 45 0
LOCN716 350to360_55to70E 39 0 60 10   LOUN626 350to360_0to25W 129 0 -25 0
LOCN717 335to340_55to70E 44 -20 70 10   LOUN627 350to360_75to90E 82 0 85 10
LOCN718 350to360_55to70E 57 0 70 10   LOUN628 350to360_75to90E 45 10 85 10
LOCN719 350to360_75to90E 42 0 80 10   LOUS900OX 350to360_55to70E 180 -10 60 10
LOCN720 350to360_55to70E 23 -20 -65 10   LOUS900FR 350to360_55to70E 441 -10 60 10
LOCN722 350to360_0to25W 28 0 -5 0   LOUS901OX 335to340_55to70E 103 -25 60 10
LOLN001 350to360_75to90E 7,171 -5 80 10   LOUS901FR 335to340_55to70E 176 -25 60 10
LOLN002 350to360_75to90E 5,480 -5 80 10   LOCN703OX 350to360_55to70E 481 -5 70 10
LOLN299 350to360_75to90E 2,685 -5 80 10   LOCN703FR 350to360_55to70E 1498 -5 70 10
LOLN300 350to360_75to90E 5,827 -5 80 10   LOCN705OX 350to360_55to70E 48 -5 70 10

 

amcconsultants.com

126

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Lode code VarSector No blocks Az Dip Plunge   Lode code VarSector No blocks Az Dip Plunge
LOLN301 350to360_75to90E 3,109 0 80 10   LOCN705FR 350to360_55to70E 97 -5 70 10
LOLN400 350to360_75to90E 2,950 -5 80 10   LOCN707OX 335to340_55to70E 72 -20 55 10
LOLN500 350to360_75to90E 149 0 80 10   LOCN707FR 335to340_55to70E 44 -20 55 10
LOUN510 350to360_0to25W 2,229 25 -15 0   LOCN721OX 350to360_0to30E 80 0 0 0
LOUN530 350to360_0to25W 201 0 -15 0   LOCN721FR 350to360_0to30E 51 0 0 0
LOUN540 350to360_0to25W 322 0 -15 0   LOUN520OX 350to360_0to25W 404 0 -15 0
LOUN550 350to360_0to25W 85 5 -30 0   LOUN520FR 350to360_0to25W 228 0 -15 0
    LOUN613OX 350to360_75to90E 49 -10 80 10
  LOUN613FR 350to360_75to90E 57 -10 80 10

Notes:

Azimuth Negative = Northwest quadrant

Dip Negative = Southwest quadrant

Plunge Negative = South quadrant

VarSector = Variogram sector

 

amcconsultants.com

127

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.7.4.1Urucum South Underground model - estimate validation

 

The statistical validation of estimated grades consisted in a comparison of these grades by neighbourhood (“NN”) and lode with the sample mean grades, NN estimated grades and the slope of regression.

The Swath Plot analysis was applied to validate the grades along the block model in 3 main directions: X, Y, and Z. The procedure involved a comparison between the sample mean grade, OK estimated grade, and NN estimated grade along slices. A high difference with a large number of samples indicates a problem with estimation process and requires further investigation. In all cases there was a reasonable correlation of samples and the block model grades especially in the Measured and Indicated regions. There were some differences however these related to Inferred blocks and small number of blocks and samples.

14.7.5Urucum East model-OK estimation

Traditional 3D OK in Surpac software was used to interpolate gold into Y = 10 m x X = 5 m x Z = 2 m parent cells for all Urucum East mineralized domains. All domains were estimated individually using the uniquely coded 1 m downhole composite data. Urucum East estimation parameters are summarized in Table 14.42.

Table 14.42 Urucum East summary estimation parameters

Parameter HG zone Colluvium
Minimum number of composites 3 4
Maximum number of composites 20 24
Search major distance 76 155
Search orientation 0 0
Plunge of major axis -30 0
Dip of major axis 0 0
Anisotropy major / semi-major 1.44 1
Anisotropy major / minor 10 1
Block discretization 3x2x2 3x2x2
14.7.5.1Estimate validation

A variety of validation checks on the final estimated block model were undertaken. The validation checks included swath plots and visual inspection.

Swath plots were used to detect any obvious spatial biases between the OK estimates and the informing composites. As expected, in the swath plots the OK estimates are somewhat more smoothed than the raw composite grades. Some minor local discrepancies exist (e.g. 403,030 mE), however excluding these there is little evidence of obvious spatial bias.

A visual validation was undertaken of composite grades and estimated model for all estimated domains. It was concluded that the grade estimation process adequately reflects the input data.

14.7.6Tap C (other) estimation

Gold block grades are estimated by OK performed using parent cells, sample composites within hard boundaries, and estimation based on the variography of domains grouped by variogram sectors.

amcconsultants.com

128

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The key parameters of the estimation were chosen after several tests. A critical parameter was the number of composites to be used for the estimates and the best number for each sector. The choice was guided by optimizing the slope of regression.

The kriging took place in three successive runs with the search radii related to the semi-variogram ranges and the third run using an increasingly larger neighbourhood to fill in the blocks not estimated within the mineralization wireframes. The search ellipses are generally orientated in the same direction as the variogram’s anisotropic axes.

Typically, the search ellipse is divided in eight octants, and an optimum number of four data points per octant is sought (i.e. 32 data points in total). In the first run, a minimum of four data points in total was required for the block to be estimated. This condition is relaxed to one in subsequent runs.

1st neighbourhood represents the distance of 70% to 80% of Sill, the distance of the main inflection of the semi-variogram, minimum number of samples 4, Maximum 32, octants search and a minimum of 2 drillholes to estimate a block. Blocks estimated in this search strategy were classified as Measured.
2nd neighbourhood represents the distance of 100% of Sill, minimum number of samples 2, maximum 16, octant search and a minimum of 2 drillholes to estimate a block. Restrictions were applied to the search radius for high grade values. Blocks estimated in this search strategy were classified as Indicated
3rd neighbourhood represents the search ellipsoid to estimate remain blocks, sectors North and South: U = 720; V = 240; W = 80; minimum of 1 Sample, maximum of 4. Restrictions were applied to the search radius for high grade values. Blocks estimated in this search strategy were classified as Inferred.

The quality of the OK is variable based on the criteria of the slope of regression. Many blocks were poorly estimated, mostly due to the paucity of data in some areas and the relatively poor grade continuity, and consequently the grades could be smoothed. It is suggested to implement a closer spaced drilling in grade-smoothed areas to reduce this effect.

14.7.6.1Estimate validation

The statistical validation of Au estimated grades (g/t) was undertaken by a comparison of these grades estimated in each neighbourhood against the sample mean grade, nearest neighbourhood estimated grades and the slope of regression, separated by lode.

Table 14.43 gives an example for the first neighbourhood.

This comparison was carried out to gain an understanding of the performance of the OK estimation allowing for some parameter adjustments of each neighbourhood and to obtain information of the number of estimated blocks. This work assisted in defining cut-offs for high grade transition (e.g. reduced search ellipsoid to 20 m for Au (g/t) greater than the defined COG). The overall aim was to avoid excessive smoothing of grades and control the differences so as to not exceed 10%.

amcconsultants.com

129

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.43 Statistical validation of Au (g/t) of 1st neighbourhood

Lode_type No blocks Statistics of Au estimated blocks (g/t) Au grades to control estimation (g/t) Percentile
Samp index Block index Total Estimated Percent Count Mean grade Mean slope Mean slope 2M CMP No capping

2M CMP

capping

Dif

Krig / CMP

LODE3_4_5101 EX_LODE3_4_5101 8,121 3,276 40.34% 3,276 0.870 0.713 0.713 0.919 1.003 -13.2% 9.2%
LODE102 EX_LODE102 3,770 659 17.48% 659 1.345 0.659 0.659 1.543 1.594 -15.6% 3.3%
LODE111 EX_LODE111 1,681 499 29.68% 499 0.915 0.644 0.644 1.054 1.095 -16.4% 3.9%
LOGR020 EX_LOGR020 1,262 153 12.12% 153 0.687 0.523 0.523 0.679 0.715 -4.0% 5.3%
LODE103 EX_LODE103 130 45 34.62% 45 0.651 0.545 0.545 0.710 0.710 -8.3% 0.0%
LODE104 EX_LODE104 207 32 15.46% 32 0.708 0.714 0.714 0.709 0.709 -0.2% 0.0%
LODE105 EX_LODE105 80 28 35.00% 28 0.543 0.721 0.721 0.537 0.537 1.1% 0.0%
LODE108 EX_LODE108 343 71 20.70% 71 0.526 0.572 0.572 0.549 0.549 -4.3% 0.0%
LODE107 EX_LODE107 126 21 16.67% 21 1.052 0.787 0.787 1.089 1.106 -4.9% 1.5%
LODE106 EX_LODE106 443 130 29.35% 130 1.574 0.783 0.783 1.715 1.807 -12.9% 5.4%
LODE109 EX_LODE109 604 89 14.74% 89 0.969 0.615 0.615 0.996 0.996 -2.7% 0.0%
LODE110 EX_LODE110 514 126 24.51% 126 0.879 0.716 0.716 0.870 0.908 -3.2% 4.4%
LGEV3_4_5010 EX_LGEV3_4_5010 11,309 4,254 37.62% 4,254 0.193 0.381 0.381 0.196 0.214 -10.0% 9.2%
LODE2101 EX_LODE2101 2,895 2,110 72.88% 2,110 1.450 0.768 0.768 1.425 1.486 -2.5% 4.3%
LGEV2010 EX_LGEV2010 4,840 2,047 42.29% 2,047 0.502 0.543 0.543 0.522 0.559 -10.2% 7.1%
Total   36,325 13,540 37.27% 13,540 0.719 0.583 0.583 0.747 0.794 -9.5% 6.3%

 

amcconsultants.com

130

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Swath plot analysis was undertaken to validate the block model grades in 3 main directions: X, Y, and Z. The procedure involved a comparison of sample mean grade, OK estimated grades, nearest neighbourhood estimated grades in each direction. If the difference compared to the block mean is high with a large number of samples then the estimation process has problems and needs to be revised. In all cases there was observed a reasonable correlation of samples and block model grades, especially in the Measured and Indicated regions. There were noted some differences but these related to Inferred blocks and a small number of blocks and samples.

14.7.7Tap C Model (Tap C3N and Tap C3W areas)

Estimation of the Tap C 31 (Tap C3N and C3W) update was principally carried out on 3 grouped domains. The groupings were determined by domain orientation and location. Estimation was carried out by OK in Surpac software using the mineralization wireframes as hard boundaries. The estimation was carried out in 2 passes, the first to the maximum range of the variogram and the second extended to fill the lode solid. An elliptical search was used with a minimum of 3 and maximum of 15 samples used to inform the estimation in both passes. OK parameters used for each domain are detailed in Table 14.44 below.

Table 14.44 Estimation parameters for Tap C (Tap C3N and Tap C3W areas)

     

Sill

(relative

variance)

Range Azimuth Plunge Dip

Major /

semi major

ratio

Major /

minor

ratio

Zone 1

Moderate

East

Dipping

Lodes

Nugget 0.38            
S 1 0.02 18.9 0 0 -50 1.4 0.9
S 2 0.07 112.7 0 0 -50 1.9 1.9
Zone 2

Flat W

Dipping

Lodes

Nugget 0.26            
S 1 0.08 15.8 0 0 10 0.6 0.6
S 2 0.04 79.5 0 0 10 1.2 2.7
Zone 7

Flat

Dipping

Lodes

Nugget 0.22            
S 1 0.02 46.7 0 0 0 1.4 5.5
S 2 0.10 94.3 0 0 0 1.1 3.3
14.7.8Stockpile estimation

Stockpiles are calculated on a monthly basis by balancing mass and metal of the survey reconciled mine production, mill throughput, and previous end of month stockpiles. The mine production is estimated using the grade control model for gold and the resource model for density. As-mined, adjusted dig polygons, and end of month survey pickups are used to obtain mined ore volumes which are then interrogated with the grade control model to determine tonnes and grade.

Ore categories are divided on the basis of grade range (Very High Grade, High Grade, Low Grade, and Marginal; see Table 16.6) and material type (Oxide or Sulphide). The survey reconciled mine production is distributed to the various intermediary "live" stockpiles located proximal to active pit areas and the ROM stockpiles on the basis of these categories. Tallied truck tonnes are compared against the survey reconciled production to check for any discrepancies between actual material movement and the polygons mined. Ore movement from live stockpiles to the ROM during the month is also determined as part of the distribution of monthly mine production, to its final destination.

Daily stockpile blending on the ROM is adjusted to plant reconciled total dry tonnes and grade for the month. The monthly stockpile balance for both mass and Au metal is then undertaken as follows; Opening Stockpile + Survey Reconciled Production = Mill Throughput + Closing Stockpile. Each stockpile is surveyed at the end of month and the balance of the mass and metal checked against the stockpile volume to ensure that swelled density is within the acceptable range for the material type.

amcconsultants.com

131

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Spent Ore from the previous heap leach operation is periodically added to the blend. The mass and grade of the Spent Ore has been determined from a grade control model based initially on a RC drilling pattern of 40 m x 40 m grid and later a 20 m x 20 m grid. Density was determined with 52 density test pits completed across the deposit. Both the pre-mining total tonnage and grade of Spent Ore from the model was a close match with the final estimate of Spent Ore tonnes and grade determined by MPBA plant metallurgists at the closure of the heap leach. The tonnes and grade of Spent Ore remaining in the stockpile is calculated from the grade control model and both the pre-mining and end of month topographic surfaces.

14.7.9Duckhead estimation

Gold grades are estimated by three consecutive OK runs performed using parent cells of dimensions 5 m x 10 m x 2 m (x, y, z), hard boundaries and 2 m composites. The key parameters for the estimation were selected, with the critical parameter being the number of composites to be used and the optimal number of composites per sector in the octant search. The search radii are related to the semi-variogram ranges for first and second estimation runs, for the third a large neighbourhood was used to fill the not estimated blocks with the orientation, based on that individual domains. The summary of the search neighbourhood parameters is following:

1st neighbourhood with search radius value varying according to fit 85% to 90% of the sill of the variograms, minimum number of samples 4, Maximum 32, 8 sectors and Minimum 3 drillholes in a grid of 120° spaced - 3D continuity.
2nd neighbourhood search radius 2x Neighbourhood 1, minimum number of Samples 4, Maximum 32, octants and minimum 2 drillholes - 2D continuity
3rd neighbourhood represents the search ellipsoid to estimate remain blocks, 1,500 m x 1,500 m x 100 m; minimum of 1 Sample, maximum of 4.

Table 14.45 below shows the Duckhead search ellipses by oxidation domain.

amcconsultants.com

132

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.45 Duckhead search ellipses by lode / oxidation domain

Rock codes VarSector No blocks

High grade

transition

Az Dip 1st neigh 2nd neigh 3rd neigh
Dist X Dist Y Dist Z Dist X Dist Y Dist Z Dist X Dist Y Dist Z
LODE1 1 LODE1 595 999.0 Yes 95 60 20 45 20 40 100 40 1,000 1,000 100
LODE100 100 LOWDIP 521 999.0 Yes 125 15 30 30 10 60 100 20 1,000 1,000 100
LODE101 101 LOWDIP 1,263 1.5 Yes 105 10 30 30 10 60 100 20 1,000 1,000 100
LODE102 102 LOWDIP 895 999.0 Yes 115 15 30 30 10 60 100 20 1,000 1,000 100
LODE103 103 LOWDIP 101 999.0 Yes 125 15 30 30 10 60 100 20 1,000 1,000 100
LODE104 104 LOWDIP 36 999.0 Yes 125 15 30 30 10 60 100 20 1,000 1,000 100
LODE105 105 LOWDIP 34 999.0 Yes 125 15 30 30 10 60 100 20 1,000 1,000 100
LODE106 106 LOWDIP 1,015 2.0 Yes 125 15 30 30 10 60 100 20 1,000 1,000 100
LODE107 107 LOWDIP 2,122 999.0 Yes 110 15 30 30 10 60 100 20 1,000 1,000 100
LODE108 108 HIGHDIP 3,295 999.0 Yes 135 70 30 50 15 60 100 30 1,000 1,000 100
LODE109 109 HIGHDIP 219 1.5 Yes 140 60 30 50 15 60 100 30 1,000 1,000 100
LODE2 2 LODES2_4_6 2,478 999.0 Yes 100 70 30 30 10 60 100 20 1,000 1,000 100
LODE3 3 HIGHDIP 3,716 999.0 Yes 110 70 30 50 15 60 100 30 1,000 1,000 100
LODE31 31 LOWDIP 2,381 999.0 Yes 125 45 30 30 10 60 100 20 1,000 1,000 100
LODE71 71 HIGHDIP 1,298 999.0 Yes 120 75 30 50 15 60 100 30 1,000 1,000 100
LODE8 8 HIGHDIP 1,062 999.0 Yes 115 85 30 50 15 60 100 30 1,000 1,000 100
LODE9 9 LOWDIP 3,122 999.0 Yes 110 10 30 30 10 60 100 20 1,000 1,000 100
LODE90 90 LOWDIP 2,675 3.5 Yes 135 25 30 30 10 60 100 20 1,000 1,000 100
LODE110OX 3110 HIGHDIP 1,538 2.5 Yes 115 70 30 50 15 60 100 30 1,000 1,000 100
LODE110FR 5110 HIGHDIP 1,583 2.5 Yes 115 70 30 50 15 60 100 30 1,000 1,000 100
LODE4OX 3004 LODES2_4_6 1,348 999.0 Yes 120 70 30 30 10 60 100 20 1,000 1,000 100
LODE4FR 5004 LODES2_4_6 1,383 999.0 Yes 120 70 30 30 10 60 100 20 1,000 1,000 100
LODE5OX 3005 HIGHDIP 1,806 999.0 Yes 120 70 30 50 15 60 100 30 1,000 1,000 100
LODE5FR 5005 HIGHDIP 1,976 999.0 Yes 120 70 30 50 15 60 100 30 1,000 1,000 100
LODE51OX 3051 HIGHDIP 239 999.0 Yes 125 70 30 50 15 60 100 30 1,000 1,000 100
LODE51FR 5051 HIGHDIP 768 999.0 Yes 125 70 30 50 15 60 100 30 1,000 1,000 100
LODE6OX 3006 LODES2_4_6 66 8.0 Yes 130 70 30 30 10 60 100 20 1,000 1,000 100
LODE6FR 5006 LODES2_4_6 147 8.0 Yes 130 70 30 30 10 60 100 20 1,000 1,000 100
LODE7OX 3007 HIGHDIP 749 999.0 Yes 115 70 30 50 15 60 100 30 1,000 1,000 100
LODE7FR 5007 HIGHDIP 3,980 999.0 Yes 115 70 30 50 15 60 100 30 1,000 1,000 100

VarSector = Variogram Sector, Dist = Distance

 

amcconsultants.com

133

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

14.8Depletion for mining activity

 

Depletion to account for mining activity has been applied to the models. Depletion has been applied as of 30 June 2017 via the use of surveyed topographic surfaces as at that date. Depletion has been applied by block model flag to identify the mined and in-situ portions of the models.

14.9Resource classification

Resource classification was completed based on an assessment of the following criteria:

Geological knowledge and interpretation.
Data distribution including drilling density and orientation.
Variogram models and the ranges of the first structure in multi-structure models.
Estimation statistics.

The model was inspected visually, and manual adjustments made where appropriate.

Table 14.46 describes the criteria used to classify each deposit.

 

 

amcconsultants.com

134

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.46 Resource classification criteria

Deposit Measured Indicated Inferred Notes
Urucum Open Pit

- Blocks insitu (not mined)

- Blocks estimated in pass 1

- Distance to nearest data ≤ 20 m

- Average distance to samples ≤ 35 m

- ≥ 24 data used from ≥ 9 drillholes

- Blocks insitu (not mined)

- Blocks estimated in pass 1 or 2

- Average distance to samples ≤ 75 m

- ≥ 24 data used from ≥ 9 drillholes

- All other insitu blocks (not mined)  
Tap AB Open Pit

- Blocks insitu (not mined)

- Blocks estimated in pass 1

- Distance to nearest data ≤ 15 m

- 24 data used from ≥ 7 drillholes

- Blocks insitu (not mined)

- Blocks estimated in pass 1 or 2

- Average distance to samples ≤ 60 m

- ≥ 24 data used from ≥ 9 drillholes

- All other insitu blocks (not mined)  
Tap AB Underground

- Blocks estimated by ≥ 3 drillholes in pass 1

- minimum number of samples required

- Blocks estimated with ≥ 2 and ≤ 16 samples in octant search

- minimum 2 drillholes

- All other blocks

Moving average post processing

applied to individual blocks.

Grouped on panels lode thickness x

60 m in North direction15m in Z

direction to minimize spottiness of classification

Urucum North Underground Lode 1 (Ore shoots 1001-1004) - Slope of regression > 0.7 - Slope of regression 0.4 to 0.7 - Slope of regression < 0.4

Classified based on geological

knowledge of lode/ore shoot, drill

grid and slope of regression,

subsequent visual inspection and

manual adjustment

Lode 2 (Ore shoots 2001-2003, 2005) - Slope of regression > 0.7 - Slope of regression 0.4 to 0.7 - Slope of regression < 0.4
Lode 300 (Ore shoot 3001-3005) - Slope of regression > 0.7 - Slope of regression 0.4 to 0.7 - Slope of regression < 0.4
Lode 400 (Ore shoot 4001-4002, 4005) - Slope of regression > 0.7 - Slope of regression 0.4 to 0.7 - Slope of regression < 0.5
Lode 100, 299, 301 N / A N / A N / A Adjusted to be unclassified
Lode 500 N / A N / A   Manually classified as inferred
Urucum East 2013 N / A

- Drill spacing sufficient to

demonstrate confidence in geometry

and continuity of grade

- Blocks within 30 m of sample

- Infill drilling required

- Blocks between 30 and

76 m from sample

Blocks <76 m from sample not

classified. Applied to both mineralized lode and colluvium

domains.

Tap C (other)

- At least 3 drillholes in first pass

- minimum number of samples used in kriging

- Blocks estimated with ≥ 2 and ≤ 16

samples in octant search

- minimum 2 drillholes

- All other blocks

Distribution of data, number of

samples used to estimate the block

and range of the semi-variogram.

Slope of regression was used to validate.

Tap C (Tap C3N and C3W areas) - Average distance to sample <20 m Average distance to sample <5 0m

- All other blocks within

domain wireframe.

 

 

 

amcconsultants.com

135

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Figure 14.13 shows an example of the resource classification for the Urucum East model.

Figure 14.13 Urucum East Model - resource classification - HG Lode

Note: Green = Indicated, Purple = Inferred.

Source: BDR

14.10Resource reporting

The summary total Mineral Resource for the Tucano Gold Project is provided as of 30 June 2017 in Table 14.47 below. The COG for reporting is 0.5 g/t Au for open pit resources and most stockpiles and 1.2 g/t Au for underground resources. In view of the nature and style of the mineralization and potential mining approach and method, this is considered an appropriate COG. It should be noted that Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

The Mineral Resources have been estimated in accordance with Canadian National Instrument 43-101 “Standards of Disclosure for Mineral Projects” ("NI 43-101") of August 2011 and “Definition Standards for Mineral Resources and Mineral Reserves” adopted by the CIM Council on May 2014. Measured and Indicated Mineral Resources are inclusive of those Mineral Resources modified to produce the Mineral Reserves.

amcconsultants.com

136

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.47 Tucano Gold Resources 30 June 2017

Brazil Cut-off Measured Indicated Total Measured & Indicated Inferred
Au (g/t) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000)
Urucum Open Pit oxide 0.5 678 1.15 25 344 1.08 12 1,021 1.13 37 70 0.97 2.16
Urucum East Open Pit oxide 0.5 0 0.00 0 200 1.88 12 200 1.88 12 9 1.58 0.44
Tap AB Open Pit oxide 0.5 2,870 2.18 201 3,889 1.76 220 6,759 1.94 421 796 1.11 28.47
Tap C Open Pit oxide 0.5 566 0.97 18 312 0.90 9 878 0.95 27 88 0.70 1.99
Duckhead Open Pit oxide 1 89 4.24 12 140 1.74 8 229 2.71 20 60 1.56 3.01
Total oxide   4,202 1.90 256 4,885 1.66 261 9,087 1.77 517 1,022 1.10 36.07
Urucum Open Pit primary 0.5 5,783 1.54 286 7,120 1.71 393 12,903 1.63 678 393 1.57 20.00
Urucum East Open Pit fresh 0.5 0 0.00 0 211 1.45 10 211 1.45 10 84 0.94 3.00
Tap AB Open Pit primary 0.5 2,356 1.74 132 4,176 1.57 210 6,531 1.63 342 1,053 1.34 45.00
Tap C Open Pit primary 0.5 482 1.22 19 1,980 1.22 78 2,462 1.22 97 1,044 1.35 45.00
Duckhead surface primary 1 115 2.28 8 264 2.26 19 379 2.26 28 262 1.81 15.00
Open Pit primary   8,736 1.58 445 13,750 1.60 709 22,486 1.60 1,154 2,837 1.41 128.00
Urucum Open Pit total 0.5 6,460 1.50 311 7,464 1.69 404 13,924 1.60 715 463 1.48 21.97
Urucum East Open Pit total 0.5 0 0.00 0 411 1.66 22 411 1.66 22 92 1.00 2.97
Tap AB Open Pit total 0.5 5,225 1.98 333 8,065 1.66 430 13,290 1.79 764 1,849 1.24 73.86
Tap C Open Pit total 0.5 1,048 1.09 37 2,292 1.18 87 3,340 1.15 123 1,133 1.30 47.32
Duckhead Open Pit total 1 205 3.14 21 404 2.08 27 608 2.43 48 322 1.76 18.25
Total oxide & primary open pit   12,938 1.69 701 18,635 1.62 970 31,573 1.65 1,671 3,859 1.32 164.37
Open pit stockpile 0.5 1,985 0.66 42 0 0.00 0 1,985 0.66 42 0 0.00 0.00
Spent ore stockpile 0.5 1,311 0.61 26 0 0.00 0 1,311 0.61 26 0 0.00 0.00
Rom expansion stockpile 0.5 345 0.80 9 0 0.00 0 345 0.80 9 0 0.00 0.00
Marginal ore stockpiles 0.3 1,586 0.44 22 0 0.00 0 1,586 0.44 22 0 0.00 0.00
Total stockpiles   5,228 0.59 99 0 0.00 0 5,228 0.59 99 0 0.00 0.00
Total Tucano Open Pit & stockpiles   18,166 1.37 800 18,635 1.62 970 36,801 1.50 1,770 3,859 1.32 164.37
Tap AB Underground primary* 1.2 22 1.49 1 1,025 2.3 76 1,047 2.28 77 3,653 3.19 375
Urucum Underground primary - pfs 1.6 260 4.06 34 2,634 4.24 359 2,894 4.22 393 5,106 2.71 445
Urucum Underground primary - non pfs 1.2 0 0.00 0 0 0 0 0 0.00 0 3,733 1.38 166
Total Tucano Underground   282 3.86 35 3,659 3.70 435 3,941 3.71 470 12,492 2.45 986
Grand total Tucano   18,448 1.41 835 22,293 1.96 1,405 40,742 1.71 2,240 16,351 2.19 1,150

Notes:

* The June 2017 Tap AB UG Resource includes 173 kt at 4.68 g/t Au of Inferred Oxide within the Inferred Primary Category.

CIM Definition Standards (2014) were used for reporting the Mineral Resources.
Mr B. Wolfe, MAIG is the Qualified Person under NI 43-101 and takes responsibility for the Mineral Resource estimate for the Tap AB Open Pit and Urucum Open Pit Resource. Mr M. Batelochi, MAusImm (CP) is the Qualified Person under NI 43-101 and takes responsibility for all remaining resources.
Tap AB and Urucum Open Pit Mineral Resources are constrained by an optimized pit shell at a gold price of US$1,500 oz. The COG applied to the open pit resources is 0.5 g/t Au. The COG applied to ore stockpiles is 0.5 g/t Au with the exception of Marginal Ore which has a COG of 0.3 g/t Au.
The underground COG is 1.2 g/t Au.
Drilling results up to 30 June 2017 for the Tap AB Open Pit resource and 31 December 2016 for all other deposits.
Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
The numbers may not compute exactly due to rounding.

 

 

amcconsultants.com

137

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

14.11Comparison with previous estimates.

  

The previous Mineral Resource estimate on the Property was published in a BDR ASX announcement “Ore Reserve and Mineral Resource Update” dated 11 April 2017. The previous Mineral Resources had an effective date of 31 December 2016.

Table 14.48 shows the Mineral Resource changes by deposit and physical reporting limits. Note that many deposits are unchanged since the 2016 estimate.

 

 

 

amcconsultants.com

138

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.48 Mineral Resource changes by deposit and physical reporting limits

Deposit Pit area Mine method Estimation method Previous effective resource date Current effective resource date Change from previous to current effective date Physical limits for resource reporting
Urucum

Urucum

North

Open Pit

(Surface)

MIK and OK 31 Dec 2016 30 June 2017 Model Re-reported Only. North of 99,300 mN and above the US$1,100, 31 Dec 2016 reserve pit design. Also included is near surface resource located outside of the reserve pit and inside of the US$1,500 Measured + Indicated + Inferred (MII) optimized pit shell which does not form part of the Urucum North Underground Resources.
Urucum

Urucum

South

Open Pit

(Surface)

MIK and OK 31 Dec 2016 30 June 2017 No Change South of 99,300 mN and above the 31 Dec 2016 US$1,500 MII optimized pit shell.
Urucum

Urucum

North

Underground OK 31 Dec 2016 30 June 2017 No Change North of 99,300 mN and below 31 Dec 2016 reserve pit design (based on US$1,100 MII optimized pit shell).
Urucum

Urucum

South

Underground OK 31 Dec 2016 30 June 2017 No Change South of 99,300 mN and below the 31 Dec 2016 US$1,500 MII optimized pit shell.
Urucum

Urucum

East

Open Pit

(Surface)

OK 31 Dec 2016 30 June 2017 No Change No Pit Shell Reporting Limit Applied.
Tap C Tap C

Open Pit

(Surface)

OK 31 Dec 2016 30 June 2017 No Change No Pit Shell Reporting Limit Applied.
Tap AB Tap AB

Open Pit

(Surface)

MIK and OK 31 Dec 2016 30 June 2017 Model Re-estimated and Reported Above the 30 June 2016 US$1,500 MII optimized pit shell.
Tap AB Tap AB Underground OK 31 Dec 2016 30 June 2017 Model Re-reported Only Below the 30 June 2016 US$1,500 MII optimized pit shell.
Duckhead Duckhead

Open Pit

(Surface)

OK 31 Dec 2016 30 June 2017 No Change No Pit Shell Reporting Limit Applied.

 

 

amcconsultants.com

139

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

 

Changes to the Mineral Resource estimated in this report are due predominately to:

Additional drilling completed within the Tap AB optimized resource pit shell completed between the 31 December 2016 and 30 June 2017 resource estimates.
Re-optimization of the Tap AB US$1,500 MII shell used to constrain the Tap AB Open Pit Resource and Tap AB Underground Resource as at 30 June 2017.
The 31 December 2016 Mineral Resource estimate for Urucum North Open Pit resource included shallow, near surface Mineral Resources occurring outside of the US$1,500 MII Optimized Pit Shell and north of 99,300 mN. These resources were removed in the 30 June 2017 reported resources.
31 December 2016 Tap AB Underground Mineral Resources in the Measured and Indicated category were classified to Inferred by reason that a PFS had not been undertaken to determine viability of the underground resource. The 30 June 2017 resource has reported from the same model using the original geostatistical resource classification and not converting these Measured and Indicated Resources to Inferred Resource.
Mining depletion of the Tap AB Open Pit Resource and Open Pit Stockpiles between 31 December 2016 and 30 June 2017.
Conversion of part of the Open Pit Stockpile to the new ROM Expansion Stockpile.
Increase in Marginal Stocks not processed by the plant.

Table 14.49 shows the comparison to the previous estimate.

amcconsultants.com

140

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 14.49 Comparison of Mineral Resource estimates

Brazil Cut-off Measured - 31 Dec 2016 Measured - 30 June 2017 Indicated - 31 Dec 2016 Indicated - 30 June 2017 Total Measured & Indicated - 31 Dec 2016 Total Measured & Indicated - 30 June 2017 Inferred - 31 Dec 2016 Inferred - 30 June 2017
Au (g/t) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000)
Urucum Open Pit oxide 0.5 713 1.13 26 678 1.15 25 409 1 13 344 1.08 12 1,122 1.08 39 1,021 1.13 37 87 0.9 3 70 0.97 2
Urucum East Open Pit oxide 0.5 0 0 0 0 0 0 200 1.88 12 200 1.88 12 200 1.88 12 200 1.88 12 9 1.58 0 9 1.58 0
Tap AB Open Pit oxide 0.5 2,980 2.05 197 2,870 2.18 201 4,559 1.94 285 3,889 1.76 220 7,540 1.99 481 6,759 1.94 421 1,228 1.58 62 796 1.11 28
Tap C Open Pit oxide 0.5 566 0.97 18 566 0.97 18 312 0.9 9 312 0.9 9 878 0.95 27 878 0.95 27 88 0.7 2 88 0.7 2
Duckhead Open Pit oxide 1 89 4.24 12 89 4.24 12 140 1.74 8 140 1.74 8 229 2.71 20 229 2.71 20 60 1.56 3 60 1.56 3
Total oxide   4,348 1.81 252 4,202 1.9 256 5,621 1.81 327 4,885 1.66 261 9,969 1.81 579 9,087 1.77 517 1,472 1.49 70 1,022 1.1 36
Urucum Open Pit primary 0.5 5,822 1.53 287 5,783 1.54 286 7,184 1.71 395 7,120 1.71 393 13,007 1.63 682 12,903 1.63 678 410 1.53 20 393 1.57 20
Urucum East Open Pit primary 0.5 0 0 0 0 0 0 211 1.45 10 211 1.45 10 211 1.45 10 211 1.45 10 84 0.94 3 84 0.94 3
Tap AB Open Pit primary 0.5 2,155 1.78 123 2,356 1.74 132 4,233 1.81 247 4,176 1.57 210 6,388 1.8 370 6,531 1.63 342 2,804 1.62 146 1,053 1.34 45
Tap C Open Pit primary 0.5 482 1.22 19 482 1.22 19 1,980 1.22 78 1,980 1.22 78 2,462 1.22 97 2,462 1.22 97 1,044 1.35 45 1,044 1.35 45
Duckhead surface primary 1 115 2.28 8 115 2.28 8 264 2.26 19 264 2.26 19 379 2.26 28 379 2.26 28 262 1.81 15 262 1.81 15
Open Pit primary   8,575 1.59 437 8,736 1.58 445 13,872 1.68 749 13,750 1.6 709 22,447 1.64 1,186 22,486 1.6 1,154 4,604 1.55 229 2,837 1.41 128
Urucum Open Pit total 0.5 6,535 1.49 313 6,460 1.5 311 7,594 1.67 408 7,464 1.69 404 14,129 1.59 721 13,924 1.6 715 497 1.42 23 463 1.48 22
Urucum East Open Pit total 0.5 0 0 0 0 0 0 411 1.66 22 411 1.66 22 411 1.66 22 411 1.66 22 92 1 3 92 1 3
Tap AB Open Pit total 0.5 5,135 1.94 320 5,225 1.98 333 8,792 1.88 532 8,065 1.66 430 13,928 1.9 852 13,290 1.79 764 4,032 1.61 208 1,849 1.24 74
Tap C Open Pit total 0.5 1,048 1.09 37 1,048 1.09 37 2,292 1.18 87 2,292 1.18 87 3,340 1.15 123 3,340 1.15 123 1,133 1.3 47 1,133 1.3 47
Duckhead Open Pit total 1 205 3.14 21 205 3.14 21 404 2.08 27 404 2.08 27 608 2.43 48 608 2.43 48 322 1.76 18 322 1.76 18
Total oxide & primary open pit   12,923 1.66 690 12,938 1.69 701 19,492 1.72 1,075 18,635 1.62 970 32,415 1.69 1,765 31,573 1.65 1,671 6,077 1.53 299 3,859 1.32 164
Open pit stockpile 0.5 2,581 0.73 61 1,985 0.66 42 0 0 0 0 0 0 2,581 0.73 61 1,985 0.66 42 0 0 0 0 0 0
Spent ore stockpile 0.5 1,721 0.65 36 1,311 0.61 26 0 0 0 0 0 0 1,721 0.65 36 1,311 0.61 26 0 0 0 0 0 0
Rom expansion stockpile 0.5 0 0 0 345 0.8 9 0 0 0 0 0 0 0 0 0 345 0.8 9 0 0 0 0 0 0
Marginal ore stockpiles 0.3 1,517 0.43 21 1,586 0.44 22 0 0 0 0 0 0 1,517 0.43 21 1,586 0.44 22 0 0 0 0 0 0
Total stockpiles   5,819 0.63 118 5,228 0.59 99 0 0 0 0 0 0 5,819 0.63 118 5,228 0.59 99 0 0 0 0 0 0
Total Tucano Open Pit & stockpiles   18,742 1.34 807 18,166 1.37 800 19,492 1.72 1,075 18,635 1.62 970 38,235 1.53 1,883 36,801 1.5 1,770 6,077 1.53 299 3,859 1.32 164
Tap AB Underground primary* 1.2 0 0 0 22 1.49 1 0 0 0 1,025 2.3 76 0 0 0 1,047 2.28 77 4,216 2.85 386 3,653 3.19 375
Urucum Underground primary (Cut-off >1.6 g/t Au) 1.6 260 4.06 34 260 4.06 34 2,634 4.24 359 2,634 4.24 359 2,894 4.22 393 2,894 4.22 393 5,106 2.71 445 5,106 2.71 445
Urucum Underground primary (Cut-off 1.2 g/t -1.6 g/t Au) 1.2 to 1.6 3 1.4 0 0 0 0 26 1.44 1 0 0 0 29 1.43 1 0 0 0 3,704 1.38 165 3,733 1.38 166
Total Tucano Underground   263 4.03 34 282 3.86 35 2,660 4.21 360 3,659 3.7 435 2,923 4.2 394 3,941 3.71 470 13,026 2.38 996 12,492 2.45 986
Grand total Tucano   19,005 1.38 841 18,448 1.41 835 22,152 2.02 1,436 22,293 1.96 1,405 41,157 1.72 2,277 40,742 1.71 2,240 19,102 2.11 1,295 16,351 2.19 1,150
                                                       

Please see footnotes under Table 14.47 for the 30 June 2017 report.

Footnotes for the 31 Dec 2016 Mineral Resource estimate follow:

* The Dec 2016 Tap AB UG Resource includes 169 kt at 4.51 g/t Au for 25 koz Au of Inferred Oxide in the Inferred primary Category.

* The Dec 2016 Tap AB UG Resource was all classed as Inferred by BDR. The June 2017 Tap AB UG Resource used the geostatistical resource classification of the original estimated model.

Source: BDR.

 

 

amcconsultants.com

141

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

15Mineral Reserve estimates
15.1Summary

The Mineral Reserve estimates for the Tucano operation were reported in accordance with the guidelines of NI43-101 and the Canadian Institute of Mine Metallurgy and Petroleum Definition Standards for Mineral Resources and Mineral Reserves 2014 (CIM Standards).

“A Mineral Reserve is the economically mineable part of a Measured and/or Indicated Mineral Resource. It includes diluting materials and allowances for losses, which may occur when the material is mined or extracted and is defined by studies at Preliminary Feasibility or Feasibility level as appropriate that includes application of Modifying Factors. Such studies demonstrate that, at the time of reporting, extraction could be reasonably justified.”

Open Pit Mineral Reserves were estimated through an open pit optimization exercise using the Measured and Indicated Resources in the block models provided by B Wolfe for the Tap AB and Urucum deposits and Measured and Indicated Resources in the block models provided by Marcello Batelochi and Paul Tan for the Urucum East and Tap C deposits.

Mineral Reserves were reported within detailed engineered pit designs and the LOM plans based on these pit shells.

The Mineral Reserves inside the engineered pit designs for the Tap AB open pits were estimated using COGs estimated for each deposit and ore type based on the following gold prices; Open Pit Optimization Shell used for Pit Design:US$1,150/oz and a US$:R$ exchange rate of 1:3.2. Reserves reported within the Pit Design: US$1,200/oz and a US$:R$ exchange rate of 1:3.25.

The Mineral Reserves inside the engineered pit designs for the remaining open pits were estimated using COGs estimated for each deposit and ore type based on the following gold prices; Open Pit Optimization Shell used for Pit Design: US$1,100/oz and a US$:R$ exchange rate of 1:3.4. Reserves reported within the Pit Design: US$1,200/oz and a US$:R$ exchange rate of 1:3.25.

The Mineral Reserves are contained within four open pit deposits, one underground zone, and surface stockpiles. Proved and Probable Mineral Reserves for the mine as of 30 June 2017 are estimated to be 24.5 Mt at 1.79 g/t Au containing approximately 1.41 Moz of gold. The Mineral Reserve estimate for Tucano as of 30 June 2017 is summarized in Table 15.6.

Open Pit Mineral Reserves represent approximately 74% of the total tonnes and 71% of the total ounces of contained gold. Current open pit mine life is seven years (2018 to 2024). Underground Mineral Reserves represent approximately 12% of the total tonnes and 23% of the total ounces of contained gold. Current underground mine life is projected to be seven years (2018 to 2024).

Minesure is of the opinion that the 30 June 2017 Mineral Reserves relating to the open pits have been estimated in a manner consistent with industry practices and NI 43-101 guidelines.

AMC is of the opinion that the 30 June 2017 Mineral Reserves relating to the underground have been estimated in a manner consistent with industry practices and NI 43-101 guidelines.

There are two principal locations of the Tucano Deposit namely, Tap AB and Urucum. There are two smaller locations being Urucum East and Tap C. Tap AB is located 1.2 km east of the processing plant and infrastructure and comprises three conjoined deposits being AB1, AB2, and AB3. Urucum centroid is located 5 km north-north east of the processing plant and comprises four conjoined deposits, Urucum South, Urucum Central South, Urucum Central North, and Urucum North. Urucum East is located 1.4 km north east of Urucum North pit. Tap C is located 2.8 km north-north east of the processing plant.

The locations of the deposits are shown in Figure 15.1. 

amcconsultants.com

142

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Figure 15.1 Deposit location plan

Source: N. Spicer (Minesure Pty Ltd).

amcconsultants.com

143

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Open cut mining has previously been undertaken on all deposits except Urucum East.

Mineral Reserves for the Underground were estimated by AMC in a pre-feasibility study completed in 2016. The study estimated the cash flow of establishing and operating an underground operation at Urucum North using mechanized long-hole stoping techniques. The recovery of Mineral Reserves would sustain the underground mining for up to eight years and realize 2.4 Mt of ore grading 3.6 g/t Au and containing 278,000 oz of gold.

To date there has been no underground mining production.

The proportion of Reserves by deposit is shown in Table 15.1.

Table 15.1 Proportion of reserves by deposit

Deposit % of total
Tonnes Au (oz)
Tap AB 26% 29%
Urucum 42% 39%
Tap C 5% 3%
Urucum East 1% 1%
Urucum Underground 12% 23%
Stockpiles 14% 5%

Test work and processing results indicate that the Mineral Reserves are all amenable to processing using Carbon in Leach (CIL) technology.

15.2Open pit
15.2.1Reserve block model

The mining engineering work related to the pit optimizations and engineered pit designs was carried out using the block models prepared by B Wolfe in January 2017 for the Urucum deposit and in June 2017 for the Tap AB deposit. The block models prepared by Marcello Batelochi and Paul Tan in February 2017 were used for the Tap C and Urucum East deposits. A parent block size of 9 m x 20 m x 8 m (Y, X, Z) metres was used for the Tap AB and Urucum deposits, and 20 m x 8 m x 4 m (Y, X, Z) metres was used for the Tap C deposit, and 10 x 5 x 2 (Y, X, Z) metres was used for the Urucum East deposit. The models contain blocks coded with the following information:

Gold grade
Block proportion of ore
Resource category (Measured, Indicated, and Inferred)
Density
Oxidation factor
Lithology and domain
Material volumes.

Life of mine (LOM) final designs have been compiled for the open pits and these were the basis of estimating the Mineral Reserves for the Tucano project. Intermediate or annual pit designs have not been compiled.

amcconsultants.com

144

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

15.2.2Open pit optimization

The open pit optimizations were carried out for all deposits using the Lerchs-Grossman 3D algorithm in the Whittle 4D Software. Using mining costs, processing costs, gold recovery values and an overall pit slope, the pit optimizer determines an ultimate pit shell that delineates the volume of extraction that maximizes value.

A series of pit optimizations were produced using a range of gold selling prices in order to produce an industry standard pit-by-pit graph. This process is used to evaluate the sensitivity of the pit optimizations to changes in mineral selling prices, as well as to evaluate the effect of the pit size and stripping ratios on the project Net Present Value (NPV). The optimization process produces a series of nested pit shells that prioritize the mining of the most economic material. Less profitable material (lower grade and / or high strip ratio) is by definition only mined in later pit shells as the input mineral selling price is increased.

From these results, appropriate pit shells for the deposits were selected as a basis for the engineered pit designs and Mineral Reserve estimates. All pit optimizations were run using reasonable and relevant economic, cost, recovery, and pit slope assumptions, and were run on diluted gold grades. In accordance with the guidelines of NI 43-101 and CIM Standards, only resource blocks classified as either Measured or Indicated were allowed to drive the pit optimizer for Mineral Reserve reporting purposes.

15.2.3Dilution and extraction

Resources for Tap AB and Urucum were estimated using MIK which include a proportion of dilution when estimating the resource block grades. MIK estimation techniques have only been in use at Tucano for a limited amount of time so no real trends can be discerned from the reconciliation data. Based on the limited reconciliation data available it was decided to increase the proportion of included dilution. Accordingly, Resources were diluted by an additional 15% in the oxide and 20% in the fresh.

Mining recovery (extraction) varied by deposit and ore type. It was found that the quantity of ore mined from Urucum was consistent with model predictions for both oxide and fresh ores. Reconciliation data indicated that the quantity of ore mined from Tap AB was generally lower than that indicated by the model for both oxide and fresh ores.

No mining has yet taken place at Urucum East so it was not possible to derive dilution and recovery factors from reconciliation data. The factors used for this deposit were derived from using the Tap AB oxide ore factors and Urucum fresh ore factors.

15.2.4Gold grade data

The gold grade data (undiluted) was provided in the mineral resource block model and is the main item used for pit optimization and Mineral Reserve estimates. The grades were modified to account for mining dilution and the block volumes were modified to allow for dilution and mining recovery.

15.2.5Cost parameters for pit optimization

The key pit optimization parameters used to derive the economic pit shells for the deposits are summarized in Table 15.2. The optimizations were based on parameters and cost data projected for the 2017 Budget.

amcconsultants.com

145

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 15.2 Optimization cost parameters

Item Unit Tap AB Urucum
Oxide Fresh Oxide Fresh
Value Value Value Value
Gold price $/oz 1,150 1,150 1,100 1,100
  $/gm 36.97 36.97 35.37 35.37
Optimization selling price $/gm 36.23 36.23 34.66 34.66
Metallurgical recovery for Au % 93 93 95 93
Gold value $/gm 34.39 34.39 33.60 32.89
State royalty % 2.0 2.0 2.0 2.0
Realized value $/gm 33.70 33.70 32.93 32.23
Treatment cost $/t ore 10.33 13.96 9.62 13.74
Crusher feed $/t ore 0.38 0.38 0.36 0.36
Admin cost $/t ore 2.08 2.08 1.88 1.88
Corp overheads $/t ore 0.00 0.00 0.00 0.00
Technical services $/t ore 0.80 0.80 0.74 0.74
Dewatering $/t ore 0.98 0.98 0.56 0.56
Grade control $/t ore 1.12 1.12 1.24 1.24
Mining contractor fixed $/t ore 3.58 3.58 4.38 4.38
Ore haulage $/t ore 0.00 0.00 2.34 2.34
Total processing cost $/t ore 19.27 22.90 21.11 25.23
Mining dilution % 15 20 15 20
Mining recovery % 90 90 100 100

Mining costs were based on the Mining Contract rates escalated in accordance with the Rise and Fall clause of the mining contract.

15.2.6Pit optimization mill recovery

Test work and operations has indicated that a consistent metallurgical recovery of 93% is projected for the oxide and fresh ore for Tap AB. Metallurgical recovery for Urucum is estimated to be 95% for the oxide and 93% for the fresh ore following the planned plant upgrade.

15.2.7Tap AB optimization results

A series of pit shells for Tap AB were run using gold selling prices ranging from US$550/oz to US$1,650/oz at US$ / R$ exchange rate of 1:3.2 and using the other parameters listed in the sections above. The results of the pit optimization are presented in Figure 15.2.

amcconsultants.com

146

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 15.2 Tap AB optimization results

Source: N. Spicer (Minesure Pty Ltd).

Shell 21 at the gold price of US$1,150/oz generated the maximum average discounted cash flow and was chosen as the basis for the Tap AB final design.

15.2.8Urucum optimization results

A series of pit shells for Urucum were run using gold selling prices ranging from US$550/oz to US$1,650/oz at US$:R$ exchange rate of 1:3.4 and using the other parameters listed in the sections above. The results of the pit optimization are presented in Figure 15.3.

amcconsultants.com

147

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 15.3 Urucum optimization results

Source: N. Spicer (Minesure Pty Ltd).

Shell 21 at the gold price of US$1,100/oz generated the maximum average discounted cash flow and was chosen as the basis for the Urucum final design.

15.2.9Open pit COG - Pit optimization and Reserves

COGs used in the open pit optimization were estimated for each deposit based on the following criteria:

The gold price - US$1,150/oz (Tap AB) and US$1,100 (Tap C and Urucum).
The applicable mine royalty payments.
Metallurgical Recoveries.
Specific ore mining and hauling costs.
The process operating costs and on-site (and off-site) metal recoveries by material type, applicable or selected process method, and orebody.

Gold price assumptions are dictated by the corporate office. Royalties are a percentage due to the local and federal governing bodies.

A set of process and overhead costs for processing oxide and fresh ore were estimated by the process manager based on current operating costs and projected operating costs. Costs used to estimate COGs do not include mining costs, unless there is a marginal cost for ore compared to waste in a given pit. COGs consider the general and administration (G&A) costs as part of the process cost. Estimation of COGs for the various pits is shown in Table 15.3.

amcconsultants.com

148

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 15.3 COG estimation parameters using pit shell optimization gold price

Deposit Ore type Processing cost ($/t) G&A cost ($/t) Tech services $/t Haulage ($/t) Royalty (%) Met Rec (%) Dilution (%) Mining Rec (%) COG Au (g/t)
Tap AB Oxide 10.71 2.08 0.80 0 2.0 93 15 90% 0.66
Fresh 14.34 2.08 0.80 0 2.0 93 20 90 0.82
Urucum Oxide 9.98 1.88 0.74 2.34 2.0 95 15 100 0.74
Fresh 14.10 1.88 0.74 2.34 2.0 93 20 100 0.94
Tap C Oxide 9.98 1.88 0.74 2.34 2.0 95 15 90 0.66
Fresh 14.10 1.88 0.74 2.34 2.0 93 20 90 0.86
Urucum East Oxide 9.98 1.88 0.74 2.34 2.0 95 15 90 0.74
Fresh 14.10 1.88 0.74 2.34 2.0 93 20 100 0.94

G&A = General and Administration, Tech = Technical, Met Rec = Metallurgical recovery, Mining Rec = Mining recovery

In November 2017, the gold price for the reporting of Mineral Reserves was increased to US$1,200/oz and the COG for each pit was recalculated based on this price, the optimization process costs and the revised haulage costs. A metallurgical recovery of 93% was applied for both oxide and sulphide. These COGs were used to define the Mineral Reserve COGs for reporting within the reserve pits designed with the lower gold price optimized shells (Table 15.2). Table 15.4 below shows the COG estimation parameters using a gold price of US$1,200/oz.

 

amcconsultants.com

149

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 15.4 COG estimation parameters using the US$1,200 gold price

Deposit Ore type Processing cost ($/t) G&A cost ($/t) Tech services ($/t) Haulage ($/t) Royalty (%) Met Rec (%) Dilution (%) Mining Rec (%) Calculated COG Au (g/t) COG Au Reserve (g/t)
Tap AB Oxide 10.57 2.05 0.79 0.00 2 93 15 90 0.62 0.6
Fresh 14.11 2.05 0.79 0.00 2 93 20 90 0.77 0.7
Urucum Oxide 10.57 2.05 0.79 2.45 2 93 15 100 0.70 0.7
Fresh 14.11 2.05 0.79 2.45 2 93 20 100 0.85 0.8
Tap C Oxide 10.57 2.05 0.79 1.40 2 93 15 90 0.67 0.6
Fresh 14.11 2.05 0.79 1.40 2 93 20 90 0.82 0.8
Urucum East Oxide 10.57 2.05 0.79 2.69 2 93 15 90 0.69 0.7
Fresh 14.11 2.05 0.79 2.69 2 93 20 90 0.86 0.7

G&A = General and Administration, Tech = Technical, Met Rec = Metallurgical recovery, Mining Rec = Mining recovery

 

amcconsultants.com

150

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

15.3Underground mining
15.3.1Underground mine Mineral Reserve estimate

The underground Mineral Reserves were developed from the Mineral Resource block model (reference: urucum_ug_resource2015_v17.mdl) which was provided to AMC by BDR.

The estimation of Mineral Resources that form the basis of the Mineral Reserve estimates is described in Section 14 of this report. Mr Gary Methven, P.Eng., takes responsibility for the estimation of Urucum North Underground Mineral Reserves.

Underground Mineral Reserves have been estimated based on:

COG criteria indicated in Section 15.3.
Dilution and mining recovery estimates as discussed in Section 15.4 and Section 15.5.
In accordance with NI 43-101 standards, no Inferred material has been included in this Mineral Reserve estimate.

The estimated Mineral Reserve is based only on Measured and Indicated Mineral Resource and is effective as of 30 June 2017 and is provided in Table 15.5. AMC notes that although there is approximately 10% of the Mineral Resource estimated as a Measured resource, given the accuracy of the PFS it is reasonable to convert Measured Resources to Probable Reserves due to uncertainties with the modifying factors.

Table 15.5 Urucum North Underground Mineral Reserve estimate

Category Ore tonnes (x 1,000) Grade of contained metal Au (g/t)
Proven    
Probable 2,378 3.64
Total 2,378 3.64

Notes:

2018 Mineral Reserves are as of 30 June 2017 and based on a COG of 1.6 g/t Au. The COG is based on an incremental mining and processing cost of US$50/t, metallurgical recovery of 90%, a gold price of US$1,120/oz and an exchange rate of US$:R$ of 1:3.8.
A 0.5 m dilution skin was assumed for the HW and FW side of the production stopes making the total dilution 1.0 m in width. Ore losses were assumed to be 8% for the Benching method, 14% for the Up-Hole retreat method, and ore losses for the recovery of the sill pillars were assumed to be 35%.
15.3.2Orebody geometry

The Urucum North Underground mineralization covers a strike length of approximately 800 m down to a depth of approximately 500 m below the current open pit design (BDR pit design of 11 March 2016). Mineralization is hosted within the banded iron formation (BIF) unit which is approximately 100 m wide.

Continuous high grade, shallow plunging ore lodes exist along the mineralized BIF. BDR have modelled 3 main ore lodes, namely, Lode 1, Lode 2, and Lode 300, each lode dipping sub-vertically and generally separated by 20 m to 30 m.

Since the earliest days of exploration and mining at Tucano, it has been recognized that a number of ore shoots exist within the mineralized lodes. These shoots plunge in two main orientations, namely:

Shallow dipping ore shoots plunging 15˚ to 25˚ towards the north.
Steeply dipping ore shoots plunging 50˚ to 60˚ towards the north.

amcconsultants.com

151

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Ore shoots are defined as contiguous regions where drill intersections meet specific grade and metal content criteria.

15.3.3Cut-off grade (COG)

An incremental COG of 1.6 g/t Au has been chosen as the basis for estimating Mineral Reserves. The basis for this COG is:

Optimization studies undertaken as part of August 2014 Scoping study based on evaluation of COGs from 1.0 g/t Au through to 3.0 g/t Au, in 0.5 g/t Au increments.
An incremental mining and processing cost of US$50/t.
Metallurgical recovery of gold of 90%.
A gold price of US$1,120/oz equating to US$36/g.

The incremental costs do not include any development costs or contractor equipment leasing costs. AMC has undertaken sufficient design, scheduling and costing work to test the effect of increasing the COG above 1.6 g/t Au. This work indicates that the low-grade stopes (between 1.6 g/t Au and 2.0 g/t Au added value to the overall project economics, partially because of already expensed “fixed costs” and already costed development that is required to access higher grade stopes.

15.3.4Dilution and mining recovery estimates

There are two main sources of dilution in narrow vein stopes:

1Planned dilution: this is the dilution required to achieve the designed stope shape. Designed dilution can result from waste included:
To achieve minimum mining width.
To achieve a viable mining shape.
2Unplanned dilution: this is dilution that is outside of the designed stope shape. Depending on the mining method, it may include both overbreak and floor dilution.

Overbreak is typically a result of blasting practices and geotechnical conditions. Floor dilution is the result of mucking waste rock from the rock fill floor.

AMC has applied a planned dilution of 0.50 m to each of the hangingwall and the footwall with a minimum stope width of 2 m. The stope shape is then evaluated against the Mineral Resource model. After the Mineable Shape Optimizer (MSO) wireframes were generated, the following ore losses have been applied to the stope tonnes:

Up-hole Retreat mining areas (mining in a down-dip direction)
6 m rib pillar every 50 m equivalent to 12% ore loss.
2% ore loss for difficulty to muck ore at the bottom of stopes.
Total ore loss = 14%.
Bench stoping areas (mining in an up-dip direction)
3 m rib pillar every 50 m equivalent to 6% ore loss.
2% ore loss for difficulty to muck ore at the bottom of stopes.
Total ore loss = 8%.
Sill pillar recovery
Ore loss = 35% due to mining below unconsolidated rockfill.
Ore development recovery
Recovery of development ore has been assumed to be 100% (Note: development dilution is captured in the development wireframes when assessed by Mine24D software).

 

amcconsultants.com

152

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

15.3.5Mining method criteria and modifying factors

Up-hole Retreat mining parameters include:

20 m level interval (15 m - 20 m production holes).
Minimum mining width of 2.0 m (plus dilution).
6 m rib pillars every 50 m along strike.
Generally, 3 x 20 m lifts between sill pillars, equating to an ore block height of 60 m.
Mining proceeding in a top down sequence.
Ore dilution based on 0.5 m of FW and 0.5 m of HW dilution.
Mining recovery of 86% assumed.

Down-Hole Benching mining parameters include:

20 m level interval (15 m - 20 m production holes).
Minimum mining width of 2.0 m (plus dilution).
3 m rib pillar every 50 m along strike.
Generally, 3 x 20 m lifts between sill pillars, equating to an ore block height of 60 m.
Mining proceeding in a bottom up sequence.
Ore dilution based on 0.5 m of FW and 0.5 m of HW dilution.
Mining recovery of 92% assumed.

Sill Pillar mining parameters include:

20 m level interval (15 m - 20 m production holes).
Minimum mining width of 2.0 m (plus dilution).
Continuous along strike.
Recovered using up-holes drilled from below the sill.
Dilution based on 0.5 m of FW and 0.5 m of HW dilution.
Mining recovery of 65% assumed.
15.4Combined Mineral Reserve estimate

Open Pit Proved and Probable Mineral Reserves were estimated using the engineered pit designs, the Mineral Resource block models, and modifying factors. The Urucum underground Mineral Reserve was restated by AMC based on the PFS study completed in 2016 and in line with NI 43-101 guidelines with an effective date of 30 June 2017. The Mineral Reserves have been estimated in accordance with Canadian NI 43-101 Standards of Disclosure for Mineral Projects of August 2011 and Definition Standards for Mineral Resources and Mineral Reserves adopted by the CIM Council on May 2014. The estimated Mineral Reserves for the Tucano project as of 30 June 2017 are shown in Table 15.6.

Exchange rates of US$ to the Brazilian Real (R$) used for the estimation of Mineral Reserves are discussed below Table 1.3.

amcconsultants.com

153

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 15.6 Total Mineral Reserves - 30 June 2017

Brazil Cut-off Proved Reserve Probable Reserve Total Mineral Reserve
Au (g/t) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000) Tonnes (‘000) Grade Au (g/t) Ounces (‘000)
Urucum Open Pit oxide 0.7 374 1.21 15 180 1.18 7 554 1.20 21
Urucum East Open Pit oxide 0.7 0 0.00 0 151 1.71 8 151 1.71 8
Tap AB Open Pit oxide 0.6 2,384 2.16 166 2,024 1.76 115 4,408 1.98 280
Tap C Open Pit oxide 0.6 362 1.08 13 191 0.99 6 553 1.05 19
Total oxide open pit   3,120 1.92 193 2,545 1.66 136 5,666 1.80 329
Urucum Open Pit primary 0.8 4,446 1.69 241 5,246 1.81 306 9,692 1.76 547
Urucum East Open Pit primary 0.7 0 0.00 0 16 1.50 1 16 1.50 1
Tap AB Open Pit primary 0.8 1,274 2.00 82 1,188 1.72 66 2,462 1.86 147
Tap C Open Pit primary 0.8 229 1.31 10 387 1.44 18 615 1.39 28
Total primary open pit   5,949 1.74 333 6,836 1.77 390 12,785 1.76 723
Urucum Open Pit total   4,820 1.65 256 5,425 1.79 312 10,245 1.72 568
Urucum East Open Pit total   0 0 0 167 1.69 9 167 1.69 9
Tap AB Open Pit total   3,658 2.10 247 3,212 1.75 181 6,870 1.94 428
Tap C Open Pit total   591 1.17 22 577 1.29 24 1,168 1.23 46
Total oxide and primary open pit   9,069 1.80 525 9,381 1.74 526 18,450 1.77 1,051
Open pit stockpile 0.5 1,985 0.66 42 0 0.00 0 1,985 0.66 42
Spent ore stockpile 0.5 1,311 0.61 26 0 0.00 0 1,311 0.61 26
ROM expansion stockpile 0.5 345 0.80 9 0 0.00 0 345 0.80 9
Total stockpiles 0.5 3,642 0.66 77 0 0.00 0 3,642 0.66 77
Total Tucano Open Pit & stockpiles   12,711 1.47 603 9,381 1.74 526 22,092 1.59 1,128
Urucum Underground primary   0 0.00 0 2,378 3.64 278 2,378 3.64 278
Total Underground primary   0 0.00 0 2,378 3.64 278 2,378 3.64 278
Grand total Tucano   12,711 1.47 603 11,759 2.12 804 24,470 1.79 1,406

Notes:

2018 Open Pit Mineral Reserves are stated as of 30 June 2017 based on the COGs as detailed in Table 1.3 above. Reserves are reported within open pit designs based on pit optimized shells using the following optimization COGs; Tap AB Oxide: 0.66g/t Au, Tap AB Fresh: 0.82 g/t Au, Urucum Oxide 0.74 g/t Au, Urucum Fresh 0.94 g/t Au, Tap C Oxide 0.66 g/t Au, Tap C primary 0.86 g/t Au, Urucum East Oxide 0.74 g/t Au, Urucum East Fresh 0.94 g/t Au. The COG is based on total costs per pit (inclusive of processing, G&A, tech services and haulage, exclusive of mining costs) and averages US$12.8 for oxide and US$16.8 for primary. Metallurgical recoveries are 95% for oxide and 93% for sulphides. The gold price used for the open pit optimizations was $1,150/oz for Tap AB and $1,100 for Tap C and Urucum. The gold price used to calculate the COGs for the reserves reported within the optimized pit designs was US$1,200 per ounce. An exchange rate of US$:R$ of 1:3.2 for Tap AB and 1:3.4 for Urucum was used. Open Pit Mining Recoveries of 100% for oxide and primary were used at Urucum, 90% for oxide and primary at Tap C and Tap AB and 90% oxide, 100% primary at Urucum East. Dilution used for all pits was 15% for oxide and 20% for primary.

amcconsultants.com

154

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

2018 Underground Mineral Reserves are stated as of 30 June 2017 and based on a COG of 1.6 g/t Au. The COG is based on an incremental mining and processing cost of US$50/t, metallurgical recovery of 90%, a gold price of US$1,120/oz and an exchange rate of US$:R$ of 1:3.8.
A 0.5 m dilution skin was assumed for the HW and FW side of the underground production stopes making the total dilution 1.0 m in width. Ore losses were assumed to be 8% for the Benching method, 14% for the Up-Hole retreat method, and ore losses for the recovery of the sill pillars were assumed to be 35%.
The JORC reserve released on 19 December 2017 to the ASX ("Interim Mineral Resource and Ore Reserve Update as at 30 June 2017") stated the total Urucum Underground Reserve was 2,972 kt at 3.61 g/t Au for 345 koz Au. This reserve was reported by AMC inclusive of Inferred resource blocks captured inside the stope designs that were optimized on Measured and Indicated Resources in the 2016 PFS. The Inferred Resources falling within the stope designs was removed from the calculations and reporting of the NI 43-101 compliant Urucum Underground Reserves by AMC Vancouver in 2018 and has been quoted in the Table 1.3 above.

 

 

 

 

 

 

 

amcconsultants.com

155

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

15.5Factors that may impact Mineral Reserve estimates

The main factors that may impact the mineral reserve estimates are as follows:

Metal prices and exchange rate assumptions.
Mining, process, and operating cost or recovery assumptions.
Ability to obtain permits in a timely manner.
Social license to operate being maintained.

The QP is not aware of any other modifying factors that could materially impact the mineral reserves of the Tucano operation.

 

 

amcconsultants.com

156

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16Mining methods
16.1Open pit mining

Open pit mining is currently being undertaken by new mine contractor Unienge & Modulo (U&M), the largest mining and locally experienced contractor in Brazil. The mining operations are based on the use of hydraulic excavators and a haul truck fleet engaged in conventional open pit mining techniques. Details of the pit slope design parameters based on independent review work is provided in Section 16.2.1.

Excavated material is loaded to trucks and hauled to either the ROM, long term low grade or marginal stockpiles, the iron ore stockpile, or the waste dump. Ore excavation and haulage is monitored by quality control personnel employed by the Geology department and details of material movement are recorded by a radio dispatch system “Tecmine”. Oxide material is free dig with transitional material lightly blasted to loosen it for digging. Fresh rock is typically blasted on 4 m benches however 8 m benches are also fired. For wide sulphide ore lodes, the ore can sometimes be blasted separately if the shot is sufficiently large to minimize dilution. Normally ore and waste are fired together requiring the use of 8 m long poly pipes or Blast Vector Indicators (BVI) at each node of the ore polygon to determine post-blast movement. Ore sent to the ROM is stockpiled on fingers of oxide or sulphide within various grade cut-off categories to facilitate blending to achieve the desired oxide / sulphide proportions and grade.

16.2Geotechnical assumptions
16.2.1Overall pit slopes

SRK and Peter O’Bryan and Associates made recommendations regarding the wall design parameters for the Tucano Project Pits. These are shown in Table 16.1.

Table 16.1 Recommended wall design parameters

Pit Domain (above interface) Bench height (m) Berm width (m) Batter face angle Bench stack height (m) Inter-ramp angle Geotechnical Berm width (m)
Tap C Friable (W3) 4 3 70° 80 41.9° 10
Unweathered 20 8 75° 120 56.3° n/a
Tap AB Friable (R2) 4 3 70° 60 41.9° 40
Unweathered 20 8 75° 120 56.3° n/a
Urucum Friable (R2) 4 3 70° 60 41.9° 40
Unweathered 20 8 75° 120 56.3° 20

Additionally, Geotechnical Consultant Luis Navarro has recommended (Site Visit Report October 2015) that walls in weathered pegmatite have batter angles reduced to 60°. This particularly applies to Urucum Central South pit and potentially Urucum Central North Pit which has massive pegmatite running parallel to the strike of the orebody in the final west wall position.

The current Urucum Central South pit is designed to 158 m below the surface and should require a 20 m wide geotechnical berm at approximately 150 m below surface however the benches at the bottom 20 m of the pit are essentially narrow and short, so a geotechnical berm is not required. Following a review of the AB pits in March 2017 Peter O'Bryan advised that the following regimes for geotechnical berms could be adopted:

Slopes up to 120 m (= two 60 m stacks): One geotechnical berm at 20 m width.
Slopes up to 180 m (= three 60 m stacks): Two geotechnical berms at 30 m width.
Slopes 240 m (three or more 60 m stacks): Three geotechnical berms at 40 m width.

 

amcconsultants.com

157

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The heights are measured above the oxide / fresh interface.

Overall slope angles for the existing pits were measured from the 2016 final designs and these are shown in Table 16.2. The angles included berms and access roads where intersected.

Table 16.2 Measured overall slope angles (degrees)

Pit Total depth (m) Quadrant
North East South West
URN 160 28 47 35 45
URCN 150 21 49 20 49
URCS 150 33 48 44 49
URS 115 45 52 48 55
UR_East 96 30 38 28 17
AB3 160 45 37 41 46
AB1/2 270 22 26 27 38

URN = Urucum north, URCN = Urucum Central North, URCS = Urucum Central South, UR_East = Urucum East.

The majority of the measured slope angles are lower than the recommended FS Inter ramp slope (IRS) angles. This indicates that access requirements are greater than estimated in the FS.

For most of the deposits the North and South slope angles are dictated by the access ramp and in practice tend to be lower than the recommended slope angles. For the optimization the recommended IRS angles were used for North and South walls of all pits.

Different slope characteristics were estimated for oxide and fresh rocks because of the difference in competence. Fresh rocks are by nature stronger and able to remain stable at steeper slope angles whereas the oxidized rocks tend to crumble and fail at too steep an angle.

16.2.1.1Urucum

At Urucum the east and west walls are of similar heights. The depth of weathering is between 20 m and 30 m below surface. The fresh rock is very competent except where there are extensive pegmatite intrusions. Pegmatite affects all of the Urucum pit walls. It was proposed that the oxide zone in the Urucum Pits use IRS angles of 40°. The exception is Urucum South which is basically a circular pit with a spiralling ramp. The current design has a 14 m wide ramp which is only suitable for two-way operation for Volvo trucks. It was proposed to use 42° on all oxide walls.

IRS angles for the fresh zones were measured from the 2016 designs and are listed in Table 16.3.

16.2.1.2Urucum East

Urucum East is a small stand-alone deposit located 700 m east of the Urucum north zone. The deposit is wholly oxide. Due to the small size of the deposit the overall slopes are flattened by the access road and also by the shallow footwall on the north and west side. An existing design has overall slope angles of 30° in the north quadrant which has a 96 m high wall incorporating a 40 m wide geotechnical berm at the 253 mRL. Slope angles for the remaining quadrants are shown in Table 16.3.

16.2.1.3Tap AB

Tap AB3 has been mined down to the 81 mRL. The east wall and west walls are mostly fresh from the 129 mRL down however the middle of the zone is oxidized down to the 17 mRL. The north wall is all oxide and the south wall has fresh rock occurring at the 140 mRL. The south wall has an overall slope angle of 41° in the oxide and 40° in the fresh. The north wall final design has an overall slope angle of 45° which includes an eight metres wide berm on the 117 mRL and a narrow access ramp. The east wall has a 40 m wide geotechnical berm at the 117 mRL and a 20 m wide access ramp which flattens to wall to 37°. It is proposed that the IRS in oxide be 33° in the North, 31° in the East, 30° in the South quadrant and 38° in the West quadrant. The overall slope angle for the fresh rock is estimated to be 47° in the East and South quadrants and 56° for the remainder.

amcconsultants.com

158

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Tap AB1 and Tap AB2 join up as one pit in the current final design. The eastern wall is oxide down to the 33 mRL. The measured overall slope angle is 26°. The eastern wall design had four stack berms of 40 m width at 60 m vertical intervals, hence the low overall slope angle. The 2016 design was based on an outdated topography which has subsequently been re-compiled. The new topography showed that one of the stack berms in the east wall could be eliminated leading to a steeper overall slope angle of 33° in the oxide rock. The west wall is much shallower and does not require stack berms consequently the overall slope angle in oxide is 38°.

It is proposed to use 33° slope angle in oxide rock for the north, 30° for the east, 31° for the south walls, and 38° in the west wall. The overall slope angle for the fresh rock is estimated to be 56° in the north, 47° in the east, 47° in the south, and 56°for the west wall.

16.2.1.4Pegmatite

The recommended design parameters in oxidized pegmatite are:

Batter height 4 m
Batter angle 60°
Berm width 3 m

The average slope angle becomes 35° and this will be used throughout. Where possible ramps will not be mined in the oxidized pegmatite because of its inherent instability.

The current south-east wall of Tap AB1 has a highly oxidized pegmatite abutting carbonate and iron stone lithologies which are very friable. This material is unstable and readily slumps. It is particularly important that this area be mined at a shallow angle.

16.2.1.5Proposed overall slope angles

The proposed overall slope angles are summarized in Table 16.3.

amcconsultants.com

159

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Table 16.3 Proposed overall slope angles (degrees)

Pit Total depth (m) Rock type Quadrant
North East South West
URN 160 Oxide 40 40 40 40
Fresh 45 45 45 51
URCN 150 Oxide 40 40 40 40
Fresh 55 55 55 55
URCS 150 Oxide 40 40 40 40
Fresh 50 49 50 52
URS 115 Oxide 42 42 42 42
Fresh 50 51 50 49
UR_East 96 Oxide 30 38 30 30
AB1/2/3 270 Oxide 33 30 31 38
Fresh 56 47 47 56

URN = Urucum north, URCN = Urucum Central North, URCS = Urucum Central South, UR_East = Urucum East.

16.2.2Engineered pit designs

The engineered pit designs were completed using the pit optimization shells as a guide in order to maximize the value and gold recovered inside the ultimate pits. The resulting pit designs include practical geometry that is required in an operational mine, such as the haul road to access all the benches, recommended pit slopes with geotechnical berms, proper benching configuration, and smoothed pit walls.

The resulting engineered pit designs were used to estimate the Mineral Reserves in this report.

16.2.2.1Tap AB

At the end of June 2017 mining was active only in Tap AB1 and Tap AB2. Tap AB pits will be the main source of plant feed for up to 18 months because the processing plant in its current configuration can only process a proportion of the Urucum ore which is mainly primary or fresh. Modifications to the processing plant are scheduled to be completed by November 2018 to enable the primary ores to be treated effectively.

Due to overlapping, AB1 and AB2 pit designs have been combined into a single pit. The long axis length of the AB deposit is approximately 1,700 m, and the minor axis width ranges from 400 m in the AB3 pit to 950 m in the AB1/2 pit. The designed pit bottom elevation of AB1/2 is -47 mRL and the designed pit bottom for AB3 is 5 mRL.

The primary pit exit for AB1/2 is at 115 mRL and for AB3 at 160 mRL.

Access ramps are designed at eight (8) metre width for the bottom 20 m vertical, then 14 m width for the next 60 m Vertical and then 23 m width for the remainder. Ramp gradients for the 8 m wide and 14 m wide sections will be 12.5% (1 in 8) which is suitable for 40 t capacity all-wheel drive (AWD) trucks. The 23 m wide ramp will be mined at 10% (1 in 10) gradient which is suitable for Caterpillar 777 rigid frame trucks.

The final design for Tap AB1/2 is shown in Figure 16.1 and the final design for Tap AB3 is shown in Figure 16.2.

amcconsultants.com

160

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The oxide rock is mostly free-dig whilst all fresh rock mined material is drilled and blasted. All ore is hauled to the Run of Mine stockpile where it is re-handled into the jaw crusher by a front-end loader.

Figure 16.1 Tap AB1/2 final design

Source: N. Spicer (Minesure Pty Ltd).

amcconsultants.com

161

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.2 Tap AB3 final design

Source: N. Spicer (Minesure Pty Ltd).

16.2.2.2Urucum

Past mining of the Urucum pits has recovered most of the oxide ore which has been trucked to the processing plant and processed. Mining of the Urucum sub-pits has been suspended until the processing plant has been modified to process higher proportions of primary ore. The primary ore is amenable to CIL processing however recovery is grind size sensitive so additional grinding capacity will be installed to enable throughput and recovery to be maintained at current levels.

The proposed pit final design is shown in Figure 16.3.

 

 

amcconsultants.com

162

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Figure 16.3 Urucum final design

Source: N. Spicer (Minesure Pty Ltd).

The total strike length (N-S) is approximately 2,200 m and the average cross-strike width is approximately 300 m. Relevant design data for four sub-pits is shown in Table 16.4.

Table 16.4 Urucum pits design data

Pit Length (m) Width (m) Pit base (mRL) Pit exit (mRL) Pit depth (m)
South 330 230 15 125 110
Central South 580 350 -29 130 159
Central North 500 290 59 179 120
North 880 300 31 151 120

The access ramp is designed to be eight metres wide with a gradient of 12.5% (1 in 8) for the bottom 36 m. It is then designed to be 14 m wide with a gradient of 12.5% for the next 24 m vertical. Thereafter it is designed to be 23 m wide with a gradient of 10% (1 in 10).

Ore is stockpiled close to the pits and then re-handled to the ROM pad for re-handling into the crusher.

16.2.2.3Urucum East

At the end of June 2017, no mining had taken place at the Urucum East deposit. The proposed final pit design is 300 m along strike and 180 m across strike. The design mines out the side of a hill so that the design has a depth of 40 m to the south and 190 m to the north. The access ramp is designed to be 14 m wide at a gradient of 12.5%. Ore is planned to be stockpiled close to the pits and then re-handled to the ROM pad for re-handling into the crusher.

amcconsultants.com

163

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The proposed final pit design is shown in Figure 16.4.

Figure 16.4 Urucum East final design

Source: N. Spicer (Minesure Pty Ltd).

16.2.2.4Tap C

The deposit has been mined previously and the proposed final pit design is shown in Figure 16.5.

The pit design extends over a strike length of 2 km with an approximate average width of 170 m and comprises a series of inter-connected pits. The access ramp varies in width but is generally 10 m wide at a gradient of 10%. Ore is usually hauled directly to the ROM pad for re-handling into the crusher.

Mining for all deposits is accomplished with a typical drill, blast, load, and haul cycle, using conventional truck-and hydraulic excavator equipment. Mining is undertaken by a mining contractor under the direction of BDR staff. The truck fleet comprises a mixture of AWD and rigid frame trucks. The rigid frame trucks are efficient at hauling large volumes of material and are mostly used on waste stripping. The AWD trucks are narrower than the rigid frame trucks so are mostly used to haul from the bottom of the pits up steeper ramps. This reduces the quantity of waste needed to be mined. Hydraulic excavators are used in backhoe configuration and range in size from 60 t up to 240 t. All equipment is diesel powered.

 

amcconsultants.com

164

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.5 Tap C final design

Source: N. Spicer (Minesure Pty Ltd).

16.3Contract mining

The main mine production equipment that U&M have selected for Tucano is outlined in Table 16.5 along with equipment which is now owned by the mine. Additional mining equipment support is provided by JS and Vale do Amazonas.

 

 

amcconsultants.com

165

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 16.5 Tucano mining fleet

Excavators Number Contactor / Beadell
Liebherr 9250 1 Beadell
Liebherr 9150 1 Beadell
VOLVO 700 1 JS Máquinas
VOLVO 700 1 JS Máquinas

HYUNDAI 220 BL

Hyundai 220

Hitachi (2500)

Hitachi (1200)

1

4

3

4

Vale do Amazonas

U&M

U&M

U&M

Total excavators 16  
Trucks    
CAT 777 3 Beadell
CAT 777 20 U&M
Komatsu 730 6 U&M
VOLVO (A35) 4 JS Máquinas
VOLVO (A35) 3 Beadell
Total trucks 36  
Dozers    
CAT D9 5 U&M
CAT D6 1 U&M
CAT D6 2 Vale do Amazonas
Total dozers 8  
Support Equipment    
Graders (Cat 16H, 14M 140) 5 U&M
Drills (Panther 1500, DX 680) 8 U&M
Loaders  (Cat 980) 4 U&M
Water trucks (Mercedes, Volvo) 4 U&M
Fuel truck 5 U&M
16.3.1Grade control and dig plans

The principal means of grade control is by RC drilling. Drilling is normally conducted on a 12 m x 6 m (y, x) pattern in the ore zone and 12 m x 12 m pattern outside of the ore zone. Holes are normally drilled to a depth of at least 24 m to enable testing of 20 vertical metres (5 working benches). Where access is difficult, RAB drilling performed by the geology department air track PW blasthole rig can infill drill angled holes to a depth of 8 m.

Channel samples of the pit wall are taken on every bench where the wall crosses the lode. At times face samples are taken along the face of an active bench to gain a better visualization and understanding of controls on mineralized structures. Areas of potential ore that do not have adequate sample coverage and cannot be tested with RC or RAB prior to mining due to access or timing issues have truck loads sent to the rehandle pad for further sampling. All RC, RAB, and channel sampling is undertaken on 1 m intervals, assayed and logged for lithology and weathering.

Grade control data is entered into an SQL database (Datashed) which is linked to an SQL (Torque) database in Minesight. The assays are composited to 2 m intervals coded by pre-defined estimation domains using a scripted routine. Top cuts are applied as part of the compositing process. Estimation is undertaken on a domain basis by OK on a bench basis using all data within range of the search ellipse for each domain.

amcconsultants.com

166

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The grade estimation is a scripted routine in Minesight which is fully editable for revised estimation parameters using a simple front end. Before each dig plan is produced, the composite file is updated and the estimation re-run. Dig plans are generated by first interpreting the drillhole assay grade and geology on 10 m sections. The cross-section of the ore polygon solid is designed based on the interpreted ore contacts and where dipping, either positioned as a vertical or dipping dig contact.

Following the review in cross-section, the ore polygons are adjusted in plan view and polygon solids created. These are then imported into a Minesight (MSIP) graphical database which calculates the volume, grade and tonnage from the geological model. MSIP also allows for the inclusion of dilution and mining recovery at the calculation stage with dilution based on lode width and the proportion of the ore polygon perimeter exposed to waste. Once the grade is calculated, the dig polygon is assigned to a grade category as defined in Table 16.6.

Table 16.6 Grade control grade ranges by material type

  Grade range Au (g/t) Destination
Grade category Pit: Tap AB / Tap C Pit: Urucum / Urucum East Oxide Sulphide
Very High Grade >1.60 >1.60 ROM Pad ROM Pad
High Grade 0.85 - 1.59 0.90 - 1.59 ROM Pad ROM Pad
Low Grade 0.65 - 0.84 0.75 - 0.89 ROM Pad Long Term LG Stockpiles
Marginal 0.50 - 0.64 0.50 - 0.74 Long Term Marginal Stockpiles Long Term Marginal Stockpiles

The pit topography is regularly coded to the model to generate accurate dig volumes and tonnages. In addition to gold ore, Iron Ore and Waste polygons are also generated. The iron ore block model has been integrated into the gold grade control block model and although iron ore does not currently hold value for GPR, it is stockpiled separately as a future resource.

16.4Underground mining
16.4.1Geotechnical and hydrogeological considerations

BDR completed a program of resource infill drilling below the Urucum North Pit. Most of these holes have been geotechnically logged for structural data, with the addition of one purely geotechnical hole to investigate the nature of the large structure located between the Urucum North and South pits.

The geotechnical data logged from these holes has been analysed to provide preliminary estimates of stable stope, development, and pillar dimensions using industry standard empirical techniques.

16.4.2Data used

Stability ratings have been calculated from data logged from the following holes (refer Table 16.7). The holes have been grouped into North, Central, and South areas to establish any trends in ground conditions. The positions of these holes, relative to the areas considered for underground mining, are indicated in Figure 16.6.

amcconsultants.com

167

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 16.7 Diamond drillholes used in the geotechnical analysis

Area Borehole ID
North FD1393 FD1409 FD1411    
Central FD1398 FD1401 FD1402 FD1410  
South FD1399 FD1400 FD1404 FD1405 FD1418

Figure 16.6 Long projection of Urucum North Underground looking west, showing geotechnical drillhole locations

Source: AMC 2016 PFS

16.4.3Major structures

A small number of significant faults have been logged. These appear to have two main orientations, sub-parallel to the lodes, but not directly adjacent to the mineralized areas, and striking north-northeast across the orebody.

The structures that are most likely to affect the mining and infrastructure development are the extensive pegmatite intrusions. Although the pegmatites are generally massive and competent, intense laminated structures can be present adjacent to the contacts, which may be destabilized by blasting. These intrusions take several forms:

amcconsultants.com

168

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Sub-vertical dykes: where these intersect the surface, deep (>200 m) weathering can be expected on the contacts, with the possibility of some water inflows.
Cross-linking structures between sub-vertical dykes: these can be heavily structured, both within and at the contacts of the structures with the host rock.
Sub-horizontal sills: these can be heavily structured at the contacts of the structures with the host rock.

The mine design should avoid placement of development in these areas where possible.

A north-northeast striking pegmatite intrusion has been identified between Urucum North and Central pits, which would be crossed by one of the proposed ramp routes. Logging of diamond drilled core through this feature indicates that below the base of oxidation, the ground is competent and should not present any difficulties to development. Cover drilling will be required to identify potential water sources or weathering on the contacts of the pegmatite.

16.4.4In-situ stress environment

No in-situ stress measurements have been completed at Urucum North underground mine.

It is not expected that high stress regimes will be present in the region. However, it would be prudent to carry out stress measurements at an early stage of the underground mine life to confirm this assumption. The results from the stress measurements should be analysed to review the proposed LOM sequence, particularly for deeper areas, as the planned mine depth is beyond 700 m from surface.

Although the strength of the rock mass means that major seismic activity is unlikely, as the mine develops deeper, there could be a significant potential for strain-bursting at the contacts between the different rock types, due to their different elastic properties.

16.4.5Weathering

Figure 16.7 presents the profiles both for the base of colluvium and for the base of weathering. The base of weathering is relatively shallow (less than 50 m over the orebody and less than 30 m over the country rock) and thus will have little effect on the underground mine. The main considerations will be the location of the portal, upper sections of vertical development (such as ventilation shafts), and the potential for much deeper weathering on the contacts of the pegmatite dykes and major faults.

The portal will be positioned within the open pit, below the level of the weathering, and vertical development will be positioned in areas of minimal thicknesses of weathered material, which would then either be dozed off or a pre-sink developed from surface to the top of the fresh rock.

amcconsultants.com

169

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.7 Cross-section showing weathering profile (Section 99,865 mN)

Source: AMC 2016 PFS.

16.4.6Ground water

Little ground water is expected to be encountered underground, with the exception of contact areas between the pegmatites and the country rock and the major cross-cutting faults. It would be prudent to carry out cover drilling when approaching any of these features.

16.4.7Rock mass classification

All holes recently drilled for the resource infill have been geotechnically logged for a distance of at least 30 m on either side of the mineralization. All holes were oriented, and logging was carried out before geological samples were removed.

The geotechnical information collected has been used to populate the mine design parameters for excavation dimensions and ground support requirements. Overall, the geotechnical data collected is of reasonable quality. Some problems have been experienced due to poor drilling practices in the earlier holes, but this has been addressed thus improving the reliability of orientation and run length in later holes.

The logging has provided sufficient data to be able to estimate both Barton’s rock quality index, Q and Bieniawski’s rock mass rating, RMR. These classifications allow the estimation of stable spans for stoping and development, as well as ground control requirements.

amcconsultants.com

170

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Safe development spans and support requirements can be estimated from Q, and it is possible to estimate a stable hydraulic radius to determine safe stope spans from a modified Q value (Q’), using the modified Mathews stability method (Potvin, 1988).

The results for the analyses are summarized in Table 16.8.

Table 16.8 Range of Q’ and RMR values

Zone / location Q’ RMR
Min. Max. Avg. Min. Max. Avg.
Hangingwall North 3.58 16.67 12.4 63 82 74
Central 2.78 96.71 33.04 63 84 74
South 3.13 200.00 41.79 60 87 73
Backs North 1.39 33.27 10.39 63 78 73
Central 3.12 266.67 55.71 63 82 75
South 1.39 100.00 25.79 72 87 80

The overall rock mass quality (either Q’ and RMR) is competent and does not vary much between hangingwalls and backs at the same locations.

AMC used the Q’ values to estimate the modified stability number (N’) and to determine the stable hydraulic radii (HR) for each of the stope zones. The same conservative rock mass condition (the lower bound of the average Q’ for the stoping zones) is used as Q’ for stope design. Table 16.9 presents the stope design parameters and the design limit of HR for an unsupported stable stope.

Table 16.9 Stope design factors and hydraulic radii

Q’ N' Maximum HR if unsupported (m)
12.5 28.1 8.2
16.4.8Stable stope dimensions

Figure 16.8 shows a summary of the maximum spans of stable stopes. In the example shown, if the spacing of the sublevel is 20 m (24 m floor to roof of the levels), an unsupported strike length of up to 50 m would remain stable, assuming no significant defects (such as major structures) are present. The 50 m will define either the rib pillar spacing, or the maximum strike length of the stope that can be left open at that height before backfilling the stope.

 

amcconsultants.com

171

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.8 Modified Mathews short-term stability estimate

  

 

Source: AMC 2016 PFS

16.4.9Pillar dimensions
16.4.9.1Crown pillar

The crown pillar between the base of the open pit and the upper underground excavation is critical to safe operations. This pillar must remain stable for the life of the excavation, either by design of sufficient size or ensuring sufficient confinement is provided to minimize pillar collapse. This may include additional ground control measures in the bottom of the pillar. Mining of blind up-hole stopes into the crown pillar should be avoided.

The height of the crown pillar will depend on the width of the stope beneath it. The minimum height to width ratio for the crown pillar should be 3:1. The actual height can be optimized by controlling the profile of the base of the pillar and with the use of ground control systems (cable bolts and shotcrete, for example).

It is essential that the crown pillar be formed with the minimum height in sufficiently strong (fresh) rock, and not within the weathered profile or colluvium horizons. The presence of deep weathering adjacent to any pegmatite contacts would need to be investigated.

amcconsultants.com

172

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.9.2Sill pillars

Sill pillars should be a minimum of 10 m high, with a minimum height to width ratio of 2:1. However, where stacked lenses, or wider orebody zones exist, the sill pillar height may need to be increased to maintain the 2:1 height to width ratio.

16.4.9.3Rib pillars

Rib pillars between open stopes along the strike of the same lens should be a minimum of 5 m high, with a minimum height to width ratio of 1:1. Pillars between lenses, where stacked lenses exist, should aim to form a minimum 10 m pillar. Where stacked lenses exist, the sequence of extraction should be from the hangingwall to the footwall. Stopes planned in the footwall of an existing stope should be limited in size, or small ore-rib pillars should be introduced to reduce the chances of inter-lens pillar failure.

16.4.10Excavation and support requirement
16.4.10.1Lateral development

Various development drive sizes have been proposed for use in the mine. The existing Q values indicate that the ground conditions will be suitable for the proposed development dimensions. Ground conditions are expected to be mostly good, which will result in low ground support requirements. Additional support might be required when crossing contacts between the pegmatites and country rock and crossing the major fault zones. Where poor ground conditions are encountered, additional support will be required, which should be designed by a competent person after inspection of the conditions.

Long term development

A standard pattern of five 2.4 m long rebar bolts per ring (nominally 1.5 m x 1.5 m spacing) is recommended, consisting of three bolts in the back and one in each shoulder. Taking into account the height of the ramp and cross-cut development, it will be impractical to either inspect or scale the backs of the drives. For this reason, it is highly recommended that either weld wire mesh (100 mm x 100 mm) or 50 mm thick fibrecrete is installed in the backs and shoulders of the ramp and cross-cut development, which can prevent the loose fall and save time in ground control maintenance (such as inspection, sound and check-scaling loose), thus to improve productivity.

Spot bolts may be required to secure wedges and smaller blocks formed by adverse joints in the backs or sidewalls.

In addition to primary support, cable bolts may be required for intersections with large span. It is recommended that all intersections be inspected by a qualified person, and the requirement for cable bolts be evaluated based on actual ground conditions.

Short term development

A similar pattern of bolts should be used in the ore drives, but these can be friction bolts and will not require mesh or shotcrete, except where ground conditions are poor.

Cable bolting might be required in sections of the orebody where brows of stopes are formed, particularly where open stopes remain. When double lift stopes are planned, the sub-level ore-drive may require hangingwall cables to reduce the effective unsupported span. This should be evaluated based on the stope dimension and actual ground condition.

amcconsultants.com

173

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.10.2Vertical development (ventilation shafts)

Ventilation shafts will be required in various locations throughout the operation. Specific investigation holes will be required to assess the local conditions and stability of these shaft positions. However, given the current information, it is expected that stable shafts could be excavated throughout the fresh rock zones.

Instability will be present in areas of the weathered and colluvium zones. Ideally, these layers should be avoided by placing the shaft collars in areas where this material has been removed. Where shafts are required to pass through these zones, pre-conditioning or shaft sinking methods may be required to reach the fresh rock horizon.

16.4.10.3Portal locations

Location and design of portals should be considered in fresh rock positions only. Specific investigation work may be required to ensure the locations will be suitable for the expected LOM, and that the layout of the decline does not pass into areas of significant deep weathering, or poor ground conditions related to currently undefined faults. Portal locations should aim to have a minimum of 5 m of sound, fresh rock above the completed portal excavation, and avoid being at the bottom of the open pit excavation where they might be vulnerable to flooding.

16.4.11Underground mine design basis
16.4.11.1Mining limits

The Urucum North Underground mine is based on the following battery limits:

Mining below Urucum North pit design of 11 March 2016 (des_uru_nth_march_a2016.dxf) and north of 99,300 mN. Mineral Resources based on the geological block model Reference: urucum_ug_resources2015_v17.dm (8 October 2015) provided by BDR.
LOM planning based on Measured and Indicated Mineral Resources.
Mineral Reserve estimates based on Measured and Indicated Mineral Resources only.
West of the mining license boundary at approximately 402,154 mE.
16.4.11.2Mineral Resource estimate

The Urucum North Underground Mineral Resource estimate is discussed in Section 14 of this report and is the basis for the Underground Mineral Reserve estimate. This resource is based on unweathered “fresh” material reported above a COG of 1.6 g/t Au and is shown in Table 16.10.

Table 16.10 Urucum North Underground Mineral Resource estimate - based on COG of 1.6 g/t Au

Mineral Resource category Tonnes Au grade (g/t) oz
Measured 258,125 4.09 33,943
Indicated 2,577,852 4.28 354,726
Total 2,835,977 4.26 388,669
16.4.11.3Stope optimization

The MSO module from Datamine Studio 3TM mine planning software has been used to produce the stope shapes and to generate stope inventories. The MSO process automates what a planning engineer would do manually, that is, generate stope string shapes on sections, link the string sections to create a stope wireframe shape, and then evaluate the wireframe against a block model.

MSO provides a stope shape that maximizes recovered resource value above a COG while also catering for practical mining parameters such as:

amcconsultants.com

174

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Minimum and maximum mining width.
Anticipated unintentional wall dilutions.
Minimum and maximum wall angles.
Minimum separation distances between parallel and sub-parallel stopes.
Minimum and maximum stope heights and lengths.

Figure 16.9 below summarizes the tonnage-grade curves for the MSO inventories based on various COGs. These MSO inventories include some out-lying (isolated) stopes that fall some distance from the main mineralized areas.

MSO parameters, including mining dilution parameters, are discussed in Section 16.2.4.

Figure 16.9 Tonnage / grade curves based on MSO stope shapes generated above 1.6 g/t Au COG

Source: AMC 2016 PFS

After the MSO process is complete, Mine24D has been used to estimate the development ore and stoping ore inventories. Mining recovery factors have only been applied to the stoping ore inventories.

16.4.11.4MSO estimates

Mining inventories are based on the MSO stope shapes generated using the following criteria:

Stope height generally 20 m (equivalent to level interval) although some stopes near the upper resource boundaries can be either 10 m or 15 m in height.
Stope length of 50 m along strike (divided into 2 x 25 m scheduling increments).
COG of 1.6 g/t Au.
Planned dilution of 0.5 m footwall plus 0.5 m hangingwall.
Minimum mining width of 2.0 m (plus 1.0 m of dilution).
Minimum pillar distance between parallel lodes 10.0 m.
Removal of isolated stopes requiring excessive development.

amcconsultants.com

175

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Note that the MSO estimates include outlying stopes (outliers) that, for mine planning purposes, have been excluded based on incremental access development costs. It should also be noted that this estimate has not allowed for modifying factors such as, ore losses to pillars (rib and sill), mucking recovery, and other external dilutions. These modifying factors have been applied to the detailed ore production schedules, generated using Earth Works Production Scheduling (EPS) software.

Table 16.11 summarizes the MSO parameters used (for reference).

Table 16.11 MSO parameters

Item Unit Value
COG for MSO stope shapes (before dilution added) Au (g/t) 1.6
Minimum mining width m 2.0
Dilution skin width - total m 1.0
Stope height 1 m 20
Stope height 2 from base m 15
Stope height 3 from base m 10
Stope increment - strike length m 25
Minimum transverse pillar width m 10
Include inventory within pit “reserve” pit design * Flag (1/0) yes
Conduct stope-adjacency smoothing Flag (y/n) no
Reference X start for stope shape grid & extent Easting | m 401,880 | 200
Reference Y start for stope shape grid & extent Northing | m 99,310 | 1,075
Reference Z start for stope shape grid & extent Elevation | m -590 | 800
Maximum weathered rock inside stope shape WEATH=5,000% 10
Block model: "urucum_ug_resources2015_v17" Version | date ugv17d #| 8 Oct 2015

Figure 16.10 shows the MSO stope shapes and the development designs in 3D, after removal of isolated stopes.

  

amcconsultants.com

176

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.10 3D view of mine design and MSO stopes - by lode number

Source: AMC 2016 PFS

16.4.12Access development

The key underground access features are:

A trucking portal centreline located at 402,053 mE, 100,062 mN, 173 mRL (floor level), at the north end of the Urucum North pit.
A ventilation portal centreline located at 402,037 mE, 99,744 mN, 136 mRL (floor level), at the south end of the Urucum North pit.
A decline system developed to the east of the lodes in the geological hangingwall that extends from approximately 173 mRL to -490 mRL. This splits into a twin decline system between 10 mRL and -390 mRL. The lateral coverage is approximately between 99,400 mN to 100,200 mN.
Two vertical ventilation rises exhausting to surface located at the north end of the Urucum North pit at 402,030 mN, 100,200 mE and 210 mRL.
16.4.12.1Decline stand-off distance

The decline has been designed based on the following minimum stand-off distances:

5 m east of BIF contact.
Minimum 15 m standoff between stope void and decline, down to 200 mbs.
Minimum 20 m standoff between stope void and decline, from 200 mbs to 400 mbs.
Minimum 25 m standoff between stope void and decline, below 400 mbs.

 

By keeping the decline east of the BIF unit, crosscut lengths are significant on some levels (>70 m). Once underground trials commence, and the location of the payable lodes is better understood as well as the ground conditions within the BIF, it may be preferable to develop the ramp closer to the stopes within the BIF unit itself.

amcconsultants.com

177

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

16.4.12.2Capital development estimates

The LOM capital development estimates are summarized in Table 16.12 and Table 16.13.

Table 16.12 Lateral capital development estimates

Lateral development - capital Dimension: W x H (m) Total length (m)
Decline 5.0 x 5.0 10,350
Decline stockpile 5.0 x 6.0 521
Egress access 4.0 x 4.0 1,155
Exploration drive 5.0 x 5.0 1,119
Fresh airway 5.0 x 5.0 60
Infrastructure 6.0 x 6.0 125
Level crosscut access 5.0 x 5.0 2,688
Level sump 4.0 x 4.0 384
Pump station 5.0 x 6.0 293
Return airway 5.0 x 5.0 2,386
Return airway oversized 6.0 x 5.0 565
Total   19,646

Table 16.13 Vertical capital development estimates

Vertical development - capital Dimension: Ø or W x H (m) Total length (m)
Egress raise 0.9 1,112
Fresh air raise 3.6 133
Return air raise 3.6 282
Longhole raise 4.0 x 4.0 742
Total   2,270
16.4.12.3Operating development estimates

The LOM operating development estimates are summarized in Table 16.14.

Table 16.14 Operating lateral development estimates

Lateral development - Operating Dimension: W x H (m) Total length (m)
Ore drive 4.0 x 5.0 15,252
Level stockpile 5.0 x 6.0 2,216
Total   17,468
16.4.13Mining methods

Based on the favourable ground conditions and relatively narrow ore body widths, Longitudinal Long Hole Open Stoping methods are preferred. Variations of Longitudinal Hole Open Stoping include:

Up-hole retreat
Down-hole benching

amcconsultants.com

178

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.14Up-hole retreat mining method

The Up-hole retreat method, as indicated in Figure 16.11, allows mining to proceed in a top down direction with stopes being blasted using up-holes and retreating back towards a centralized crosscut. Backfill of stopes can be delayed with rib pillars providing support to the void sidewall. Normally the large voids are eventually filled with un-cemented waste rock, to reduce the possibility of regional instability.

Figure 16.11 Long projection indicating up-hole retreat mining sequence

Source: AMC 2016 PFS

This method is recommended in the initial production build up-phase of the project, for the following reasons:

It does not require backfill until sometime after stopes are mined and even then, only if remaining pillars are stressed and begin to affect operations on lower levels.
Minimizes the amount of development required to be completed before production commences, unlike overhand benching methods where production commences on the lower level and proceeds in an up-dip direction.
The fact that backfill is not required as part of the mining cycle allows higher production rates to be realized.
The method is considered relatively simple to plan and execute.

The disadvantages of the method include:

Ore loss resulting from leaving behind ribs, resulting in an average ore loss of around 14%. (As the resource is developed and the grade distribution of the lodes becomes better understood it may be possible to position pillars in low grade areas, resulting in lower gold loss).

 

amcconsultants.com

179

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A significant amount of ore (approximately 70%) will need to be mucked using remote loading.
Stope fall-off can damage LHDs.
Often it is difficult to maintain a horizontal stope back at the top of an ore block, resulting in additional ore loss.
16.4.15Down-hole benching mining method

The Down-hole benching mining method indicated in Figure 16.12, allows mining to proceed in a bottom-up direction once access to the bottom levels is established. Generally, the method relies on down-hole drilling of blastholes. As each stope or level is mined it is back-filled with waste rock. Once a stope is filled, mining of the adjacent stope or stope on the next level above, can commence.

Pillar ore loss can be reduced for this method as pillars only need to stand until mining of the subsequent stope commences. Furthermore, some mines have removed the pillars altogether, by choke blasting up to the waste rock interface. The effect of blasting ore against the waste rock tends to compact the waste, allowing reasonable extraction of the abutting blasted ore with minimal waste dilution.

Figure 16.12 Long projection indicating down-hole benching mining method and sequence

Source: AMC 2016 PFS

 

amcconsultants.com

180

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

This method is recommended at Urucum North Underground in the lower parts of the mine for the following reasons:

Higher ore recoveries (estimated at 92%) can be achieved for the method as the backfill is placed much sooner compared to that for the Up-Hole retreat method, allowing smaller ribs (or even no ribs) to be left behind.
Allows down-hole drilling and charging of blastholes.
The method is considered relatively simple to plan and execute.

The disadvantages of the method include:

Ore production commences only when access to the bottom of an ore block is completed.
A significant amount of ore (approximately 70%) will need to be mucked using remote loading.
16.4.16Sill pillar recovery

In order to allow multiple mining fronts to be developed, allowing higher ore production rates to be achieved, sill pillars have been allowed in the design as indicated in Figure 16.13.

Figure 16.13 Sill pillars

Source: AMC 2016 PFS

The sill pillars are extracted after the stopes above or below have been mined and backfilled. Figure 16.14 indicates two options for sill pillar recovery. Both options are considered viable and should be trialled. The sill pillars are based on a standard level interval of 20 m equating to a sill pillar height of 15.5 m after allowing for the ore development.

 

amcconsultants.com

181

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Alternatively, it may be preferable to consider lower height sill pillars, e.g. 6 m to 10 m, that are left in-situ (unrecovered). It is AMC’s opinion that the preferred option can only be determined from mining trials and detailed stress modelling.

Figure 16.14 Options for sill pillar recovery

Source: AMC 2016 PFS

16.4.17Ventilation strategy

The mine will be ventilated by a Pull or exhausting type ventilation system. That is, the primary mine ventilation fans will be located at the primary exhaust airways of the mine and develop sufficient pressure to ensure all work places are supplied with the required fresh air and such that contaminants are removed to the exhaust air system and ultimately to the surface. Fresh air will be sourced from the surface through the main portal entrance and subsequently into the twin declines. Fresh air is also provided through an access drive into the open pit to provide an additional intake and ensure air velocities in the declines are not excessive.

Two primary return air raises are planned to breakthrough to the surface at the northern end of the mine, each with a single exhaust fan installation. As they are drawing from a common system, there is some redundancy provided should one be down for maintenance or breakdown. Internal return air raises are developed in tandem with each of the twin declines. A return air transfer drift is required to convey exhaust air from the southern internal return air raises across to the northern located primary raises.

The ventilation strategy is schematically represented in Figure 16.15.

 

amcconsultants.com

182

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.15 Long projection of the primary ventilation system

Source: AMC 2016 PFS

A total of 350 m³/s is planned for ventilation of the underground operation including the diesel equipment fleet, infrastructure, and personnel. This quantity reflects the requirements outlined in the Brazilian Regulatory Standards for Mining (Normas Reguladoras de Mineração) and a production rate of up to 700,000 tonnes per annum.

The main fan installations are planned to be located on surface and will be controlled with variable frequency drives to allow fluctuation in air volumes during the LOM. Ventilation network software modelling of the circuit has been undertaken to reflect the peak primary fan duties that could be reasonably expected.

Subsequent detailed scheduling confirmed maximum production rates of around 580,000 tpa, hence there is scope to optimize the ventilation requirements further.

16.4.17.1Level ventilation

Level distribution is designed such that fresh air will be sourced from the declines and travel along each level access drive where it is picked up by an auxiliary fan and duct installation for ventilation of work activities. Contaminated air from development and productions level activities exhaust back to the return air raise in the access drive of each level (refer Figure 16.16).

amcconsultants.com

183

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.16 Forced ventilation for a typical level

Source: AMC 2016 PFS

16.4.17.2Development ventilation

Ventilation will be required for all phases of the development drill and blast cycle, (e.g. drill, blast, muck, support, etc.). The ventilation requirement for development will need to:

Clear any residual dust generated (primarily by mucking).
Remove heat generated from diesel engines and, to a lesser extent, heat from electric / hydraulic equipment such as drill jumbos and bolters.
Dilute and remove diesel engine exhaust to acceptable levels.
Remove noxious gases after blasting.

The ventilation strategy for development uses a forced air fan (push) and duct system. To define the required ventilation flow for the excavation heading, a minimum flow of 0.078 m³/s per kW diesel engine power has been used (Brazilian Regulatory Standards for Mining).

For the decline development, it is assumed that there will be a maximum of one Atlas Copco ST 1030 loader (186 kW) and one Scania P20 truck (294 kW) in the decline heading. The total required airflow to be delivered to the end of the heading was estimated at 37.4 m³/s. This will be delivered through twin ventilation ducts with one duct extending to the face and the other to the truck loading bay. Each duct will require an auxiliary fan with a 90 kW motor.

For level development and also during the production cycle, it is assumed that trucks will not enter the ore drives and instead be loaded at the level accesses. As such, the mining levels will need to accommodate an Atlas Copco ST 1030 as the largest piece of equipment. At 186 kW, the ore drives will need to be ventilated with 14.5 m³/s airflow at the face. The auxiliary ventilation requirements for this is a single duct with 55 kW fan.

amcconsultants.com

184

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.18Ventsim modelling

The ventilation system for the Urucum North Underground Mine was modelled using Ventsim Visual™ Advanced.

The ventilation network for the Urucum North Underground Mine was analysed by importing the mine design from mine design software and then applying attributes for each of the airways relative to their dimensions, frictional resistance, length, etc. The airflow previously determined was applied to the network.

16.4.18.1Modelling results

AMC developed a Ventsim ventilation model for the Project for three primary purposes:

To validate the operability of the ventilation circuit ensuring airflow can be provided to all the required areas and during all phases of the mine.
To ensure compliance with design criteria and legislated ventilation requirements.
To determine fan duties and energy requirements.

Over the life of the mine, there will be a multitude of settings for the ventilation circuit, depending on the type of activities and their location throughout the mine. AMC modelled the circuit to reflect the peak primary fan duties that could be reasonably expected.

Table 16.15 Surface fan details

Description Specification
Type Horizontal mount axial mine fan
Configuration One exhausting fan per raise (two total fans)
Requirements 175 m3/s at 3,911 Pa raise collar total pressure (fan static pressure) on each raise
Each fan duty 175 m³/s at 4,464 Pa fan total pressure (air density 1.2 kg/m³ at 21.1°C)
Each fan motor 1,500 hp at 1,200 rpm complete with variable frequency drive
16.4.19Egress

In development of the ventilation strategy for the Urucum North Underground Mine, consideration has been given to the potential for mine emergencies. As such, the following criteria have been established:

Ramps will be in fresh air following their initial development.
On all levels, escape can be to either the ramp or to the escape way.
In each ramp, escape may either be up the ramp or down the ramp to a safe area.
Refuge Stations will be portable for flexibility of location at the most appropriate points in the mine. The number of portable Refuge Stations will be confirmed in later stages of design.
Whilst the primary means of communication will be by radio, a back-up stench system will be in place for introduction of ethyl mercaptan into both the portal and FAR.
16.4.20Underground mine production and development schedules

The basis for the scheduling includes:

Commence decline development on 1 January 2019 with the portal to be constructed at 172 mRL (floor level).
Focus on mining higher grade areas in 2021 and 2022.
Assume a top-down stope extraction sequence in upper levels to allow early production.

 

amcconsultants.com

185

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Assumes early development to the higher grade areas in the lower levels of Lode 1002 where down-hole benching commences in a bottom-up orientation.
16.4.20.1Development profiles and scheduling rates

The lateral development profiles (jumbo development), quantities and scheduling rates estimated by AMC are indicated in Table 16.16.

Table 16.16 Lateral development details

Type Development profile m x m Advance rate m/month Quantity (m)
Decline (including stockpiles) 5.0 W x 5.0 H 140 10,871
Egress access 4.0 W x 4.0 H 140 1,155
Exploration drives* 5.0 W x 5.0 H NA 1,119
Fresh airway access 5.0 W x 5.0 H 140 60
Service bays, magazine, pump stations, infrastructure 6.0 W x 6.0 H 60 418
Crosscuts 5.0 W x 5.0 H 140 2,688
Ore drives 4.0 W x 5.0 H 60 15,252
Return airway access 5.0 W x 5.0 H 140 2,386
Return airway access - oversize 6.0 W x 5.0 H 140 565
Level sump 4.0 W x 4.0 H 140 384
Level stockpile 4.0 W x 4.0 H 60 2,216
Total     37,116

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

* Exploration drives are indicated in some of the figures and tables, but they have not been included in the cost estimate.

The vertical development profiles, quantities, and scheduling rates estimated by AMC are indicated in Table 16.17.

Table 16.17 Vertical development details

Type Development profile Advance rate m/month Quantity (m) Comments
Egress - long hole 1.1 m dia. 70 1,112 Long hole
Fresh air intake - raisebore 3.6 m dia. 70 133 Development rate inclusive of setup and tear-down time
Return air raise - raisebore 3.6 m dia. 70 282 Development rate inclusive of setup and tear-down time
Return air raise - long hole 4.0 m x 4.0 m 60 742 Long hole
Total     2,270  

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

16.4.21LOM underground production schedule

The total projected waste development tonnes, and the annual production from the underground mine as a whole is provided in Figure 16.17. The production and development schedule is summarized in Table 16.18.

 

amcconsultants.com

186

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.17 Projected production profile

Source: AMC 2016 PFS

 

 

amcconsultants.com

187

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 16.18 LOM underground production schedule

Item Unit Year Y1 Y2 Y3 Y4 Y5 Y6 Y7 Y8
Ore and waste   Total 2019 2020 2021 2022 2023 2024 2025 2026
Waste mined kt 2,000 160 560 614 432 90 96 33 16
Production - stopes kt 1,894 3 155 229 343 373 281 271 239
Production - development kt 485 2 63 112 122 46 72 32 35
Total ore production kt 2,378 5 218 341 465 419 353 303 274
Production tonnage gold grade g/t 3.6 2.8 3.0 3.4 4.1 4.0 3.8 3.7 3.1
Mine development                    
Decline m 10,350 1,454 3,250 3,316 2,330        
Decline - stockpile m 521 81 160 160 120        
Egress access m 1,155 8 367 348 267 60 105    
Fresh airway m 60   60            
Infrastructure m 125 125              
Level crosscut access m 2,689 100 879 1,068 524 118      
Level sump m 384 16 128 144 96        
Pump station m 293 60 63 80 90        
Return airway m 2,386 130 601 810 505 170 170    
Return airway oversized m 565 204 361            
Ore drive m 15,252 65 1,660 3,150 3,679 1,811 3,002 1,084 801
Level stockpile m 2,217 42 755 811 509 100      
Total lateral development m 35,997 2,285 8,284 9,887 8,120 2,259 3,277 1,084 801
Major airways - raisebore m 416 219 197            
Major airways - long hole m 742 31 163 299 156 42 51    
Egress - long hole m 1,112   338 430 218 43 82    
Total vertical development m 2,270 250 698 729 374 85 133    
Backfill                    
Backfill placed kt 1,307 1.6 53.8 120.9 261.8 263.2 214.5 197.4 171.5
Total trucking M t-km 15.8 0.1 1.5 2.8 3.6 2.2 2.5 1.7 1.1

 

 

 

amcconsultants.com

188

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.22Underground mobile equipment

Equipment selection has been based on using mechanized underground mobile mining equipment that matches the proposed production rates and stope / ore drive dimensions. The main fleet will be supported by an appropriate ancillary fleet. Note that equipment models listed below are examples of the class of equipment, not recommendations for specific makes and models.

Diesel equipment such as service vehicles and trucks will be serviced on surface. Electric-hydraulic units (jumbos and production drills) and LHDs travel at slower speeds and therefore will be serviced underground for daily and weekly services and on surface for major services and overhauls.

Table 16.19 and Figure 16.18 show the units of equipment by year.

Table 16.19 Major equipment required over LOM

Summary 2019 2020 2021 2022 2023 2024 2025 2026
Development jumbos 1 5 6 5 2 2 1 1
Ground support rigs (bolters, shotcreter, etc.) 3 3 4 3 3 3 3 3
Production drills 1 1 1 1 1 1 1 1
LHDs 2 4 5 5 4 4 3 3
Underground trucks 1 2 4 5 3 3 3 2
Support equipment (ITs, Grader, etc.) 8 9 10 9 8 8 7 7
4WDs 4 4 4 4 4 4 4 4
Total 20 28 34 32 25 25 22 21

Figure 16.18 Major equipment required over LOM

Source: AMC 2016 PFS

 

amcconsultants.com

189

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.22.1Development drills / jumbos

Two-boom development drills (jumbos) such as Atlas Boomer 282 will be used to bore all development headings. As they will only be used for development drillhole boring, a longer feed rail can be used.

It may also be an option to use single boom jumbos and smaller LHDs in narrow ore lodes to try to minimize waste dilution. This advantage would need to weigh up against the lower productivities of both the single boom jumbos and smaller LHDs.

AMC recommends commencing operations with the larger equipment until the width of the ore lodes is better understood and the actual dilution in mining operations accurately determined.

16.4.22.2Production drills

Production drill selection has been based on the following criteria:

Preference for a basic drill which can be more easily maintained in Brazil.
No requirement for an operating cabin.
Average hole length of 15 m (with some holes to 20 m).
Ability to drill up-holes and down-holes for near vertical and narrow orebodies.
Hole diameter of 64 mm with ability to ream some holes to 115 mm diameter.

 

 

 

amcconsultants.com

190

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The Simba H1354 (refer Figure 16.19) would be suitable and has the following features:

Feed can be selected to suit 1.2 m, 1.5 m, or 1.8 m drill steels.
Electric hydraulic rig controlled using remote umbilical panel.
RHS rod handler (17+1 rods).
Total feed length is 3.97 m (assuming 1.8 m drill steels plus back hammer facility).
Ability to drill up-holes and down-holes.
All drilling is undertaken remotely using 20 m stand-off umbilical cord panel.
Slide table gives up to 3 m parallel hole capacity.

Figure 16.19 Simba H1354 production drill

Source: AMC 2016 PFS

16.4.22.3Underground trucks

Based on an average production rate of approximately 500 ktpa, AMC has considered the following trucks for haulage of ore and waste:

Volvo A35 articulated hauler. This 6WD truck is common in underground mines in Brazil. Its overall height is approximately 3.3 m with a tray height of approximately 2.9 m. As the truck is capable of withstanding poor roadway conditions, it is better suited to initial main ramp development and extensions of the ramps before a permanent well graded roadway is established.
Scania P420 rigid body truck. This 38 t truck is effectively used at Ferbasa’s Ipueira underground mine. The truck is inexpensive to purchase or maintain when roadways are well maintained and graded.
Scania 50 t version of the P420. Ferbasa have reported that the truck has similar dimensions to the P420 with the exception of the length, which will be extended by approximately 1.5 m.
Other articulated underground trucks such as the Caterpillar AD40.

From the trucks noted above, AMC has selected the Volvo A35 articulated hauler for the following reasons:

 

amcconsultants.com

191

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The Volvo A35 is commonly used in Brazil because of its proven performance, especially where poor ramp conditions exist.
AMC understands that the Volvo trucks can be purchased in Brazil, without attracting large import duties.

Once mining trial operations are underway, and decline roadway conditions are better understood, it may be beneficial to reconsider the truck fleet as any of the 4 trucks indicated above could be accommodated in the nominated decline profiles. The benefits of using the Scania P420 truck in particular include:

Lower cost - the Scania trucks cost approximately US$140,000/unit which is considerably less than the cost of articulated underground trucks.
Scania truck spares are common in Brazil, thus resulting in more available spare parts and lower maintenance costs.

Figure 16.20 shows a Scania P420 truck being loaded by a Volvo 120E front-end loader.

Figure 16.20 Scania P420 truck being loaded by a Volvo front-end loader

Source: Ferbasa

16.4.22.4LHDs

A fleet of 10 t LHDs is proposed at this stage. These LHDs are 2.6 m wide and approximately 2.4 m in height and can easily be accommodated within the 5.0 m H x 4.0 m W ore drives.

 

amcconsultants.com

192

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.4.22.5Ground support rigs

A dedicated ground support bolter such as the Atlas Copco Boltec M is recommended for ground support. This unit will be used for hole drilling, bolt installation, and mesh installation.

16.4.22.6Utility vehicles

Utility vehicles include the following:

Scaler (e.g. Scaletec UV 2 or Normet Scaler 2000).
Mobile rock breaker.
Integrated Tool carriers (ITs) for installation of services and transportation of materials.
Explosives charge-up units (e.g. Charmec).
Grader (e.g. Caterpillar 12H Grader) to maintain permanent underground roadways. If it is difficult to establish good roadways, it may also be necessary to deploy a vibratory roller periodically (e.g. every 6 months) to help compact the roads.
4WDs for transportation of technical staff and supervisors.
16.4.23Underground mine personnel

AMC estimates the following workforce for the underground project once it is in full production (not including 4 Expat trainers and additional resources to cover for absenteeism):

Underground mining equipment operators 91
Underground maintenance personnel 60
Management, supervision, and Technical Services 57
Surface maintenance 15
Underground service crews 13
Total 236
16.4.23.1Working shifts

Mine schedules have been based on 8 hr shifts (1 hr on surface and 7 hrs underground) as shown in Table 16.20.

 

amcconsultants.com

193

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 16.20 Underground workforce time allocation during shift

Activity Duration Notes
Average travel time - Home to site 30 min Unpaid time
Check in at mine gate 0 min Unpaid time
Travel gate to UG office 20 min Paid surface time
Clock in at lamp room 0 min Paid underground time
Shift change discussions and instructions 15 min Paid underground time
Travel to underground work place 15 min Paid underground time
Underground duties 3 hrs Paid underground time
Shift break 15 min Paid underground time
Underground duties 2 hrs 45 min Paid underground time
Travel to surface 15 min Paid underground time
Reporting of completed duties, consumables etc. 15 min Paid underground time
Clock out at lamp room 0 min Paid underground time
Change / shower 20 min Paid surface time
Travel gate to UG office 20 min Paid surface time
Check out at mine gate 0 min Unpaid time
Average travel time to home 30 min Unpaid time
Total paid underground time 7 hrs  
Total paid surface time 1 hr  
Total underground time working on job 5 hrs 45 min  
16.4.23.2Rosters

The underground operations personnel are to work a six panel, three shift roster. Features of this roster are:

Continuous operations - 24 hrs per day, 365 days per year, three shifts per day.
7 hrs per shift plus 1 hr on surface, with a maximum of 5 hrs 45 min working at the face.
19 days on, 9 days off basis.
28 days annual leave.

Expats will work a four panel, two shift roster. Features of this roster are:

Continuous operations - 24 hrs per day, 365 days per year, two shifts per day.
12 hrs per shift.
14 days on, 14 days off basis.
14 days annual leave.

It is expected that senior staff will work a non-continuous roster of 5 x 12 hr shifts followed by 2 days off, with 20 annual leave days per annum.

Table 16.21 indicates the break-down of the management and supervision, technical services, surface maintenance, and underground service crew employees (excludes underground equipment operators and maintenance personnel) for the underground project once in full production.

 

amcconsultants.com

194

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 16.21 Mining department employees - excluding UG equipment operators and maintenance personnel

Position Class Responsibility / duties Max number
Mining  
UG Manager A Overall responsibility of underground operations 1
Senior Engineer B Responsible for all planning / scheduling, reserve estimates, and annual budgets 1
Mining Engineers C Shorter term planning and scheduling, drill and blast, vent etc. 3
Sen Geotechnical Engineer B Responsible for GCMP and compliance 1
Technicians D Prod reporting, vent monitoring etc. 8
UG Foreman B UG supervision / management - for each shift 6
UG Workers UG6 Building of vent barricades, clean drains etc. 15
Geology  
Senior Geologist B Responsible for grade control, mineral resources and annual budgets 1
Geologists C Grade control, resource models 2
UG Geology Technicians F Sampling, core cutting / logging 9
Survey  
Surveyor C   3
UG Survey Technicians E Assist surveyors 7
Surface workshop / stores  
Manager A Overall responsibility of underground equipment and annual maintenance budgets 1
Senior Engineer B Maintenance planning, spares ordering 1
Engineers / planners C Planning and supervision of fitters / electricians 3
Artisans E Fitters / electricians 10
Expert Trainers Expat On site trainers 4
16.5Underground infrastructure
16.5.1Underground access

The key underground access features are:

A trucking portal centreline located at 402,053 mE, 100,062 mN, 173 mRL (floor level), at the north end of the Urucum North pit.
A ventilation portal centreline located at 402,037 mE, 99,744 mN, 136 mRL (floor level), at the south end of the Urucum North pit.
A decline system developed to the east of the lodes in the geological hangingwall that extends from approximately 173 mRL to -490 mRL. This splits into a twin decline system between 10 mRL and -390 mRL. The lateral coverage is approximately between 99,400 mN to 100,200 mN.
Two vertical ventilation rises exhausting to surface located at the north end of the Urucum North pit at 402,030 mN, 100,200 mE, 210 mRL.

At this stage AMC has assumed a larger dedicated Personnel Carrier (or similar) will transport the underground workforce from surface to underground, together with smaller 4WDs. Materials will also be transported via the decline predominantly using Integrated Tool carrier (IT) type underground vehicles.

 

amcconsultants.com

195

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.5.2Surface ventilation fans

Surface fans will comprise two 560 kW radial parallel fans. Fans have been based on airflow modelling.

16.5.3Change rooms and lamp room

Three change rooms will be established for the following persons:

Underground workforce (40 per shift).
Managers and supervisors (10 per shift).
Visitors (10 per shift).

Each change room will have the following facilities:

Clean changing area including lockers.
Dirty clothes changing area including lockers and clothes drying racks.
Showers, toilets, and wash basins (the underground workforce will shower before proceeding home at the end of each shift.

Adjacent to the change room will be a lamp room capable of accommodating up to 200 lamps.

16.5.4Underground mine offices

Offices will be established for the following functions and persons:

Geology and survey
Engineering and mine planning
Operations control
Electrical and mechanical engineering
Management and supervision

The operations control will comprise of a mine clerk who will maintain all production reporting data, shift bosses (present during shift change), Health and Safety reporting, and mine communications.

This study assumes that the change rooms, lamp rooms, and offices will be rented for the duration of the project and will be delivered to site as trailer mountable / dismountable units. A lower cost alternative might be to find a local contractor to build these structures on site.

16.5.5Surface workshop

Surface workshop will be used for regular servicing of all trucks and service vehicles (scissor lift, ITs, and light vehicles). In addition, the major maintenance of underground jumbos, production drills, and LHDs will also be undertaken at this workshop. The workshop will be a basic structure consisting of two stacked containers on either side of an arched undercover area. Any major overhauls requiring additional facilities can be undertaken at the existing open pit maintenance facilities.

Surface workshop will be constructed with the following facilities:

10 t overhead / gantry crane.
Offices for supervisors.
Toilets and wash basins.
Workshop area to accommodate up to two trucks, LHDs, or jumbos.

 

amcconsultants.com

196

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Refuelling station and storage.
Wash-down pad and facilities.
16.5.6Mines rescue centre

A mines rescue centre will be constructed to accommodate:

First aid room
Mines rescue and training room
16.5.7Mine portal

A portal will be established at the base of the Urucum North pit. The portal will be established in fresh rock with basic support (no steel sets or concrete anticipated).

16.5.8Water supply

Water will be supplied from the open pit mining facilities and stored above the portal area from where it will be gravity fed through the decline to underground. AMC has allowed for four 48 kL poly tanks as water supply header tanks in its cost estimates.

16.5.9Existing facilities

Both the existing open pit explosives magazine and warehouse facility will be used for the underground project.

16.5.10Power supply and distribution

Medium voltage electrical power (e.g. 4,160 volt) will be supplied to the underground via both the declines using separate feeder circuits connected to the site main substation. Each of the two feeders will continue down the underground access declines.

As development progresses, the first of the feeders will be connected to a fused medium voltage switchgear unit located on the level where mining activity will occur. This medium voltage switchgear unit will supply power to a Power Distribution Centre (PDC) unit located on that same level. This PDC will step down the voltage to 660 volts and distribute power to any mining equipment, pumps, fans, small motors, and lighting demands necessary to permanently service that level and nearby sublevels.

The medium voltage switchgear unit will also supply up to six portable Mine Power Centres (MPC) located throughout the level. Each of the portable MPCs will be fed from the medium voltage switchgear via trailing cables and will step down the voltage to 660 volts to supply power to any mining equipment, pumps, fans, small motors, and lighting demands required on a temporary basis to develop and mine the level.

As development continues downward, an additional feeder cable will be installed with a permanently placed medium voltage switchgear unit and a PDC unit installed on main levels. With both ramps being developed at the same time, this equipment could be powered from either ramp.

When the lower interconnected level is reached, a medium voltage switchgear unit and PDC unit will be placed along with two tie switches that connect the two independent power feeds coming down each ramp. This will allow power to be supplied via either feed.

 

amcconsultants.com

197

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.5.11Water supply and distribution

The mine has an existing fresh water system set up for open pit mining and processing operations.

Underground requirements are estimated to peak at around 7.6 l/s assuming a production rate of around 580 ktpa and would be met by 4” steel service piping down the declines with occasional pressure reducing valves.

16.5.12Dewatering

The Urucum North underground dewatering system is based on a series of sumps and submersible pumps along the decline. Each of the sumps is 80 m apart vertically. Each sump discharges into the next in series until discharging out the portal into the open pit dewatering system.

Intermediate sumps on 20 m levels drain to each major sump below via drain-holes.

16.5.12.1Pump selection

Given the low ground water inflows (expected), pumps have been selected that can generate a carrying velocity in the 6” dewatering lines. This provides a capacity that is in excess of any peak drilling water consumption. Sumps are sized to provide a 30 min on cycle for the design flow rate.

All pumps would be the same model and would be readily interchangeable. Space would be provided in the sumps for inline spare capacity. As well, the system can be quickly expanded if additional dewatering requirements are encountered during development, by installing additional pumps.

The pump selected is a submersible Weir Hazleton SHW, more commonly known as a “Warman” style centrifugal submersible slurry pump, with a nominally 50 hp motor.

16.5.12.2Sump design

Sumps are split into a clean and dirty side. The dirty side is accessible from the ramp with mobile equipment in order to allow for cleaning if required. The clean side and dirty side are separated with a low weir.

To ensure mud build up on the dirty water side does not become excessive, AMC recommends LHDs muck one to two buckets on each shift (depending on rate of mud build up) and the small quantities of mud mixed in with development waste (or ore if required) for haulage to surface. The dirty side must never be allowed to build up to the extent where a major mud clean-up is required (major clean ups can result in LHD damage when the water / mud levels are above the LHD axles).

A submersible pump is hung from chain hoist and monorail to allow it to be removed and serviced. Bypass valves would be installed at the base of the weir to allow the two sides to be connected for maintenance work.

Figure 16.21 shows a section of a proposed sump layout.

 

amcconsultants.com

198

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.21 Section of proposed sump layout

Source: AMC 2016 PFS

The sump is intended to have a clean water capacity of 50 m3.

16.5.12.3Dewatering system

Pumping estimates have been based on a pumping rate of 10 l/s, for both the north and south declines. This rate is based on both ground water inflows and manmade water (drilling / flushing water, washing down, etc.).

Eight sumps would be required along the north decline and six stations would be required along the south. Depending upon the mine schedule, some sumps could have drain holes that allow sumps to be bypassed as the mine development proceeds, although this would need to be confirmed during more detailed future work.

Mine dewatering will take place along the decline through six-inch standard steel lines using quick-couplings. Pumps would be connected to the dewatering line via flexible connectors. Backflow checks are required downstream of each pump.

As the decline is advanced the dewatering lines would be hung and used during development. As each sump is excavated and constructed, the dewatering lines remain in place. Discharge would take place out the portal into the open pit dewatering system.

16.5.13Compressed air

Compressed air will be supplied by local area portable compressors.

The portable compressors will be electrically powered using the same jumbo plugs and jumbo boxes as other mobile equipment, such as the jumbos and bolters. AMC recommends that two compressors be available on site to accommodate the following potential demands:

Meet the elevated pressure requirements for any ITH drill activities.
Powering mechanized raise climbers (if required).

 

amcconsultants.com

199

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Miscellaneous activities such as spot bolting with airlegs, powering air tools.

All mobile drilling equipment, including jumbos, long-hole drills, and bolters will be equipped with on board compressors.

16.5.14Emergency egress

The emergency egress will be developed in 40 m sections, connecting to every second level. AMC has assumed this will be undertaken using contract airleg miners; however, raise climbers such as alimaks may also be used as an alternative. Lateral development between the crosscut and the emergency egress has been assumed to be developed using development jumbos; however, short handheld development should also be considered if the raises are mined using airlegs.

Once the airleg rise is completed, a modular escapeway system will be installed between the two levels. The system will be extended as each second level crosscut is developed. The modular escapeway ladders are fully caged, with rest landing spaced at 6 m intervals, while inclined at 70º or steeper.

16.5.15Refuge chambers

AMC has made allowance for four 12-person refuge chambers for use during the development phase of mine as the escapeway system is being established or where a second means of egress cannot be provided. Figure 16.22 shows a typical example of the proposed chamber.

 

 

amcconsultants.com

200

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 16.22 MineArc refuge chambers

  

Source: AMC 2016 PFS

16.5.16Underground communications

In order to keep capital costs to a minimum, AMC has assumed a simple and cost effective leaky feeder communication system will be installed underground. This system is based on 2-way radios mounted on every piece of mobile equipment and in strategic locations.

16.5.17Future data management systems

More expensive fiber-optic data systems today are able to control the following:

Secondary ventilation fans (controlled from surface).
Dewatering pumps (controlled from surface).
Underground management reporting (production and development statistics, etc.).
Underground communications.
Surface fans.
Production and development blasting.

Such a system should be considered once initial mining trials prove to be affective and would be based on a network of fiber-optic cables between stations. Information collected from equipment sensors, tele-communication terminals, and voice would be transferred to the fiber-optic facility and routed to surface, as well as to other points within the mine. The benefits of such a system are reduced ventilation costs by running ventilation based on demand and better project management using up to date underground data such as shift reports, etc.

 

amcconsultants.com

201

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

16.5.18Underground service bay

Daily maintenance of Jumbos, LHDs, and production drills will be completed either at the face, or in an underground service bay located close to mining activities. Trucks and service vehicles capable of travelling at higher speeds will be serviced on surface.

 

 

 

amcconsultants.com

202

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

17Recovery methods
17.1Summary

The existing Tucano Mill consists of a jaw crusher feeding a single-stage, semi-autogenous grinding mill (SSAG), with the ore then being treated in a CIL plant. GPR is currently planning on mining and treating approximately 3.6 Mtpa of ore through the process plant, elution, and electrowinning facility to produce around 140,000 to 150,000 ounces of gold per year. The plant treats an ore blend of 80% oxide and 20% sulphide. The Tucano Expansion Project is currently in construction and is discussed in Section 13. Plant throughput will be maintained at 3.6 Mtpa. The expanded plant is described as follows:

17.2Crushing and ore stockpiling

Ore is delivered to a run-of-mine (ROM) pad where ore of oxide and sulphide are stockpiled separately on fingers of specified grade ranges. Ore is fed to the crusher hopper by means of a front-end loader to achieve the planned sulphide / oxide blend and grade for the day. A vibrating grizzly allows the finer, sticky oxide ore to bypass the crusher. Crushing is achieved using a 1,220 mm x 1,070 mm single toggle jaw crusher with a closed side setting (CSS) of 125 mm. In addition to the jaw crusher, a separate Spent Ore Feeder is located in the emergency stockpile area to facilitate the feeding of Spent Ore direct to the SAG mill. A surge bin with 30 min residence time and a diversion chute to an emergency stockpile feeder is located halfway between the crusher and the SAG mill.

17.3Milling and classification

Grinding is achieved with a SSAG mill with a 7 MW single-pinion drive, a diameter of 7.32 m and an effective grinding length (EGL) of 7.95 m. Cyclones operate in closed circuit with the mill to produce a product size which is currently coarser than 80% < 105 μm. After construction of the 6 MW ball mill, the grinding circuit will achieve a finer grind of 80% < 75 μm.

17.4CIL

Cyclone overflow from the grinding circuit is screened in the trash screen and is then pumped to the CIL circuit. The CIL circuit consists of six 2,650 m3 (live volume) carbon contactors, located south of the reagent storage area on the area formerly occupied by the rich solution pond from the heap leach operation. A seventh tank will be installed as part of the current mill expansion. It will not be fitted with a screen and will operate as leach tank only, ahead of the existing CIL.

The six existing CIL tanks operate in series. Launders connect the tanks to allow slurry to flow by gravity through the tank train. All tanks are fitted with bypass launders to allow any tank to be removed from service for agitator or screen maintenance.

Each tank is fitted with a 110 kW mechanical agitator to ensure uniform mixing. Air is currently sparged into each leach tank to provide adequate oxygen for gold dissolution. An oxygen plant will be constructed during the expansion to provide increased recoveries at the higher proportion of sulphide material in the ore blend.

Each CIL tank is fitted with a single 12 m2 mechanically-swept, wedge-wire inter-tank screen to retain carbon. The style of inter-tank screen selected is known as a “pump screen”, which allows each of the CIL tanks to be installed at the same elevation, in contrast to the stepped arrangement used for conventional cascade carbon-in-pulp (CIP) plants. This simplified the civil engineering requirements of the CIL area. Barren carbon enters the adsorption circuit at the last tank, CIL Tank 6, and is advanced counter-currently to the slurry flow by moving slurry and carbon from CIL Tank 6 to CIL Tank 5 using recessed impeller carbon-transfer pumps. The inter-stage screen in CIL Tank 5 retains the carbon and the slurry flows by gravity back to CIL Tank 6. This counter-current process is repeated until the carbon reaches CIL Tank 1. A single recessed-impeller pump is used to transfer slurry to a loaded-carbon recovery screen. The carbon reporting as screen oversize flows to the carbon transfer column and the screen undersize returns to CIL Tank 1.

 

amcconsultants.com

203

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The loaded carbon is washed with process water in the carbon transfer column to remove slimes prior to the elution circuit. An eductor, using raw water, is used to transfer the washed carbon to the existing desorption circuit. Barren carbon returning to the adsorption circuit from the carbon regeneration kiln is screened over a vibrating screen to remove fine carbon which is then collected and stockpiled for processing off site. The sized and regenerated carbon reports directly to CIL Tank 6.

Sodium cyanide (NaCN) solution is metered into Leach Tank No. 1 and CIL Tanks 1 and 2 via a ring main system. Final pH adjustments are made by the addition of lime to the CIL feed box from a lime slurry ring main system. Tailings slurry from the last CIL tank flows to the vibrating carbon safety screen to recover any carbon that may be present due to damage, wear, or incorrect installation of the final stage inter-stage screen. Carbon recovered on the screen is delivered to a bulk bag for re-use. Tailings discharging from the carbon safety screen underflow are transferred via gravity to the cyanide detoxification circuit. The leach and adsorption area is provided with three spillage pumps, which deliver any spillage in the area back to the process. Maintenance of the CIL tanks and agitators is achieved using an overhead crane.

The new leach tank and the six CIL tanks, give the combined CIL tanks a total residence time of just over 24 hrs at the expected slurry density.

17.5Tailings

Tailings are deposited in the West Pond area to the north of the plant. The use of the West Pond involves pumping the tailings about 3.6 km and the return water initially about 2.7 km and later up to 5.5 km. An air / SO2 cyanide destruction circuit, using sodium metabisulfite (SMBS), lime slurry, and copper sulphate (Cu2SO4), and consisting of two tanks in series with a total residence time of 60 min, lowers the cyanide concentration before discharging to the West Pond TSF. The detoxified tailings will leave the circuit at approximately 38% solids. Water is recovered from the TSF and pumped back to the process plant for consumption or neutralization and discharge. Natural degradation and dilution in the dam reduces the cyanide level further in the return water to approximately 10 ppm total cyanide. The majority of this water is re-used in the process plant. However, as the site water balance is positive, a portion of this water needs to be discharged to Igarapé William (William Creek).

17.6Elution

The existing Pressure Zadra elution circuit and gold room were already in place when BDR acquired the plant from the previous heap leach operation and the CIL plant was configured to use these facilities. The elution columns are primed with a solution of 0.1% cyanide and 1% caustic soda that is prepared in the electrowinning solution tank. This solution is recirculated through the elution columns at 135°C to promote the elution of gold ions that are adsorbed in the micro pores of the loaded carbon. The heating of the recirculating solution is provided by a 720 kW electrical elution heater. The current elution circuit is sized to treat 4.8 tonne of carbon per day.

17.7Carbon regeneration

Once the acid wash cycle is complete, the carbon is educted to the kiln feed hopper, where the carbon is screw-fed to the kiln dewatering screen, to dewater the carbon to 50% w/w solids. The undersize of the kiln dewatering screen is brought to grade, to be collected by the acid wash area sump pump. The kiln dewatering screen oversize reports to the kiln feed hopper. Carbon is withdrawn from the kiln feed hopper by a screw feeder and fed to the carbon regeneration kiln. Carbon regeneration is achieved at a temperature of 700°C. After regeneration, the barren carbon is discharged into the carbon quench tank to reduce the temperature of the carbon to room temperature. The barren carbon is then transferred back to the CIL circuit. The carbon regeneration kiln acquired from the previous heap leach operation has been extensively refurbished by BDR.

 

amcconsultants.com

204

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

17.8Electrowinning and gold recovery

The rich solution leaving the elution columns passes through two heat exchangers, arranged in series, to reduce the solution temperature, then through a cyclone separator to the electrowinning feed tank. The solution flows from the electrowinning feed tank through a bank of two electrowinning cells, where the gold in the solution is deposited on the cathodes within the cells. The weak solution leaves the electrowinning cells and returns to the electrowinning solution tank. This solution is then pumped back through the elution heater to the elution columns. The solution is recirculated through this closed circuit for 12 hrs, until the disposition of gold onto the cathodes is complete. At the end of the elution cycle, the carbon is transferred to the acid wash column. The barren eluate solution is pumped from the electrowinning solution tank back to the CIL circuit.

The acid wash cycle consists of a six-hour acid wash, in which 15% hydrochloric acid (HCl) is recirculated through the column, followed by a two-hour water wash. The HCl is delivered to the acid wash column by a dedicated acid wash HCl tank and pump set, located in the desorption area. The 15% solution is prepared by the addition of 33% HCl from the main acid storage tank, with dilution provided by raw water. Wash water is added to the acid wash tank from the main raw water supply. The original design of the elution circuit included a four-hour neutralization cycle using sodium hydroxide (NaOH). However, this step was deemed to be unnecessary during the operation of the heap leach plant and was decommissioned.

The gold room was retained from the previous heap leach operation existing operation and consists of a bank of two electrowinning cells. During the elution process, the stainless-steel wool cathodes within the cells become loaded with gold. At the completion of the elution cycle, the sludge containing the gold, which is weakly adhered to the cathodes, is dislodged with a high-pressure water spray. The sludge is dried in a drying oven before being direct smelted with fluxes in a furnace. There are two operating furnaces that were retained from the previous heap leach operation, a gas-fired furnace and an electric furnace. The doré metal and slag separate in the furnace, the slag is poured off to slag pots and the doré metal is poured into bars. Doré bars are cleaned, weighed, stamped, sampled, and then stored in a safe contained within a strong room, while awaiting dispatch.

 

 

amcconsultants.com

205

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18Project infrastructure
18.1Context and regional infrastructure

The Tucano site is located approximately 120 km Northwest from Macapá, the capital of Amapá state, in the Northern coast of Brazil.

The site is relatively remote and, for the development of the Tucano property, GPR and its predecessors took advantage of the existing infrastructure built in the late 1950s for the Serra do Navio manganese operations, 15 km Northwest from the Tucano site, and its upgrades, mainly established during the 1970s.

The main existing infrastructure in the vicinity of the Project consists of the towns at Serra do Navio and Pedra Branca do Amapari, the road from Macapá to Serra do Navio, the hydropower facilities and transmission line from the Coaracy Nunes complex in the Araguari river, approximately 70 km to the West from the Tucano site, the railway from Macapá do Serra do Navio, now inactive, and the port at Santana.

Macapá and the Santana port, approximately 10 km to the Southwest of Macapá, are located in the North canal of the Amazon river. The Santana port can accommodate relatively large ships, as it was built for bulk materials handling and has been in use until recently to handle iron ore from the Zamin property, adjacent to the Tucano site, to the Southeast.

Macapá is 330 km Northwest from Belém, the capital of the state of Pará, in the South canal of the Amazon river. Belém has approximately 1.5 million inhabitants and has a fairly developed industry. It is well connected to the industrial regions in Brazil Southeast and the main region’s hub.

Most of the industrial supplies and bulk materials required for Macapá and the Project are sourced in Southeast Brazil, transported via roads to Belém, where trucks are ferried to Macapá, disembarking in the Santana port.

Macapá has a population estimated as of approximately 474,000 inhabitants. The state of Amapá, in the North margin of the Amazon river is considerably less developed than its southern neighbour, Pará. Most of the industrial development of the state was first driven by a number of mining and agro-industrial projects established since late 1950s.

There are two small towns near the Tucano site that house most of the Project employees and their families: Serra do Navio, established as a mine camp to accommodate the manganese operations personnel and their families in the late 1950s, with approximately 5,100 inhabitants and Pedra Branca do Amapari, 30 km via road from the Project to the Southeast, with a population of approximately 13,000 people.

The Coaracy Nunes hydropower facilities at the Araguari river have a capacity up to 78 MW and are operated by the state-owned CEA, controlled by Eletronorte. The facilities were developed in the mid-1970s to support the Serra do Navio and Jari projects providing a reliable and affordable alternative to diesel generated energy for the state of Amapá, which has no links to the remainder of the national grid in Brazil. The 69 kV transmission line from the Coaracy Nunes complex to Serra do Navio is approximately 70 km long and was installed in the South margin of the Araguari river to its junction to the Amapari river and then follows the railway path to Serra do Navio in the South margin of the Amapari river.

 

amcconsultants.com

206

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.2Site access and logistics

The mine site is located approximately 200 km from Macapá. Access to Serra do Navio via road is well established since the implementation of the manganese operations in the late 1950s and, later, the upgrade for the construction of BR-210, Rodovia Perimetral Norte in the mid-1970s. Open pit mining operations at Tucano commenced in 2012, when a dedicated road was upgraded from Pedra Branca do Amapari to the Mine. This access comprises:

Sealed road for approximately 100 km, from the port town of Macapá towards Porto Grande.
Unsealed road from Porto Grande to Pedra Branca do Amapari, approximately 70 km.
Unsealed road from Pedra Branca do Amapari to the site, developed specifically for the Project for approximately 30 km.

The journey from Macapá takes approximately four hours by car during the dry season and up to six hours during the wet season, depending on the condition of the unsealed roads. The unsealed roads are passable all year around and no blockages are experimented, except for the road maintenance.

The main concern for the transport of personnel, bulk materials, parts, and other supplies is the existence of various bridges along the route, mostly built using wood as primary construction material and whose capacity is limited to 45 t of total load (carriers plus the deadweight). Most of the bridges have been upgraded recently, allowing for a reliable means of transport to the site. The load limitations have not been a problem for the mine operation or the plant upgrade, as most of the equipment parts to be erected are lighter than 20 t to 25 t, average deadweight transported per trip.

Diesel for the operation of the mining fleet and power generation is the main bulk material transported to the Mine, approximately 3 ML are consumed per month (equivalent to approximately 80 tpd) as of the first quarter of 2018. This demand would decrease by half once the power source is converted from diesel to hydropower. Lime for neutralization follows, with an average consumption of approximately 30 t per day, sourced from São José da Lapa, Minas Gerais. Cyanide, sourced from Bahia, is transported in briquettes and hydrated at the mine site at a rate as of 250 t per month. Balls for milling, representing approximately 150 t per month, and activated coal for the CIL process, at an approximate rate as of 24 t per month, complete the major bulk consumables. The average time spent by general cargo via road from the Southeast of Brazil to the mine site takes 12 days to be delivered, once consolidation takes place, totalling less than 20 days, including consolidation, while dedicated cargo takes 12 days to 15 days to be delivered at the Project.

A helipad was constructed near the CIL plant and is used to transport product and emergency removal of personnel. The Tucano mine site is also serviced by a 1,100 m airstrip located approximately 800 m from the main gate that serves as a backup. Charter flights from Macapá to the mine take about 50 min.

18.3Mining and support facilities

The following facilities are located in proximity to the CIL Gold Plant:

Central administration building and medical facility.
Geology, survey, mining engineering, supply, environment, and safety offices.
Core shed and exploration sample preparation facility.
Nursery.

The mine is primarily operated with 250 t class excavators (Liebherr 9250s, Hitachi EX2500s), 100 t class trucks (Caterpillar 777s) and 40t articulated trucks, supported by 400 HP and 320 HP class bulldozers (Caterpillar D9s and D8s), 4” drill rigs and 16 feet class graders (Caterpillar 160), plus assorted support equipment.

 

amcconsultants.com

207

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The heavy machinery and light vehicle workshops with adjacent warehouse storage facilities, tire shop, refuelling, and washing bays were constructed to high standards and were upgraded in 2012.

The mine planning, administrative, and messing facilities are also located in the workshop area together with the mine control and dispatch room.

An explosives magazine and accessories storage constructed to standards are located at convenient distance from the other industrial installations. More recently, a factory for producing emulsion explosives was built and is operated by the explosives supplier. The installations are fenced and surveyed by armed guards and cameras permanently.

18.4Sub-contractor facilities

U&M will coordinate and undertake all heavy machinery maintenance at the main workshop alongside of the main supply warehouse. McKay Drilling, the geological drilling contractor, has a separate workshop (and storage sea container near the MACA workshop).

Figure 18.1 U&M workshop facilities

 

 

 

amcconsultants.com

208

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.5Process plant

The processing plant and administration facilities consist of:

Plant administration buildings.
Plant workshop area.
Power supply and distribution.
Sample preparation and assay laboratory’s.
Storage area for plant supplies and consumables.
Reagents preparation facilities.
Security.
18.6Water
18.6.1Raw water

Raw water consists of fresh water that has not been used in the process and does not contain process reagents or salts. Raw water is consumed at an average rate as of 180 m3/h, while existing permits allow for up to 450 m3/h of consumption.

Raw water is drawn from the water collection dam and pumped to the lined raw water dam (also known as the ETA dam). The raw water flows from the ETA dam to the existing raw water treatment plant. Lime and aluminium sulphate is added to the raw water before it enters two primary water treatment filters. The raw water then flows to one of two locations, to either the plant raw water tanks for consumption in the plant, or for further treatment for use as potable water.

From the total 180 m3/h flow extracted at Igarapé William, which is primary filtrated and conditioned, 100 m3/h are directly used to refrigerate the milling equipment, part of this is evaporated and the balance is diverted back to the river. The balancing 80 m3/h flow, after primary treatment, is used at a rate as of 72 m3/h for washing and industrial purposes at the various installations (including the mine workshops) and as sealing water for the pumps at the plant, the remainder 8 m3/h are further treated to obtain potable water.

18.6.2Potable water

Raw water that is used for human consumption is transferred from the primary treatment filters to three filtered water tanks at an average rate as of 8 m3/h. This water is pumped to the potable water treatment plant, where is further filtrated and chlorinated to produce water of drinkable quality. The water is transferred from the potable water treatment plant into two potable water tanks. Two pumps (one duty, one standby) are used for distribution of potable water to end users.

18.6.3Process water

Process water consists of recycled and other waste streams used in the process, including return water from the TSF.

The plant consumes 550 m3/h of process water, being 100 m3/h used in the mill feed, 450 m3/h at the mill discharge and further 100 m3/h for the preparation of reagents.

Process water is stored and sourced from a dedicated process water dam. Water is pumped from the process water dam by four pumps (three duty, one standby) to the following users:

Grinding area water - mill trommel screens.
CIL area water - screen spray water and carbon transfer column eductor water.
Crushing area water - dust suppression sprays.

 

amcconsultants.com

209

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Overflow from the process water dam flows by gravity to the detoxification pond for cyanide destruction prior to discharge to the environment.

18.7Power

The Tucano mine power requirements are provided by two sources: 1) a 69 kilovolt (kV), 20 megavolt-ampere (MVA) power line via CEA and 2) a local supply authority, and a 12 MW continuous rated Aggreko diesel-powered generation system. The current demand is approximately 12 MW. At the completion of the additional ball mill and plant upgrade, now in progress, it is expected an increase of the demand to 15 MW.

The Aggreko generator facilities have a nominal capacity as of 12 MW, meeting the current demand, while the CEA line is being expanded to meet the total power requirements.

The CEA line capacity is currently limited to 20 MVA due to CEA distribution transformer limitations from 138 kV to 69 kV. A progressive strategy for the upgrade of the power line and transformers of the CEA line from 1.8 MW (prior to 2017) to 12 MW (already contracted) and, possibly, 15 MW (the final demand after the plant upgrade) has been implemented since 2017. The 70 km long 69 kV transmission line from the Coaracy Nunes facilities to the Mine has been continually upgraded and maintained and the capacity as of the first quarter of 2018 is 5 MW, resulting in significant increasing reliability of the system and substantial savings on diesel costs. A 30 MVA transformer from 138 kV to 69 kV to support the expansion of the capacity of the CEA line is in the late stages of procurement.

18.8Fire protection

There is a fire-fighting system next to the fuel storage and dispensing area and another one on the outdoor premises of the warehouse area. In both cases, the systems consisted of a tank and three fire pumps. A provision for additional local fire-fighting equipment near the oxygen plant location has been made.

18.9Communications

There are three rented interconnected private branch exchanges (PBXs). There are two Enterprise PCX services at the Tucano mine site with 300 extensions; one in the plant / administration area and the other at the residential camp. The third Enterprise PCX is at the Rio de Janeiro office and consists of one Embratel Link with 30 lines and up to 100 extensions.

There is a satellite communication internet link and two internet radio connections to Macapá.
At the Macapá office there is a fiber-optic link to Compuservice Webflash.
At Rio de Janeiro there are two redundant fiber-optic links.
There are 6 VPN site to site connections between the Rio de Janeiro office and the Tucano Mine, using the two Rio links and the three Tucano links.
There are 3 VPN site to site connections with the Macapá Office to Rio de Janeiro and the Tucano Mine.
Fiber-optic is available, with radio redundancy, between the mine areas, accommodation and industrial areas of the mine.
Network equipment based on Fast Ethernet and Giga Ethernet LAN and WIFI.

Light vehicles and mine equipment are equipped with mobile radios, and there are portable radios for operations personnel. There currently are 165 vehicle and equipment mounted radios, 206 hand portable radios, and 8 repeaters on the site.

 

amcconsultants.com

210

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.10Security

The main entrance security office is located at the Main Site access road. All visitors to the mine complex report to this security gate for authorization prior to entry. Additional fencing is provided for further safety and security within process plant areas, such as the gold room area, transformers and substations. A closed-circuit television system is installed in the plant and gold room to monitor activities.

18.11Personnel and personnel logistics

The mine currently employs a total of 680 staff on its books and 522 contractors.

The personnel living in Amapá accounts for approximately 65% of the workforce. Most of the workforce live in towns near the mine site with transport to Serra do Navio and Pedra Branca do Amapari provided by GPR in a daily basis. Personnel from Macapá also has transport provided by buses in a weekly basis. Most staff are Brazilian nationals, commuting to the mine. A few senior management staff and some expatriates working for contract companies MACA and McKay commute from overseas.

Managers and professional staff either commute from the state capital Macapá or from other cities in Brazil on a FIFO basis. Shift workers work a rotating 8 hr shift over a 24 hr period with a roster in days of 6 on 1 off, 6 on 2 off, 6 on 3 off basis. Managers and professional staff either work a roster in days of 19 on, 9 off or 5 on, 2 off. Expats work on a FIFO basis of 6 weeks on, 3 weeks off.

18.12Accommodation and medical care

There is an 85 person accommodation camp located to the east of the old leach pads, near the access road to the site. Senior staff uses the cabins in blocks of four in the upper part of the camp. Technical staff is accommodated in a longer barracks-style building downhill from the cabins. The rooms in the accommodation camp are air-conditioned and equipped with a refrigerator, writing desk, television, bed, bedside table and lamp, microwave oven, chair, en suite shower, toilet, and cupboards for clothing.

Communications for personnel purposes are provided at the lodging via telephone and wi-fi connections.

The camp also has a well-equipped gymnasium, games room, laundry, and restaurant area for ordering meals.

Medical facilities are close to the administrative offices and a medical doctor and nurses are permanently at the mine site to provide first care and treatment to GPR employees and contractors. There is provision for emergency removal of personnel either by ambulance, a mobile intensive care unit, and helicopter or plane, if needed.

18.13Tailings Storage Facility (TSF)
18.13.1Tailings operation

The Tucano Mine plant produces an average of 3.9 Mtpa of tailings (dry basis) from the gold beneficiation process; the tailings slurry is delivered to the TSFs via a fixed pipeline and is subaerially discharged into the various TSFs as a slurry at around 30% solids concentration (w/w). Tailings settle out in the TSFs to an average dry density of 1.2 t/m3, and supernatant water is removed from the pond via floating vertical pumps for recycle back into the plant circuit.

 

amcconsultants.com

211

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

A water balance of the LOM facility prepared by SRK (project BDR020 Water Balance Update) was used to determine spillway capacity, water reclaim availability, and storm management controls. The conclusions of this report indicated that on average, the plant water demand is met (no deficits in water availability) throughout the LOM. It is expected that the facilities will spill for post-closure conditions.

The LOM tailings production remaining, from May 2018 up to September 2025, is expected to be approximately 34.0 Mt, or a volume of 28.3 Mm3.

SRK has audited these facilities since commissioning of the TSFs, with a focus on safety and operational capacity of the embankments, pond size and ongoing construction of the facilities. The following audit site visits have been undertaken by SRK:

6 January 2014 - 7 January 2014: Mr Juan Moreno
16 November 2014 - 18 November 2014: Mr Juan Moreno and Mr. Nicholas Thompson
11 November 2015 - 16 November 2015: Mr Juan Moreno
19 October 2016 - 21 October 2016: Mr Juan Moreno
12 March 2017 - 15 March 2017: Mr Matheus Rocha
18 April 2018 - 21 April 2018: Mr Rubens Rocha.
18.13.2Description of the constructed TSFs

The Tucano TSF system consists of three facilities currently in operating conditions: Tap D, North Mill Pond (NMP) and West Pond Phase 1 (WPP1). A summary of the storage capacity of these facilities is provided in Table 18.1.

The remaining capacity of the current facilities is approximately 3.5 Mm3, which covers the storage for 12.0 months, or from October 2018 to October 2019.

GPR plans to extend the tailings storage capacity by commissioning two new TSFs, Barragem Leste and West Pond Phase 2 (WPP2).

Table 18.1 Summary of TSF storage capacity

Facility Tailings volume stored (m3) Remaining storage capacity (m3)
Tap D 6,200,000 Nil
NMP 3,328,000 2,200,000
WPP1 3,900,000 1,250,000
Total 13,428,00 3,450,000
18.13.2.1Tap D TSF

The Tap D TSF integrates three embankments and a small saddle wall that close a small valley just east of the process plant. The TSF includes two pits within its basin; namely Tap D1 and D2. SRK designed and supervised the construction of this facility.

The walls were named Wall 1, Wall 2, Wall 3, and Wall 4; these are shown in Figure 18.2. The design of these walls was provided in the Design Report (SRK projects BDR001 and BDR008). All the embankments are built with homogenous fills of low permeable material. The borrow material for the walls is a silty sand to sandy silt residual soil. A typical schematic cross section of these walls is shown in Figure 18.3.

 

amcconsultants.com

212

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.2 Tap D embankments

 

 

 

amcconsultants.com

213

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.3 Typical wall cross section

Active deposition in the Tap D TSF ceased in 2014 and it is since then dormant. The facility has not yet reached capacity and GPR has strategically opted to retain it as a contingency for emergency deposition, as it is located downstream of the mill. The Tap D TSF has received intermittent tailings discharge on a number of occasions, but it has been reported as minimal. The remaining capacity is not significant; however, some contingency is available since the current freeboard is significantly larger than the required (+3 m) and floating pumps are still operating in the basin.

18.13.2.2North Mill Pond TSF

The NMP TSF is a valley-type impoundment bounded by the West Pond Phase 1 (WPP1) TSF to the north and Tap D TSF to the south. The NMP facility was intended to act as a temporary measure while alternative facilities are commissioned in order to service the remaining LOM. SRK designed and provided partial supervision of the construction of this facility.

NMP TSF is composed of Wall 17 to RL 135 m with three additional minor compacted fill embankments (Walls 16, 18, and 19) required to be built to RL 135 m in saddles to enclose the site. A layout of the NMP site is presented in Figure 18.4.

 

 

amcconsultants.com

214

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.4 NMP embankments

 

 

 

amcconsultants.com

215

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.13.2.3WPP1 TSF

The WPP1 TSF integrates five walls that close a small valley approximately 1.5 km north east of the process plant. SRK designed and provided partial supervision of the construction of this facility.

The walls were named Wall 11, Wall 12, Wall 13, Wall 14, and Wall 15; these are shown in Figure 18.5, while the height of each wall is reported in Table 18.1. The design of these walls was provided in the Design Report for SRK project BDR005.

Figure 18.5 WPP1 embankments

 

 

 

amcconsultants.com

216

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The highest embankment is Wall 1, which is 33 m high, with the remaining walls being less than 15 m high.

All the embankments are designed as homogenous fills of low permeability material, with slope gradients at 2.5H:1V and 5 m wide crests. A downstream drainage and seepage collection system for long-term seepage control has been considered for Walls 11 and 12. A typical cross section for Wall 11 is presented in Figure 18.6 for reference.

Figure 18.6 Wall 11 cross section

18.13.2.4Integrated WPP1 and NMP TSFs

The WPP1 and NMP facilities were raised to integrate them into a single facility, the corresponding embankments crests were initially at RL 135 m and RL 130 m, respectively. These embankments were downstream, raised using a combination of rockfill and lateritic borrow material to RL 137 m, which allowed to raise the tailings level to a maximum elevation of RL 136 m. The spillway for the facility was relocated to Wall 16, as shown in Figure 18.7. The integrated facility was designed by SRK.

 

 

amcconsultants.com

217

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.7 Integrated WPP1 and NMP TSFs

  

18.13.3Extended tailings storage capacity

The current built TSF capacity is enough to store tailings up to October 2019. Additional tailings storage capacity is planned through commissioning two new facilities, Barragem Leste and WPP2, which would cover the tailings storage demand up to September 2025.

GPR is planning to first commission Barragem Leste, while working on the development of the larger WPP2 facility. Figure 18.8 presents the proposed TSFs.

 

 

amcconsultants.com

218

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.8 Proposed TSF expansion

 

 

 

amcconsultants.com

219

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.13.3.1Barragem Leste TSF

The Barragem Leste TSF is a valley-type impoundment bounded by the NMP TSF to the south; this facility will be constructed during the 2018 dry season (July to December) and will be commissioned in July 2019. The capacity of this facility is 4.9 Mm3, which would add 18 months of storage, up to December 2020. This facility has been designed by GeoHydroTech Engenharia to a conceptual level, and it is expected that the construction design will be ready in 2018.

The Barragem Leste TSF is composed of Walls 21 and 22 to a crest elevation of RL 137 m, these walls will be constructed as compacted low permeability homogeneous embankments. A typical cross section of the planned Walls is presented in Figure 18.9.

 

 

amcconsultants.com

220

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 18.9 Typical cross section of Walls 21 and 22a

 

 

 

amcconsultants.com

221

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

18.13.3.2WPP2 TSF

The West Pond (WP) TSF is a valley-type impoundment that was designed to be developed in two phases, WPP1 (approximately 35 ha) and WPP2 (approximately 167 ha), located to the east and west of the valley respectively. WPP1 has been constructed and is currently active. SRK has designed this facility to a detailed level.

In total, nine earth embankments (Wall 1 to Wall 9) were designed to isolate the WPP2 catchment and limit the spread of the tailings. A downstream drainage and seepage collection system for long-term seepage control was considered for Wall 1 to Wall 8. Wall 9 is a temporary structure that allows construction of WPP2 to be staged, if required. Figure 18.10 presents a layout of WP TSFs.

Figure 18.10 WP TSF layout

 

 

 

 

 

amcconsultants.com

222

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The storage capacity obtained after construction of the WPP2 is 23.7 Mm3, or 28.0 Mt. This TSF adds approximately 7 years of operational TSF capacity.

18.13.4Permitting of the TSFs

Operation of TSFs in Brazil requires a license to operate issued by the Instituto de Meio Ambiente and Regulacion Territorial, and a deforestation authorization (ASV) to implement the construction of the facilities.

The current operating TSFs have been granted license to operate (Liçença de Operaçao 0223/2015) from November 2015 to November 2021 (six years).

The integrated NMP and WPP1, has been permitted via Oficio 868/2017 by the Insitituto de Meio Ambiente and Regulacion Territorial, within the same operational license.

IMAP license and an ASV have been granted to permit construction of East pond (Barragem Leste). Construction of the East pond has begun.

Construction and operation of the WPP2 TSF requires a renewal of the current ASV. GPR has advised that the application for a new IMAP for this TSF is underway.

18.13.5Conclusions

There are three operating TSFs in the Tucano Mine, these are Tap D, NMP, and WPP1. The constructed storage capacity for tailings is 3.5 Mm3, which covers the storage for 15.7 months, or from October 2018 to October 2019. These facilities have been designed and audited by SRK since 2014 to date.

Further storage capacity is to be implemented by constructing two new TSFs, Barragem Leste and WPP2. These two facilities would provide 4.9 Mm3 and 23.7 Mm3 of tailings storage respectively, sufficient to cover the Tucano Mine LOM production to up to September 2025 at an average tailings production of 3.9 Mtpa.

18.14Underground infrastructure

Underground infrastructure is discussed in Section 16.5.

 

amcconsultants.com

223

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

19Market studies and contracts
19.1Markets

Gold output from the Tucano Mine operation is in the form of doré bars containing approximately 85% gold and 15% silver, the balance being copper and other minor metals. Silver credits are received from the refiner. The doré is shipped to Sao Paulo for refining. Umicore is the contract refiner and they retain Brinks to transport the bullion from Tucano to their facilities. Responsibility for the gold changes hands at the gold room gate. Based on actual contract agreements, the breakdown of costs is set out below:

Refinery charge US$3.86 oz gold (US$3.86/oz doré).
Transport, handling, and insurance US$ 17.50/oz gold.
Total US$ 21.4/oz gold.

The costs above are subject to some variation depending of the amount of ounces per shipment, however, they are representative of the average cost.

Penalties are applied in the refining contract for any impurities, but these are rare occurrences and the penalties are not excessive, the main impact being on the delay in final payment due to extended refining periods. The current refining contract is valid until the end of August 2019.

The market for gold doré is well established. Market predictions and discussions for gold are beyond the scope of this document. The impacts of gold price volatility on the mine plan and process operation are well understood.

19.2Contracts

As of 30 June 2017, the main contractors involved with the mine are:

Mining load and haul: U&M.
Mining Additional Equipment Support; JS Máquinas (excavators), Vale do Amazonas (excavators, haul trucks, dozers, ancilliary fleet), Masters (drilling), Norte Service (rock breaker).
RC Drilling: Geosedna.
Fuel supply: Ipiranga.
Power Generators: Aggreko.
Contract security staff: Prosegur.
Catering and camp management: JS Catering.
Offsite Laboratory: SGS GEOSOL,
Contract personnel transport: Vale do Amazonas & Palmerim.
Refining: Umicore.

The various contracts were awarded following a competitive bidding process, prices are within the industry range and comparable to other operations in Brazil.

 

 

amcconsultants.com

224

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

20Environmental studies, permitting, and social or community impact

In 2011 SRK Consultores do Brasil Ltda produced an Environmental Control Plan (PCA) to present changes implemented to the project’s environmental controls as a condition for the renewal of the Operating Licence issued by the State Secretariat of Environment, Amapá (SEMA). This followed a period of care and maintenance from 2009 until BDR acquired the project. The PCA reviewed changes to the process plant configuration (from heap leach to CIL) and ways of minimizing the environmental impact of the plant up-grade. The PCA also covered the environmental aspects of mining and plans to monitor and manage these as well as implementing various programs for the local community.

20.1Site visit

A site visit was conducted in March 2018 by Marcelo Batelochi the QP for Section 20. The site visit concentrated on the daily routine activities of the various operational sectors, concentrating on the monitoring of water quality as there is a creek crossing through the Project area (William Creek). In addition, the visit verified the monitoring requirements of Flora and Fauna, and the development of the native seedling nursery by BDR.

Air and noise monitoring comprises of mobile equipment that collects data in compliance with legal requirements and is performed by an independent company Análise Química Mineral, Ambiental e Industrial Mineral (ANQUIM). During the visit data collection was being carried out in the areas of the administrative offices, geology laboratory and carpentry workshop.

The monitoring of Fauna and Flora was not checked, but the activities of the field team, an independent company (MRW Ambiental), were observed.

With regard to community issues, a field trip with the community agents for BDR was performed from the land settlement lines southeast of the city of Pedra Branca do Amapari to the mechanized projects in the Nova Divisão community.

20.1.1Groundwater and surface water monitoring field check

Groundwater and Surface Water Monitoring is performed through field checking of daily monitoring activities and collection of samples for chemical analysis at the site facilities. There are also monthly, quarterly and half-yearly sample collections as required by environmental agencies, which are required to be sent to a certified external laboratory.

During the field visit, eight monitoring points were visited as shown the Google Earth map in Figure 20.1.

The first point was a solids containment dam at Urucum North pit. It was visually verified that the dam efficiently traps the solids upstream and clean and clarified water flows downstream. The remaining points visited represented piezometer monitoring at the pit, tailings dam, and industrial area in compliance with Environmental Plans approved by the governmental agencies.

The points visited for Surface Water Monitoring were selected downstream of the Taperebá project operations to check the quality of water that is returning to the environment after the interaction with the mining project. Visually, the water appeared to be of very good quality, with low turbidity and normal temperature, about 25°C.

 

amcconsultants.com

225

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 20.1 Location map of field visit monitoring points

20.1.2Socio-economics aspects field check

A field check of BDR’s socio-economic aspects was carried out by completing a visit to the town of Pedra Branca do Amapari municipality, where the community investments include popular Shopping infrastructure, and a Municipal Market. In addition, community investments in the form of the community roasted milled flour, and the result of the mechanization of the banana plantations were observed.

20.2Known environmental liabilities

The Project area is an active mining operation centred in dense tropical rain forest located in Amapá State, Brazil, consisting of open pit operations, crushing, milling and CIL processing that has a direct impact on the environment and the ecosystem of the region. The main impacts are on biological resources, air quality, noise and vibration, archaeology, hydrology (ground and surface water), and community stakeholders.

20.3Biological resources (Fauna and Flora)

The Tucano Project Flora is typical of an Amazon biome, identified as an area of Dense Ombrophylous Forest. The enormous biodiversity existing in this Amazonian ecosystem is favoured by the high structural complexity of the environment, with great vertical stratification, diversity of niches and microhabitats, providing a great number of species of Flora and Fauna.

The project area is not recognized as a priority for conservation, however, it should be noted that the mine is surrounded by areas of conservational interest. To the east and west is the State Forest of Amapá, at the northern limit is the National Forest of Amapá and to the southern extent is the Priority Area for Conservation of Biodiversity denominated Pedra Branca, that has a biological importance rating of Very High, due to the presence of certain sensitive areas in the ecosystem that include:

 

amcconsultants.com

226

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Preservation of species of economic importance.
Maintenance of animal species (spider monkey).
Wildlife Maintenance (MMA).
20.3.1Flora

The vegetation is very well conserved, with reduced stretches in regeneration that correspond to the areas of old gold panning sites. In the regional analysis of the project, a secondary vegetation strip is observed that corresponds to the headquarters of the municipalities of Serra do Navio and Pedra Branca do Amapari, which creates a geographic barrier to the flow of Fauna throughout the western flank of the mine.

The Flora Conservation Program is basically the case of germplasm collection in which the collector operates in areas under anthropic impact (Walter & Cavalcanti, 2005). In Legislative Decree No. 02 of 08/02/94, genetic resources are defined as ‘genetic material of real or potential value for human beings’, and ‘genetic material’ means all material of plant, animal or microbial origin, or other, containing functional units of heredity. Therefore, genetic resources represent a small share of biological resources, which in turn are components of biodiversity.

Based on these definitions, the Tucano Project has been involved with biodiversity conservation working primarily at the level of ecosystems and communities, while in the conservation of genetic resources, research is carried out at the level of species, that are populations and pools of a numerically very large universe of species.

The suppression of primary vegetation of Dense Ombrophylous Forest contributes to the reduction of the genetic variability of populations of the species occurring in the locality. This program uses the premise that the populations and or species affected by the anthropization contain genotypes not found in the remaining populations or elsewhere in their distribution areas, so that there will be loss of genetic variability (Walter & Cavalcanti, 2005). Even though this loss is small, it can be minimized by a detailed rehabilitation plan.

The salvage of the germplasm is based on information constructed with the data of the floristic and phytosociological inventory already carried out, and the evaluation of the biological value of the species, germplasm recovery and conservation of plant genetic resources. Rehabilitation is through the implementation of the re-vegetation sub-program on degraded areas or of future rehabilitation with planting or re-seeding, as well as the provision of genetic material for rehabilitation of the mine area.

20.3.2Fauna

The Fauna associated with the surroundings of the Tucano Project is rich and presents typical and endemic elements of Dense Ombrophilous Forest, as well as species of conservation interest such as Harpia, Myrmecophaga tridaetyla and Panthera onca.

The Fauna conservation program is based on the Normative Instruction (NI) 146/2007 of IBAMA (2007), that it is a guide instrument composed of procedures and regulations of field and laboratory activities, that undertake studies on the Fauna of regions under the influence of anthropization, providing accurate data to detect and quickly action to protect the environment.

 

amcconsultants.com

227

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The BDR Fauna monitoring program has provided to the stakeholders, governmental agencies and scientific community the composition and structure of Faunal communities occurring in the region of the Tucano Gold Project, and the means to evaluate these populations in relation to the future activities of the company.

In summary, the monitoring program consists of:

Logging the occurrence of species of mammals, amphibians, reptiles, birds, and fish on extended areas of the project influence.
Obtaining data on the composition, wealth, and abundance of communities.
Detection and evaluation of the interferences on faunistic communities.
Development and continuous improvement of controls and management to mitigate impacts on the Faunal communities.

 

This continuous Faunal monitoring has been carried out by an independent consultancy company (MRW Ambiental), which has been reporting the behaviour of the Fauna in the seasons of intense rains and drier periods, periodically, to the legislated governmental agency.

20.3.3Threatened and special status species

In order to reassess the conservation status of the Fauna described for the Tucano Gold Project, the list of endangered species contained in Article L. 411-1 of the Brazil Environmental Code (FR197/2010) strictly protects wild species of plants and animals listed by Ministerial Order. These species cannot be captured, transported, intentionally disturbed or commercially exploited. These prohibitions can extend to the destruction, degradation and alteration of the habitats of these protected species. A total of 110 nationally protected species were recorded on the Project site. Of these protected species, 100 were bird species, including three species with protected habitat, seven were mammalian species, and three plant species.

The site also hosts five new plant species and seven other plants of interest (rare or endemic), as well as two fish species rare and endemic, present in 1st / 2nd order creeks.

20.4Air quality

Control of air quality in the Brazilian territory is managed by Brazilian laws (CONAMA No. 08/90) establishing national emission limits for external combustion power up to 70 MW (seventy megawatts), Ordinance MINTER-100/80, which provides for the emission of smoke by diesel-powered vehicles, CONAMA No 01/90 and 03/90, ABNT / NBR 10151, CONAMA No. 436/2011 - NBR 9547, 12019, and NBR 12827. This set of regulations manage the emission control of gaseous effluents, airborne particulates, noise and vibration, effectively promoting the systematic monitoring of concentrations of pollutants to be discharged into the environment (atmosphere) and minimizing the degree of risk caused in the environment, keeping their concentrations below the legal limits. BDR periodically submit the monitoring reports to the governmental agency, as well as being regularly audited.

The air quality in the Tucano Project is measured on the gaseous effluents from the exhaust discharge of the generator sets of the Thermoelectric Plant (UTE), smoke indices from the diesel powered heavy equipment and through control of total suspended particles. These effluents have come from the UTE, processing plant, administrative area and explosives magazine.

The main air pollutants emitted by the UTE are nitrogen oxides composed of nitric oxide (NO), nitrogen dioxide (NO2) and carbon dioxide (CO2). In smaller amounts, carbon monoxide (CO), hydrocarbons, smoke, and sulphur dioxide (SO2) are also expelled.

 

amcconsultants.com

228

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

In a sample analysis of reports submitted to government agencies, the concentrations of NO, NO2, CO, CO2, O2, and SO2 show satisfactory indices below the reference limits of the equipment. Suspended total particle concentrations, have higher concentration indices for periods of low rainfall but are well below the acceptable maximum limit.

Smoke ratings on off-road mobile equipment and light vehicles have satisfactory rates of 20% or less (RINGELMANN comparative scale No.1).

20.5Noise quality and vibrations

The main noise and vibration are related to the haulage vehicles, blasting and heavy equipment - fixed and mobile:

Vibrations and noise caused by traffic and use of heavy equipment are relatively minor and can be considered negligible.
The crushing system and beneficiation plant generates high noise / vibration levels that have been monitored in order to ensure that maximum levels acceptable within the legal limits are not exceeded. Several items of equipment have enclosed, or acoustic barriers installed in order to guarantee the noise levels remain below the limits of the legislation. In addition, periodic and corrective maintenance is done to keep noise within the limits set by manufacturers and specific legislation.
Blasting has been limited to a scheduled specific time and these blasting schedules must be pre-defined and marked on visible notices at the entrance to the mine areas. The Project does not have communities in its immediate surroundings and the noise and vibration of blasting is negligible to neighbourhood communities.

Noise routinely monitored in these areas shows levels below 70 dBA. On site, the compulsory use of individual hearing protection is enforced.

20.6Geotechnical

The geotechnical control and monitoring implemented at the Project consists of designing a set of sediment retention structures and slopes in the pit and the surrounding hills inside the Project area. The slopes are controlled by the Mine Planning and Mine Operation departments with specific controls developed by specialists in geotechnical engineering and monitoring of soil / rock potential displacement points. The sediments are controlled by collecting water run-off and directing it through surface drainage systems and internal drainage systems (in the case of waste and pits), thus allowing reduction or even elimination, of the solid material suspended in the water that is carried to existing waterways, primarily William Creek.

The main objective of these geotechnical controls is to ensure efficient prevention of erosion and prevent solids in the form of sediments flowing into the waterways and the environment and, consequently to minimize the impact on the surrounding non-anthropized areas.

20.7Hydrogeology (groundwater), hydrology (surface water)

The hydrogeology and hydrology are critically related to the equatorial regions, where rainfall levels exceed 2,000 mm per year, and it is the most relevant element of the physical environment that impacts on the ecosystem. For this reason, the characterization and constant monitoring of groundwater, surface water and rainwater is essential to minimize the impact of the Tucano operations.

The Project implemented monitoring of the hydro system, since 1999, where surface sampling points and piezometers were geo-referenced and flagged. The routine sampling has been collecting quality base data (CONAMA 20/86 standard), with which current water quality sampling is compared (CONAMA 357/05). Sampling includes physical parameters of acidity, conductivity, temperature, dissolved oxygen, and turbidity. Samples are sent for laboratory analysis for metal content (anions and solids levels).

 

amcconsultants.com

229

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

In 2005, before starting operations, this monitoring system was extended to cover the area considered under the feasibility study including the waste dump, tailings, industrial plant, and buildings.

Currently, the underground and surface water-monitoring system is composed of 57 points. Due to adjustments on the Project infrastructure due to the dynamics of the operation, several piezometers and water surface points were unused, and others were installed in the area of coverage.

The results of monitoring and evaluation have been systematically submitted to the environmental agencies (SEMA / IMAP) as official Brazilian governmental reports that become public information for mitigation and minimization of the impacts of the dynamic local hydro system, as a result of the mine operation.

20.8Cultural and archaeological resources

The archaeological site studies in the Brazilian territory are conditioned by the articles 20, 23, 215, and 216 of the Federal Constitution; Laws No 3.924, 26 July 1961; Ordinance SPHAN No 07, 10 December 1988; Ordinance IPHAN No 230, 17 December 2002; Normative Instruction IPHAN, No 001, 25 March 2015. In which the archaeological studies carried out by BDR at the Tucano Project fully complied with the Brazilian regulations.

20.8.1Regional archaeological context

The State of Amapá has known archaeological evidences dating back to the sixteenth century, from scientific expeditions by naturalists, travellers, and ethnologists, among which is the stand out contribution from Crevaux, Coudreau, P Curt Nimuendajú, and Emilio Goeldi on the archaeological ceramics.

In the Tucano Project area, municipalities of Pedra Branca do Amapari, Serra do Navio, and Porto Grande there are 68 identified archaeological sites, most of them associated with historical and pre-colonial sites.

20.8.2Archaeological studies at Tucano Project

Archaeological research was initiated in 2005 by Nunes Filho (2007 & 2009), when the project belonged to Wheaton River Minerals, and carried out in accordance with the Archaeological Program defined in the Environmental Impact Study, approved by SEMA (state environmental agency).

2006 and 2007, carried out several surveying, prospecting (with sample collection of artefacts), elaboration of surface diagnostics (for preliminary cultural characterization of each archaeological site), archaeological excavation and laboratory study, with the main objective of training a local team in archaeology and Patrimonial Education.

All the archaeological material collected during the activities was duly packed and transported to the Archaeological Laboratory of the Archaeological Studies and Research Center of Amapá - Cepap (Unifap), where they went through the processes of cleaning, cataloguing, analysis, and restoration.

The result of the archaeological studies during 2006 and 2007 identified 11 archaeological sites, all of them prehistoric, among which three were excavated and studied. In 2008, the archaeological survey identified seven archaeological sites, all of them prehistoric, these were excavated and studied, and the material, as in previous years, was duly sent to Unifap. Also, in 2008, five carbon samples were sent to the Beta laboratory in the United States for carbon dating. In 2009, in the municipality of Pedra Branca do Amaparí, four other archaeological sites were rescued, with the excavation of three sites and surface collection of one site. Currently, this area belongs to Zamin Resources Ltd. The results of the archaeological studies from 2005 to 2009 subsidized the BDR Operation Licensing for current operation at Tucano Project.

 

amcconsultants.com

230

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

After 2012, when operations commenced, archaeological studies were part of the routine management of the company, working together with near mining mineral exploration, monitoring, mapping / identifying sites and restoring artefacts.

20.9Socio-economics

The Tucano Project covers an area of approximately 4,000 km2 socially affected by the mining project, partially including the municipalities of Serra do Navio and Pedra Branca do Amapari, in which the population is distributed at the town and in small communities.

The municipality of Pedra Branca do Amapari, has a population of 10,773 inhabitants with a population density of 0.50 habitants/km². The entire population is considered a stakeholder of the project within the scope activities, totalling 21 communities dispersed along the unpaved highway BR-210.

The municipality of Serra do Navio, has a population of 5,111 inhabitants with a population density of 0.66 habitants/km², where practically the entire population is included within the Property, acting both in the town and the 10 small communities surrounding the western part of the Tucano project.

BDR has two professionals working full time closely with the communities. Among the actions already developed since the beginning of its activities are:

Community Development Funds, with the distribution of resources through the approval of specific projects submitted in partnership with the Community Councils of Pedra Branca do Amaparí and Serra do Navio.
Job creation and increasing earnings, with the prioritization of labour and local suppliers, as well as several projects with direct participation of stakeholders, which include:
Projects of fisheries (fish farms).
Co-operative of seamstresses "Rosa Branca do Amaparí.
Donation of truck to farmers.
Libraries.
Training courses for environmental and community agents.
Juniors Entrepreneurship Education Project.
Cooking project “Cozinha Brasil”.
Implementation of computer laboratory.
Community factories of roasted cassava flour.
Paper recycling workshops in Pedra Branca do Amaparí and Serra do Navio.
Project “Guarda Mirim” with support of uniforms and donation of musical instruments.
Educational games and “Gol de Placa” Project.
Elaboration of educational folders.
Donation of school supplies.
Social assistance with:
Donation of fuel and support for the Tutelary Council of municipalities and school busses.
Basic food baskets distribution.

 

amcconsultants.com

231

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Circle of lectures and solidarity aid related to commemorative dates, such as Solidarity Christmas, New Year’s Day (Ano Novo da Paz), International Women's Day, and Easter, among others.
Constant visits to communities working solidarity within the community routines.
Health, where the company donated two ambulances, one for each Municipality Health Department.
Public Security, where the company donated vehicles to the Environmental Battalion of the Military Police of Amapá State.
Infrastructure
Constant support for repairs and improvement of access roads.
Support to the improvement of sanitation infrastructure, public buildings, and streets.
Donation of diesel fuel oil to the municipality solid waste collection service.
Infrastructure for popular shopping.

 

 

 

amcconsultants.com

232

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

21Capital and operating costs
21.1Capital expenditures

Total capital expenditures for 2018 have been estimated at US$26.9M, inclusive of US$18.5M for the completion of the Tucano Plant Expansion Project. Other significant estimated capital expenditures calculated at an exchange rate of 3.3 in 2018 are:

Tails storage facility - 2018; US$2.68M.
Powerline upgrade - 2018; US$1.52M.
Urucum site buildings - 2018; US$1.10M.

This does not include capitalized stripping or miscellaneous minor capital requirements.

21.2Operating costs

The 2017 operating costs for the Tucano mine are presented in Table 21.1 and include all mining, treatment, and general and administrative costs, which were incurred at the mine site. The cash operating costs exclude depreciation, amortization, sustaining capital, and corporate general and administration costs.

Table 21.1 Cash operating costs 2017

Year 2017 Cost (US$M) Unit cost  
Item
Operational mining costs 96.68 4.10 US$/tonne mined
Operational processing costs 54.62 14.68 US$/tonne milled
On-site general & administrative costs 7.65 2.06 US$/tonne milled
Inventory adjustments and other costs -17.85    
Total 141.09 1,100 US$/ounce sold

Note: The operating costs for 2017 were US$1,100/oz of gold sold using a US$/R$ exchange rate of 3.193. In 2017, the mine produced 129,764 oz at an all-in sustaining cost (AISC) of US$1,180/oz.

21.2.1Underground capital costs - basis of estimate

Capital costs have been estimated based on the following:

Capital infrastructure - is based on preliminary design assumptions and costing undertaken for other projects during the past 5 years. Where possible labour rates in these estimates have been adjusted to reflect Brazilian labour rates. A contingency of 20% has been added to these costs to cover the fact that detailed engineering has not been undertaken for these items and for minor items not yet allowed for in the PFS.
Capital lateral and vertical development - based on mining schedules and first principles estimates based on equipment operating costs and assumptions and employee cost assumptions. A raiseboring cost of US$5,000 per metre has been assumed for 3.6 m diameter raises connecting to surface.

All costs, unless otherwise stated, are in US dollars ($).

21.2.2Contractor mining versus owner mining

By deploying a mining contractor and not having to purchase the mobile equipment fleet upfront, AMC estimates that some capital cost savings could be realized. Project capital costs could reduce further depending on the mobile equipment and infrastructure the contractor may already have, and how it has been depreciated in the past.

 

amcconsultants.com

233

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

In view of the above, AMC has based this capital cost estimate on deploying an experienced mining contractor to develop and operate the project and assumes:

The contractor would lease the underground mobile equipment fleet and pass on the leasing costs to GPR, together with all mining costs plus a contractor margin of 10%.
GPR would finance all underground and surface infrastructure for the project.
GPR would be responsible for all power and diesel costs.
21.2.3Total underground capital cost estimate

The total underground capital cost estimated for the project over the LOM is summarized in Table 21.2. The estimated capital cost by year is shown in Table 21.3.

Table 21.2 Pre-production capital considers all capital expenditure in Year 1 (2019).

Table 21.2 Pre-production capital and total capital cost estimate

  Pre-production capital ($)
Item Total ($) Y01
Jumbo development 19,556,460 1,992,446
Underground infrastructure 11,027,907 1,700,966
Surface infrastructure 7,259,353 3,665,152
Raiseboring 2,079,585 1,097,021
Infrastructure contingency 4,073,369 1,292,628
Total capital 43,996,674 9,748,213
Pre-production capital 9,748,213  
Sustaining capital 34,248,461  
Total LOM Capital 43,996,674  

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

 

 

 

amcconsultants.com

234

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 21.3 Capital cost estimate by year

Capex item Total 2019 2020 2021 2022 2023 2024 2025 2026
Jumbo development 19.56 1.99 6.33 6.27 4.27 0.35 0.34    
Underground infrastructure                  
Egress ladderway 0.56 - 0.17 0.22 0.11 0.02 0.04    
High / medium voltage switchgear 0.47 0.47              
Power supply and distribution 4.47 0.39 1.46 1.48 0.98 0.09 0.07    
Mine dewatering and water supply 4.10 0.36 1.34 1.36 0.90 0.08 0.06    
Compressed air - portable compressors 0.20 0.10 0.10            
Refuge chambers 0.22 0.11 0.11            
Fire detection and suppression 0.16 0.08 0.08            
Leaky feeder communications system 0.17 0.01 0.05 0.05 0.04 0.00 0.00    
Mine rescue equipment 0.10 0.05 0.05            
Auxiliary ventilation fans and regulators 0.40 0.03 0.13 0.13 0.09 0.01 0.01    
UG workshops - underground fitout 0.20 0.10 0.10            
Surface infrastructure                  
Portal preparation 0.20 0.20              
Surface exhaust fan (2 x 560 kW parallel fans) 2.63 1.31 1.31            
Change rooms / lamp room / lamps + SRs 1.47 0.18 0.18 0.18 0.18 0.18 0.18 0.18 0.18
Underground mining offices 1.13 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
Surface workshop 0.30 0.30              
Water supply (PRV, tanks) 0.24 0.24              
Explosives magazine - -              
Fuel storage and bowser 0.15 0.15              
Stores / warehouse facility - -              
Surveying and engineering equipment 0.20 0.20              
First fills 0.94 0.94              
Raiseboring 2.08 1.10 0.98            
Infrastructure contingency 4.07 1.29 1.24 0.71 0.49 0.10 0.10 0.07 0.07
Total Capex 44.00 9.75 13.80 10.55 7.20 0.98 0.95 0.39 0.39

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

The projected annual capital expenditure is summarized in Table 21.4.

Table 21.4 Annual capital expenditure

Year Date Capital $M
Year 1 2019 9.75
Year 2 2020 13.80
Year 3 2021 10.55
Year 4 2022 7.20
Year 5 2023 0.98
Year 6 2024 0.95
Year 7 2025 0.39
Year 8 2026 0.39
Total   44.00

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

 

amcconsultants.com

235

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

21.2.4Underground lateral development capital costs

Capital lateral development is expected to cost approximately US$20M over the life of the project. This cost excludes material handling costs, power, and diesel costs which have been allocated to operating costs.

21.2.5Underground vertical development capital costs

Capital raiseboring is expected to cost around US$2M during the first 18 months of the project. Additional long-hole raising for both the airway extensions and emergency egress has been costed as an operating cost (apart from purchasing of the emergency ladderway at a cost of $0.5M).

21.2.6Underground mobile equipment capital costs

The underground mine is assumed to use a contractor for all development and production throughout the life of the mine. The equipment costs are included in the contractor’s development and production mining rates.

The estimate for the contractor provided equipment includes the following (based on maximum requirements):

Longhole production drill (1)
Jumbos - double-boom (6)
10-tonne LHDs (5)
Articulated trucks - 32.5-tonne (5)
Cable bolters and shotcrete machines (4)
Ancillary equipment
21.2.7Underground infrastructure capital costs

The underground infrastructure capital cost estimate is $11M (Table 21.5). Costs are based upon supplier quotations and unit rates from past experience with similar projects. The underground infrastructure costs largely consist of electrical reticulation, ventilation and dewatering system costs.

Table 21.5 Underground infrastructure capital costs

Description $M
Egress ladderway 0.56
High / medium voltage switchgear 0.47
Power supply and distribution 4.47
Mine dewatering and water supply 4.10
Compressed air - portable compressors 0.20
Refuge chambers 0.22
Fire detection and suppression 0.16
Leaky feeder communications system 0.17
Mine rescue equipment 0.10
Auxiliary ventilation fans and regulators 0.40
UG workshops - underground fitout 0.20
Total 11.03

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments

 

amcconsultants.com

236

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

21.2.8Surface infrastructure capital costs

Table 21.6 shows a breakdown of the direct capital costs estimated for the surface infrastructure required to support underground mining.

Table 21.6 Surface infrastructure capital costs

Description Total $M
Portal preparation 0.20
Surface exhaust fan (2 x 560 kW parallel fans) 2.63
Change rooms / lamp room / lamps + SRs1 1.47
Underground mining offices 1.13
Surface workshop 0.30
Water supply (PRV2, tanks) 0.24
Explosives magazine* -
Fuel storage and bowser 0.15
Stores / warehouse facility* -
Surveying and engineering equipment 0.20
First fills 0.94
Total 7.26

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

(1) Self-rescuers.

(2) Pressure reducing valve.

* The underground mine will use existing facilities that support the open pit mine.

21.2.9Exclusions from the underground cost estimate

The following costs have not been included in the underground capital cost estimate:

Mine closure costs (to be captured as part of open pit costs).
Mill modification costs.
Surface road costs to the Urucum North Underground Mine site.
Additional explosives magazine facilities.
Additional stores / warehousing facilities.

AMC understands that existing facilities can be used in terms of the surface road, explosives magazine and stores / warehouse.

21.2.10Indirect capital costs

Indirect costs are those relating to engineering, procurement, and construction management (EPCM), the costs associated with servicing and maintaining the mine during the construction period, and operating costs incurred prior to first concentrate production. No owners’ costs or EPCM have been considered in the cost estimate.

21.2.11Capital contingency

Capital contingency total amounts are shown in Table 21.6 and average approximately 10% of the direct capital cost.

 

amcconsultants.com

237

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 21.7 Capital contingency

Contingency $M
Mine infrastructure 2.2
Surface infrastructure 1.5
Raiseboring 0.4
Total 4.1

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

21.2.12Underground operating costs - basis of estimate

Underground operating cost estimates have been built up from first principles based on the following:

AMC benchmarked mining equipment operating costs and productivities.
Budget quotations for the mining fleet.
The mining schedule - output from Mine24D and EPS schedules.
Underground mining productivities for the various equipment types.
Employee costs based on operating and maintenance assumptions and the employee costs.
Effective working hours per shift for the underground workforce are 5 hrs 45 mins per shift.
Power costs for pumping and ventilation are based on calculated power consumption (by year) and a power cost of US$0.08 per kWh (based on connecting to grid power in the future).
Diesel cost of US$0.80/l.
Diamond drilling based on a contractor rate of US$120/m (includes assaying, etc.).
A mining contractor margin of 10%.
An operating cost contingency of 10%.
R$/US$ exchange rate of 3.8:1.
Infrastructure costs (power water etc.) based on recently completed projects outside of Brazil but with the labour component adjusted to reflect Brazilian labour costs.
Surface ore transport cost of US$1.35/t (based on scoping study estimate).
A cost of US$17/t has been included to cover ore processing and G&A. (based on scoping study estimate).

It is assumed that the mining contractor will lease the mobile equipment fleet and charge the leasing costs back to GPR as an operating cost. The equipment leasing costs are estimated to total US$29M over the life of the project.

21.2.13Underground mine total operating costs

LOM underground total operating costs, by major area, are shown in Table 21.8; annual operation totals are shown in Table 21.9.

Table 21.8 LOM underground total operating costs by major area

Department $M
Mine 170.4
Process plant and G&A 40.4
Total 210.9

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

 

amcconsultants.com

238

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 21.9 LOM underground total operating costs by year

Year Date Operating cost $M
Year 1 2019 8.3
Year 2 2020 26.9
Year 3 2021 36.0
Year 4 2022 39.4
Year 5 2023 28.2
Year 6 2024 29.6
Year 7 2025 22.7
Year 8 2026 19.7
Total   210.9

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

LOM average underground total operating costs have been estimated at $88.67/t milled. The cost breakdown by major area is shown in Table 21.10.

Table 21.10 LOM average underground total operating costs

Area $/t milled
Mine 71.67
Process plant and G&A 17.00
Total 88.67

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

21.2.13.1Underground mining cost

Underground mining cost estimates are detailed in Table 21.11.

Table 21.11 Underground mining costs

Operating costs $M $/t milled
Lateral development 17.7 7.45
Stoping 5.3 2.24
Materials handling 31.3 13.17
Power 12.4 5.20
Diesel 7.6 3.20
Ancillary equipment 3.3 1.38
Management and supervision 33.5 14.10
Miscellaneous 3.5 1.46
Surface haulage HG Ore 3.9 1.64
Mining opex cost contingency 11.9 5.00
Mining contractor equipment leasing costs 29.0 12.21
Mining contractor margin 11.0 4.61
Total 170.4 71.67

Note: Totals may not necessarily equal the sum of the components due to rounding adjustments.

 

amcconsultants.com

239

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

21.2.14Underground mobile equipment assumptions and costs

Underground mobile equipment requirements are based on the productivities indicated in Table 21.12.

Table 21.12 Underground mobile equipment productivity assumptions

Equipment Instantaneous productivity Availability % Utilization%
Jumbo - double boom 84.3 drill m/hr 70 30
Scaler 6.0 dev m/hr 70 30
Rock bolter 14.5 bolts/hr 70 40
Production drill 34.8 drill m/hr 80 25
LHD (10 tonne) 91.0 t/hr 80 50
Front-end loader (UG truck loading) 300.0 t/hr 80 50
Articulated truck 200.0 t-km/hr 80 60

Underground mobile equipment operating costs are based on the operating labour, consumables and energy costs indicated in Table 21.13.

Table 21.13 Mobile equipment operating cost assumptions

Equipment type Unit Operating labour (hr/unit) Consumables ($/unit) Energy ($/unit)
Jumbo - double boom drill m 0.04 1.89 0.14
Scaler dev m 0.56 40.00 40.00
Rock bolter bolts 0.35 48.00 8.00
Production drill drill m 0.11 7.12 0.21
LHD (10 tonne) t 0.02 0.20 0.34
Front-end loader (UG truck loading) t 0.01 0.20 0.34
Articulated truck t-km 0.01 0.08 0.27

Underground mobile equipment maintenance costs are based on the maintenance labour, consumables and energy costs indicated in Table 21.14.

Table 21.14 Mobile equipment maintenance cost assumptions

Equipment type  Unit Maintenance labour (hr/unit) Consumables ($/unit) Energy ($/unit)
Jumbo - double boom drill m 0.03 3.49 0.08
Scaler dev m 0.30 1.20 40.00
Rock bolter bolts 0.20 1.20 8.00
Production drill drill m 0.04 10.63 0.09
LHD (10 tonne) t 0.01 1.30 0.08
Front-end loader (UG truck loading) t 0.01 0.70 0.08
Articulated truck t-km 0.01 0.41 0.01
21.2.15Employee costs / labour costs

Employee costs have been based on annual wages as indicated in Table 21.15. These wages have been sourced from Brazilian 2014 wages quoted in R$/month adding 10% for inflation then converted to US$ rates using an exchange rate of US$:R$ of 1:3.8. These wages are inclusive of Brazilian labour benefits indicated in Table 21.16.

 

amcconsultants.com

240

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 21.15 Employee wages

Type 2014 wage (R$ / month) Wage (US$ / year)
Jumbo operator 7,822 27,171
Production drill operator 7,822 27,171
LHD / Truck operator 7,822 27,171
Semi-skilled labourer 6,509 22,611
IT operator 6,509 22,611
Unskilled labourer 5,393 18,732
Explosives charger operator 7,822 27,171
Mining supervisor 17,799 61,828
Technician 12,888 44,768
Maintenance engineer 28,953 100,574
Supervisor 17,799 61,828
Planner / Programmer 9,248 32,124
Artisans 7,822 27,171
Electricians 9,248 32,124
Geotechnical engineer 39,292 136,490
Engineer 39,292 136,490

Table 21.16 Employee benefits

Benefits Value Unit
Medical and dental cover cost 400 R$ per month
Profit share 2 % of Wage
Travel allowance 500 R$ per month
Meal cost 20 R$ per month
Meal and lunch ticket 20 R$ per month
Medical checks 85 R$ per month
Other personal expenses 150 R$ per month
Life insurance 170 R$ per month
13th salary provision 170 R$ per month
Benefit for dangerous work 30 % of Wage
Benefit for extended shift 25 % of Wage
Benefit for health-risk work 20 % of Wage
Benefit for night shift 10 % of Wage
Annual leave provision 8 % of Wage
FGTS 170 R$ per month
INSS 170 R$ per month

 

 

 

 

amcconsultants.com

241

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

22Economic analysis

GPR is a producing issuer, as defined by NI 43-101 and is currently in production.

The economics regarding only the proposed underground mine are discussed further.

22.1Underground mine economics
22.1.1Assumptions

All currency is in US dollars ($) unless otherwise stated. The cost estimate and projected revenue for the underground mine were prepared with a base date of Year 1 and use constant Year 1 dollars (no inflation). For NPV estimation, all costs and revenues are discounted at 5% from the base date. The gold price was selected after discussion with GPR and referencing current market and recent historical prices, values used in other recent projects, and forecasts in the public domain. No depreciation, amortization or taxation has been undertaken in this evaluation. An exchange rate of US$:R$ of 1:3.8 and a royalty of 2% have been assumed. Changes to the exchange rate affect labour costs only.

Revenues from gold production have been based on:

Metallurgical recovery of 90% (based on various metallurgical studies of the Tucano ore supported by actual recovery data from current mining and processing of the Urucum open pit ore).
Gold price of $1,200/oz in line with recent assumptions by GPR for Mineral Reserve estimates.
Gold royalty of 2%.
22.1.2Economic analysis

AMC has conducted a pre-tax economic assessment of the Urucum North Underground Mine. Over an 8-year operating life, the mine is projected to generate approximately $25.5M pre-tax NPV at 5% discount rate, with a pre-tax internal rate of return (IRR) of 19.9%.

Project capital is estimated at $44M with a payback period of 4.9 years (undiscounted pre-tax cash flow from Project Year 1). Key assumptions and results of the underground mine economic assessment are provided in Table 22.1. The LOM production schedule, average gold grade, recovered metal, and cash flow forecast are shown in Table 22.2.

An operating cash cost of $802.37 per oz of gold over the LOM was calculated by taking the total operating costs (excluding Year 1) and dividing this value by the payable ounces of gold (excluding Year 1).

 

amcconsultants.com

242

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Table 22.1 Key economic assumptions and results for the underground mine

Urucum North Underground project Unit Value
Total ore production kt 2,378
Total waste production kt 2,000
Gold grade (average)1 g/t 3.6
Overall gold recovery (mill) 1 % 90
Gold price $/oz 1,200
Payable gold metal oz 252,801
Gross revenue $M 303
Royalty % 2.0
Capital costs - pre-production $M 10
Capital costs - sustaining $M 34
Mine operating costs2 $M 170
Mine operating costs2 $/t ore 71.67
Operating costs (total)3 $/t ore 88.67
Cash cost4 $/oz Au 802.37
Undiscounted cashflow (pre-tax) $M 42.4
Pre-tax IRR % 19.9
Discount rate % 5
Pre-tax NPV5% $M 25.5

Notes: Totals do not necessarily equal the sum of the components due to rounding adjustments.

(1) LOM average.

(2) Underground mining costs only.

(3) Includes mine operating costs, milling, and G&A.

(4) Excludes off-site costs such as smelter treatment, refining, and transportation costs.

 

 

amcconsultants.com

243

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 22.2 Urucum North Underground LOM production and cash flow forecast

Item Unit Total 2019 2020 2021 2022 2023 2024 2025 2026
Ore mined t 2,378,113 4,861 217,801 341,481 464,935 419,166 352,862 303,141 273,865
Development - lateral m 35,995 2,159 8,409 9,886 8,119 2,259 3,277 1,084 801
Development - vertical m 2,270 250 698 729 374 85 133    
Waste mined t 1,999,824 159,539 559,767 613,523 432,137 90,311 95,885 32,937 15,724
Gold grade - milled g/t 3.64 2.8 3.0 3.4 4.1 4.0 3.8 3.7 3.1
Overall gold recovery % 90 90 90 90 90 90 90 90 90
Gold payable metal oz 252,801 390 18,820 33,454 55,602 48,619 39,104 32,270 24,544
Total net revenue1 $M 297.3 0.5 22.1 39.3 65.4 57.2 46.0 37.9 28.9
Operating costs                    
Underground mining $M 170.4 8.3 23.2 30.2 31.5 21.1 23.6 17.6 15.0
Processing and G&A $M 40.4 0.1 3.7 5.8 7.9 7.1 6.0 5.2 4.7
Total operating cost $M 210.9 8.3 26.9 36.0 39.4 28.2 29.6 22.7 19.7
Capital costs                    
Project capital $M 9.8 9.8              
Sustaining capital $M 34.3   13.8 10.6 7.2 1.0 1.0 0.4 0.4
Total capital cost $M 44.0 9.8 13.8 10.6 7.2 1.0 1.0 0.4 0.4
Undiscounted cash flow (pre-tax) $M 42.4 (17.6) (18.6) (7.2) 18.7 28.0 15.4 14.8 8.8
Discounted cash flow (pre-tax)5% $M 25.5 (16.8) (16.9) (6.2) 15.4 22.0 11.5 10.5 6.0
Cumulative pre-tax NPV5% $M 25.5 (16.8) (33.7) (39.9) (24.5) (2.5) 9.0 19.6 25.5

Notes: Totals may not necessarily equal the sum of the components due to rounding adjustments.

(1) Gross revenue less any selling, refining, transportation, and royalty costs.

 

 

amcconsultants.com

244

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Production costs, revenues, and cumulative pre-tax cash flow by year are shown in Figure 22.1.

Figure 22.1 Production costs, revenues, and cumulative pre-tax cash flow by year

Source: AMC

22.2Taxes and Royalties

There are two corporate income taxes in Brazil which GPR is subject to: (a) the Corporate Income Tax (IRPJ) and (b) the Social Contribution Tax on Profits (CSLL). The tax base of IRPJ and CSLL is similar, although some specific adjustments may be applicable to one tax and not to the other.

As GPR will operate in the Amazon region of Brazil, the company is eligible for certain tax incentives.

IRPJ is a federal tax charged on net taxable income. It applies at a basic rate of 15%, plus a surtax of 10% on annual income that exceeds R$240,000 per year.

CSLL was introduced to fund social and welfare programs and is paid in addition to IRPJ. CSLL is also a federal tax levied on net taxable income and is applied at a rate of 9%.

Tax losses may be carried forward indefinitely. The offset is limited to a maximum 30% of annual taxable income. Tax losses may be lost if, between their generation and utilization, there is a change in control and change in the business activity performed by the taxpayer.

The Tucano Gold Mine is located in the state of Amapá in the Amazon region of Brazil, and as such the operation is eligible for, and has received, certain incentives under the Superintendence of Amazonas Development (SUDAM) regime.

SUDAM oversees development in the Amazon region and is administered by the Brazilian federal government. Under the SUDAM regime, the Company has received a 75% tax exemption on IRPJ payable on net taxable income generated from the Tucano Gold Mine. The SUDAM benefit applies for a 10 year period and commenced in 2013 in relation to the Tucano Gold Mine.

 

amcconsultants.com

245

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Royalties are discussed in Section 4.4.

22.3Economic sensitivity analysis

AMC has carried out a sensitivity analysis of the projection for Urucum North Underground economics. The sensitivity analysis examined the impact on pre-tax NPV (at 5% discount rate) of a 20% positive or negative change in the gold price, total production cost (all operating and capital costs), foreign exchange rate (US$:R$) and the price of power.

The results of the sensitivity analysis are shown in Table 22.3, Figure 22.2, and in Figure 22.3.

The results show that the pre-tax NPV is positive and remains so for the range of sensitivities evaluated for exchange rate and the cost of power. For the sensitivity of the gold price, the pre-tax NPV is positive when the price of gold is over $1,070/oz and for the total operating cost, the pre-tax NPV is positive when the total operating cost does not increase by more than 15%.

Pre-tax NPV is most sensitive to changes in the gold price and to changes in the total operating cost. The NPV is moderately sensitive to changes in the exchange rate. Changes in the cost of power have the least impact on NPV.

 

 

 

amcconsultants.com

246

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 22.3 Economic sensitivity analysis (pre-tax)

Item Value Unit Pre-tax NPV ($M) Pre-tax IRR %
Base case (NPV at 5%)     25.5 19.9
Gold price - fall of 20% 960 $/oz (22.3) (9.4)
Gold price - increase of 20% 1,440 $/oz 72.3 44.6
Total operating cost - fall of 20% 168 $M 59.4 41.2
Total operating cost - increase of 20% 253 $M (8.4) 0.1
Total power cost - fall of 20% 10 $M 29.0 21.9
Total power cost - increase of 20% 15 $M 21.4 17.5
Exchange rate - fall of 20% 3.0 US$:R$ 13.2 12.6
Exchange rate - increase of 20% 4.6 US$:R$ 33.7 25.0

Figure 22.2 Sensitivity analysis - pre-tax NPV at 5% discount rate

Source: AMC

 

Figure 22.3 shows the change in pre-tax NPV and IRR for different gold prices.

 

 

amcconsultants.com

247

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Figure 22.3 Pre-tax NPV and IRR sensitivities to changes in the gold price

Source: AMC

 

 

 

amcconsultants.com

248

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

23Adjacent properties

As defined in Form 43-101F1 an adjacent property means a property in which the issuer does not have an interest. The Tucano tenement ownership map is shown is Figure 23.1 and the details of that ownership are discussed in Section 4.

There are no adjacent properties.

Figure 23.1 Tenement ownership map

Sources: BDR

 

 

 

amcconsultants.com

249

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

24Other relevant data and information

To the authors knowledge, there is no other relevant data or information related to the Tucano Gold property required so as to make the report more understandable or not misleading.

 

 

 

 

 

amcconsultants.com

250

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

25Interpretation and conclusions
25.1Risk assessment

The main risks identified for the operation previously have been largely reduced over the years of operation by BDR. Some key risks and controls include:

Delays to obtain licencing and permitting; GPR is working closely with government agencies to ensure permitting is received by the required dates. No major issues identified to date.
Wet weather impacting mine production; Wet weather has a negative effect on mine production however there has been significant improvement in recent years with an ongoing campaign of road rock sheeting and maintenance.
Geotechnical stability of pit walls in the oxidized profile; Monitoring of pit walls and adhesion to the recommended mining parameters is enforced.
Control of mining dilution and loss; Geology department maintains tight control over ore mark-outs, ore spotting, blast monitoring, and floor clean up to reduce ore dilution and loss.
25.2Mineral Resources and Mineral Reserves
In the opinion of the QPs, the drillhole database for the Tucano Project is reliable for the purpose of Mineral Resource estimation.
Drilling on the Tap AB deposits has significantly increased the oxide resources and reserves in the AB1 area with high potential to add resources along strike of the Tap AB pit.
Mineral Resources and Mineral Reserves have been classified according to the Canadian National Instrument 43-101 (NI 43-101) Standards of Disclosure for Mineral Projects.
For reporting, the QPs tabulated the Mineral Resources within pit shells optimized using a gold price of US$1,500 per ounce of gold. Mineral Reserves were based on reserve modifying factors and a gold price of US$1,200 per ounce within pit designs which were based on optimized shells using US$1,150 per ounce for Tap AB and US$1,100 per ounce for Urucum and Tap C.
25.3Mining
BDR commenced open pit mining operations in 2011 after acquiring the former heap leach operation from New Gold in 2010.
U&M is the main mining contractor at Tucano.
Based on current Mineral Reserves and mine planning, the Tucano LOM production schedule extends from 2018 through to 2023 from the open pits, with a total of 1.07M oz of gold being produced during this period.
The risks to the Tucano Mine LOM plan and operations are currently considered to be low, with outcomes being sensitive to negative commercial trends that might develop in respect of the gold price, exchange rate, and the inflationary effect on labour and consumables.
25.4Processing

Tucano commissioned the CIL plant in November 2012 and during 2017 a total of 129,764 ounces of gold was recovered from 3.7 Mt of ore. The current plant expansion now in progress aims to increase blend ratio from 20% to 80% for sulphides. Gold recoveries are expected to improve to 93% with the ability to consistently achieve a grind sizing P80 of 75 μm following the the already commissioned ball mill and the addition of an oxygen plant and an extra leach tank in the circuit.

 

amcconsultants.com

251

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

25.5Production and all-in sustaining costs

In 2017, Tucano mine produced 129,764 at an AISC of US$1,180/oz. The 2017 AISC includes all mining, treatment, general and administrative costs, sustaining capital, and royalties which are incurred at the mine site. The AISC costs exclude depreciation, amortization and corporate general and administrative costs.

25.6Health and safety

Health and safety is actively promoted by the site Safety department through on-going education, training, monitoring, and development of a positive safety culture on site.

25.7Underground mining
The mine will be accessed by a single portal located at the northern end of the mine and twin declines (north and south) based on orebody strike length of >800 m.
Level interval of 20 m (based on 15 m production blastholes and the narrow width of some lodes) with crosscuts between the decline and the mineralization, every 20 vertical metres (vm).
AMC recommends developing the mine to use truck haulage for all material movement.
Declines have been designed to give equipment access to each production level. On each level a crosscut will be developed from the decline to the ore lode / lodes. Declines and crosscut development has been designed to 5.0 m W x 5.0 m H, sufficient to accommodate 30 t - 40 t trucks.
Ore drives have been designed to be 5.0 m H x 4.0 m W to accommodate production drills and 10 t load-haul-dump (LHD) units. Trucks will not enter the ore drives.
Evaluation of the planned production rate and scheduling indicates that the deposit supports 450 ktpa to 500 ktpa. Production rates vary from year to year depending on the number of production fronts becoming available in different areas of the mine. The production rate could be further optimized as part of any future Feasibility Study.
All waste will be tipped directly into stopes or trucked to surface.
Approximately 2.4 Mt of ore at an average grade of 3.6 g/t Au will be mined and processed over the eight-year mine life.
All ore production and mine development will be done by contractors; this includes all waste rock filling.
Blasting will be undertaken primarily with ANFO and non-electric detonators. In conditions that are wet, bulk emulsion explosives will be utilized.
Ventilation will be provided via a “pull” system with primary fans located on surface at the top of each of two primary exhaust raises.
With the infrastructure airflow and leakage and balancing allowances, the total airflow determination based on the diesel fleet size is 350 m3/s.
Major scheduling assumptions driving these production rates include: decline and crosscut advance of 140 m/month, ore drive advance of 60 m/month, production rate from stoping of 10,000 t/month for both Up-Hole retreat and Benching stopes, backfilling rate of 12,000 m3 per month, per stope, for Benching stopes. All scheduling assumptions are based on industry benchmarked data.
Scheduling undertaken has been based on maintaining a near constant number of primary mobile equipment in both the North and South declines.
Workforce size at full production is estimated to be 236 employees. Employees working underground will work 7 hr shifts, but be paid for 8 hrs on site with the additional hour allowed for meal breaks, showering etc. The estimated working time “at the face” for underground workers is estimated to be 5 hrs and 45 mins.

 

amcconsultants.com

252

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

The underground workforce will consist of 6 crews working three 8 hr shifts per day Technical support staff, mining supervisors and general and administration employees will work a 5 day per week schedule.
The mine will use modern trackless mobile equipment for the development and stoping operations.
The underground mine would use some of the existing infrastructure built for the open pit operations such as the explosives magazines and warehouse.
Mining costs are estimated to be US$71.67/t of ore milled and total operating costs, inclusive of processing and G&A, are estimated to be US$88.67/t of ore milled.
The economic assessment indicates that the Project has potential to be developed into an economically viable, underground gold mine.

 

 

 

amcconsultants.com

253

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

26Recommendations
26.1Operations

The key objectives for Tucano are:

To operate on a “Zero Harm” safety and environmental tolerance basis.
Reduce costs and improve productivity of the operation.
Provide on-going training for employees.
Maintain a close reconciliation between planned production and actual production ounces.
To extend the mine life through the focused resource targeting and definition drilling to increase reserves. With the upgraded mill expected to be completed in November 2018, the focus will shift to targeting high grade oxide and sulphide resources that can be incorporated into the mine plan.
Maintain reconciliation studies and update the modelling factors accordingly for the determination of Mineral Resource and Mineral Reserve estimates.
Boost company resources by new discoveries in green field areas outside of the mining concession.
To achieve the above objectives in a socially responsible manner.
26.2Exploration and Resource Delineation
26.2.1Near mine and resource definition

Near mine resource definition in 2018 will focus on converting high grade Inferred Mineral Resources to Indicated Mineral Resources in areas occurring immediately outside the current reserve pits as well as locating new extensions to mineralization previously untested. With the plant upgrade planned to be complete in November 2018, the focus shifts from testing mainly oxide resources to both oxide and sulphide high grade mineralization that will increase open pit reserve and provide near term mill feed. A key area will be the poorly tested gap between the Urucum North and Urucum Central North pit areas where recent drilling has intersected strong mineralization. Other areas to extend the reserve include below the Urucum CN reserve pit, Tap AB1 Neo North, and Torres.

26.2.2Regional exploration

Regional exploration will work through a ranked list of targets with the aim to locate a major new discovery outside the mine corridor. Exploration will range from first pass stream sediment sampling, soil and auger drilling in the green field areas and RC and diamond drilling to define mineralization at the more advanced projects. Currently a program of stream sediment sampling has been completed at Serra da Canga East and is being followed up with soil sample lines and mapping. A program of detailed airborne EM and ground IP is being reviewed for 2018. Total budget for Resource Definition, Near Mine Exploration and Regional Exploration in 2018 is US$6.02M. The majority of this cost relates to RC and Diamond Drilling as detailed in Table 26.1 below.

 

 

amcconsultants.com

254

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Table 26.1 2018, Resource Definition, Near mine, and regional exploration budget

Summary Description Total m Budget US$
Resource conversion RC 5,000 651,515
Resource conversion DD    
Resource conversion PW / Auger    
Resource conversion Soil    
Near mine RC 12,500 1,628,788
Near mine DD 3,000 545,455
Near mine PW / Auger 2,100  
Near mine Soil    
Regional exploration RC 7,700 600,000
Regional exploration DD 2,500 390,909-
Regional exploration PW / Auger 3,600 -
Regional exploration Soil 9,290 (samples)  
Total fixed labour     316,697
Total fixed on costs     1,258,792
Total Geology laboratory     287,273
Total Geophysical surveys     136,364
Total Archaeological surveys     212,121
Total Budget     6,027,914

RC = Reverse Circulation Drilling, DD = Diamond Drilling, PW = Rotary Air Blast Drilling (Airtrack blasthole "PW" rig), Auger = Man-portable motorized auger. PW/Auger and Soil Sampler costs captured under fixed labour costs.

26.3Underground mining

The following recommendations are made in regard to the underground operation:

Further drilling and investigation work aimed at upgrading Inferred Mineral Resources and increasing the geotechnical and hydrogeological understanding of the deposit is recommended to consolidate the design basis for the project.
AMC recommends advancing the project to the FS stage. Opportunity exists to stage the project such that the second ramp is delayed until production from the first ramp proves successful and mining costs are better understood.
AMC recommends developing and operating the underground mine with contractors, this resolves any issues regarding supply of an experienced underground work force and allows for a reduction in upfront capital expenditure for mobile equipment.
Based on the current diamond drilling density and due to the nature of the gold mineralization (i.e. relatively coarse particle size) it is difficult to estimate gold grades within the mineralized zones accurately. AMC recommends that underground ore drive development, mapping, and sampling should be used to better define the mineralization.
AMC recommends that further geotechnical analysis is carried out to facilitate design and the efficient recovery of pillars. Detailed geotechnical modelling is recommended during the FS stage. This will also assist with understanding of the potential dilution particularly in the narrower veins.
Further metallurgical test work is recommended particularly on the primary sulphide material that will be extracted from underground. There is a risk that unexpected changes to metallurgical performance and gold recovery may occur.
Further environmental work is required during the FS stage to ensure that the underground operations do not present any problems in terms of environmental compliance. Any compliance problems could inadvertently delay the project or add additional unplanned costs to the project.

 

amcconsultants.com

255

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

Additional drilling is recommended to convert Inferred Resource to Indicated Resource and increase the underground Mineral Reserves. This is likely to have a positive impact on the project economics.
Opportunities exist to reduce capital costs for the underground project through locally constructed surface change rooms and offices rather than rental and may be an inexpensive alternative. The use of less expensive Scania P420 trucks for underground haulage once the decline roadway (floor) has been prepared and graded is also an opportunity. These options should be evaluated.

 

 

 

 

 

 

amcconsultants.com

256

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

 

 

27References

AMC Consultants 2016, Urucum Deeps Prefeasibility Study, BDR Resources Ltd. AMC Consultants: Melbourne, Australia. Report: AMC Project 115058.

Ausenco and SRK Consulting 2011, Beadell Resources Ltd Tucano Gold Project Feasibility Study Report, Ausenco Minerals and Metals & SRK Consulting: Perth, Australia. Report no. 2027-RPT-0037 Revision Number D.

Batelochi, M. 2015, 2015 Technical Mineral Resources Evaluation Report Tucano Project - Tap C & Gap Deposit, Gold Deposit in Pedra Branca Amapari - Amapa State - Brazil. M. Batelochi, Soluções em Geologia e Mineração Ltda; São Paulo Brazil.

Batelochi, M. 2016, 2016 Technical Mineral Resources Evaluation Report Tucano Project - Urucum Deposit, Gold Deposit in Pedra Branca Amapari - Amapa State - Brazil. M. Batelochi, Soluções em Geologia e Mineração Ltda; São Paulo Brazil.

Batelochi, M. 2017, 2017 Technical Mineral Resources Evaluation Report Tucano Project - Duckhead Deposit, Gold Deposit in Pedra Branca Amapari - Amapa State - Brazil. M. Batelochi, Soluções em Geologia e Mineração Ltda; São Paulo Brazil.

Costa, A. 2005. Levantamento Geofisico. Technical Report, January 2005. AFC Geofisica Ltda for MPBA.

Harrier Project Management 2017, Expansion Project Feasibility Study: Beadell Resources - Tucano Gold Project, Harrier Project Management: Perth, Australia. Report: Expansion Project_FS_Beadell Resources Tucano Mine Draft May Master.

Klinkert,P and Van den Berg, H. 2001. SPECTREM Survey of the Amapa Area, April 2001. Exploration and Acquisition Division, Anglo Operations Limited.

Potvin, Y. 1988. Empirical open Stope Design in Canada, November 1988, Universtity of British Columbia, BC, Canada.

Srivastava, M. R. and Isaacs, E. 1989, An Introduction to Applied Geostatistics. Oxford University Press, New York.

SRK Consultores do Brasil Ltda 2011, Plano de Controle Ambiental PCA (Environmental Control Plan), SRK Consultores do Brasil Ltda : Belo Horizonte, MG, Brasil. Report: SRK 031.11 30 de Setembro de 2011 - Revisão 02.

Tan, P. 2013, Urucum_East_Resource_Report_v1, Aug 2013, Beadell Internal Report.

Tomlinson, A. Jurza, P. Li, D. Trunfull, J. and Peters, P. 2015. Tucano Project Brazil - Geophysical Data Processing, 4 November 2015. Southern Geoscience Consultants: Perth, Australia. Report No. SGS3014.

Walter, B.M.T.; Cavalcanti, T.B. (eds. tec.) 2005. Fundamentos para a coleta de germoplasma vegetal. Embrapa Recursos Genéticos e Biotecnologia, Brasília, DF.

amcconsultants.com

257

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

28QP Certificates

Brian Richard Wolfe

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Brian Richard Wolfe, MAIG, and I am the Principal Resource Geologist of the firm of International Resource Solutions Pty Ltd of 71 Watkins St White Gum Valley, WA 6162, Australia.
2.I am a practicing geologist registered with the Australian Institute of Geoscientists. My membership number is 4629.
3.I graduated with a BSc Degree (Hons) in Geology in 1992 from the National University of Ireland, Dublin, and hold a Postgraduate Certificate in Geostatistics from Edith Cowan University (2007).
4.I have practiced my profession for a total of 24 years since 1993. I have experience in exploration geology, mining geology and geostatistical modelling, and estimation of mineral resources. My previous relevant experience on deposits, which are similar in nature to that discussed in the Report, include Agbaou gold deposit (Cote d’Ivoire), Bibiani gold deposit (Ghana), Kobada gold deposit (Mali), Sabadola gold deposit (Senegal), and numerous others during more than 15 years spent working in various capacities on similar projects in the region and worldwide.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project between 30 July 2015 and 3 August 2015.
7.I have previously been engaged with respect to the Tucano Gold Project by Beadell Resources Limited in my capacity as an Independent Consulting Resource Geologist to undertake Resource Estimation studies since 2015.
8.I am responsible or jointly responsible for preparing or supervising the preparation of Sections 1 (1.1 – 1.2, 1.4 – 1.9, and 1.17 – 1.18), Section 4.1, Sections 5 - 12, Section 14 (portions relating to open pit resources only), Section 23, Section 25.2, Section 26.2, and Section 27 (jointly) of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Gold Project and the Issuer (Beadell Resources Limited) pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have, nor do I expect to receive, a direct or indirect interest in the Tucano Gold Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, any securities of Beadell Resources Ltd or any associate or affiliate of such company.

 

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

Brian Richard Wolfe

 

amcconsultants.com

258

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Nigel Arthur Spicer

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Nigel Arthur Spicer, C.Eng., MIMMM, and I am a Principal Mining Engineer of the firm of Minesure Pty Ltd of 12 Redmond Street, Salter Point, WA, Australia. My residential address is 12 Redmond Street, Salter Point, WA, Australia.
2.I am a practicing mining engineer registered with the Institute of Materials, Minerals and Mining (IMMM). I am a Chartered Engineer (C.Eng. MIMMM) and my membership number is 43912.
3.I am a graduate of the University of Wales and hold a Bachelor of Science in Mining Engineering.
4.I have practiced my profession continuously since 1974 during which I have estimated Ore Reserves for gold and base metal projects located in Africa, Asia, North and South America, and elsewhere. I have managed open pit and underground mining operations in Africa, Asia and Australia and compiled feasibility studies for projects in Africa, North America, South America, Asia, Europe, and Russia. My previous experience has included deposits which are similar in nature to that discussed in the Report.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project area follows:
30 July 2015 – 1 August 2015,
5 September 2015 – 27 September 2015
14 November 2015 – 6 December 2015
28 January 2016 – 28 February 2016
24 January 2017 – 8 February 2017
7.I have previously been engaged with respect to the Tucano Project. I undertook a due diligence review of the Tucano Project in December 2009.
8.I am responsible for relevant parts of Sections 1, 3, 15, 16, 22, and 25 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

 

Nigel Arthur Spicer

 

amcconsultants.com

259

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Marcelo Antonio Batelochi

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Marcelo Antonio Batelochi, MAusIMM (CP), and I am a Principal Resource Geologist of the firm Soluções em Geologia e Mineração Ltda. My residential address is Av. Escola Politécnica, 942 – Bloco C3, Apto 41, São Paulo, São Paulo, Brazil.
2.I am a practicing geologist registered with the AusIMM - The Australasian Institute of Mining and Metallurgy. My membership number is 205477.
3.I hold a Bachelor of Honors degree from the School of Geology at UNESP - São Paulo State University, Brazil, in 1991.
4.I have practiced my profession continuously since 1992, during which I have more than 20 years of experience in the mineral resource evaluation of Iron, Copper / Gold, Nickel, Bauxite, REE, and PGE Deposits, as employee of Rio Tinto (12 years), Vale (4 years), Ferrous Resources (6 years), and five years as Independent Consultant (“MB Geologia”).

I have worked at Tucano deposits since 2012 carrying out Mineral Resources Estimates as independent consultant for Urucum, Urucum Underground, Tap-AB and Tap C + Gap, and Duckhead. Also, Tartarugalzinho Project.

My previous experience has included gold deposits of Yamana Gold (included Brio Gold), Aura Minerals and PA-Gold as a Consultant and Qualified Person. Specifically, “Morro do Ouro” deposit, where I worked for 10 years as manager of geology and mining planning (when it belonged to Rio Tinto).

5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project 4 times: January and May of 2012, January 2013, October 2013, February 2015, and March 2018.
7.I have not previously been engaged with respect to the Tucano Project in any capacity.
8.I am responsible for preparation of Section 20, and relevant parts of Sections 1, 4, 14, 26, and 27 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

Marcelo Antonio Batelochi

 

amcconsultants.com

260

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Ruy Lacourt Rodrigues

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Ruy Lacourt Rodrigues, SME – RM, and I am a Principal Mining Engineer of the firm LOM Consultants of Av. Alvares Cabral, 593 - Sala 1301 – Lourdes, 30 170-912 - Belo Horizonte – MG, Brazil.
2.I am a mining engineer, registered in the Brazilian regional council of engineering and agronomy (Conselho Regional de Engenharia e Agronomia, CREA) at the State of Bahia chapter (CREA BA 20655 D) since 1988. I am also a Registered Member of the Society for Mining, Metallurgy and Exploration, Inc. (SME), in the United States of America (SME 4172669RM) since 2014.
3.I graduated from the Universidade Federal de Ouro Preto, Brazil, in 1986 with a Bachelor of Science degree in Mining Engineering and a Master of Science degree in Mine Economics earned at the same institution in 2007.
4.I have worked as a mining engineer for 31 years since my graduation. My relevant experience to the Technical Report includes mining engineering, mine project and business development, planning and operations for gold and base metals covering mine project and planning, equipment specification and definition of personnel needs, mine operations and maintenance of mining equipment and infrastructure. My previous experience has included deposits which are similar in nature to that discussed in the Report.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project in April 2018.
7.I have not previously been engaged with respect to the Tucano Project in any capacity.
8.I am responsible for preparation of relevant parts of Sections 5 and 18 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

 

Ruy Lacourt Rodrigues

 

amcconsultants.com

261

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Juan Jose Moreno Dellepiane

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Juan Jose Moreno Dellepiane, MIEAust, CPEng., and I am a Principal Geotechnical Engineer of the firm SRK Consulting of 10 Richardson Street, West Perth, WA, Australia.
2.I am a practising civil engineer registered in Australia as Chartered Professional Engineer (CPEng.) Member with the Institute of Engineers Australia (MIEA), my membership number is 3667986.
3.I am a graduate of the Pontifical Catholic University of Peru and hold a title of Civil Engineer, August 1992.
4.I have practiced my profession continuously since 1992 during which I have worked in diverse soil mechanics projects, earthworks design, design and operation of tailings facilities for projects located in Africa, Asia, North and South America, specifically in Brazil. My specific experience with the Tucano Gold Mine includes the design of the tailings storage facilities (TSF): Tap D, North Mill Pond, West Pond Phase 1, West Pond Phase 2.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project area as follows:
6 January 2014 – 7 January 2014
16 November 2014 – 18 November 2014
11 November 2015 – 16 November 2015
19 October 2016 – 21 October 2016
7.I have previously been engaged with respect to the Tucano Project in any capacity.
8.I am responsible for preparation relevant parts of Section 18 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 23 May 2018

Original Signed and Sealed by

 

 

Juan Jose Moreno Dellepiane

 

amcconsultants.com

262

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Peter Robin O’Bryan

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Peter Robin O’Bryan, MAusIMM (CP), and I am a Principal Mining Engineer of the firm Peter O’Bryan and Associates of 43 York Street, Subiaco, WA, Australia. My residential address is 142 Tower Street, West Leederville, WA, Australia.
2.I am a practicing mining geotechnical engineer and registered Chartered Professional with the Australasian Institute of Mining and Metallurgy (AusIMM), Membership Number 203335.
3.I am a graduate of the University of New South Wales Bachelor of Engineering (Mining) and James Cook University, Master of Engineering Science (Rock Engineering).
4.I have practiced my profession continuously since 1982 during which I have provided mining geotechnical services for investigation, mine evaluation and mine operation for projects located in Australia, Africa, Asia, Canada, North and South America, Spain, and Eastern Europe. I have contributed to compilation and due diligence of feasibility studies for projects in Africa, Australia, Canada, and Asia. My previous experience has included deposits and operations which are similar in nature to that discussed in the Report.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project in September 2014 (4 days on site) and June 2015.
7.I have previously been engaged with respect to the Tucano Project. I spent 5 days on site in May 2015.
8.I am responsible for preparation of relevant parts of Section 16 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contain all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

 

Peter Robin O’Bryan

 

amcconsultants.com

263

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Raymond Henry Walton

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Raymond Henry Walton, P.Eng., and I am President and Principal Metallurgist of the firm Ray Walton Consulting Inc (RWC Inc.) of 182 DeGraaf Crescent, Aurora, Ontario, Canada, L4G 0X1.
2.I am a Professional Engineer, registered with the Association of Professional Engineers of Ontario (APGO), no. 90294521, since 1991.
3.I am a graduate of Brunel University, Uxbridge, Middlesex, 1977, where I obtained a B.Tech (Hons) degree in Materials Science and Technology.
4.I have 41 years of experience in process design and engineering, project management, commissioning and metallurgical plant operations. I have practiced my profession continuously since 1977. My relevant experience in copper and gold metallurgy, includes 9 years in operations, 20 years with engineering companies and 9 years as a Senior Director, Process Design within a large corporate Capital Projects group. I have been responsible for corporate oversight, feasibility studies, project evaluations, engineering, commissioning as well as operations on a large number of gold and copper projects around the world.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have personally visited the Tucano Project in January 2016.
7.I have previously been engaged with respect to the Tucano Project as a Consultant Metallurgist.
8.I am responsible for preparation of relevant parts of Sections 13, 17, and 25.4 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

 

Raymond Henry Walton

 

amcconsultants.com

264

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Gary Methven

I am a Qualified Person of the report entitled “Technical Report Mineral Resource and Reserve Update for the Tucano Gold Mine, Amapa, Brazil” dated 11 May 2018, (the “Report”), and I hereby state:

1.My name is Gary Methven, P.Eng., and I am the Underground Manager and Principal Mining Engineer of the firm AMC Mining Consultants (Canada) Ltd. of 202-200 Granville Street, Vancouver, British Columbia, Canada, V6C 1S4.
2.I am a practicing mining engineer registered with the Engineers and Geoscientists of British Columbia (License #180019), a member of the Registered Professional Engineers of Queensland (License #06839), and a member of the Australian Institute of Mining and Metallurgy (CP).
3.I graduated from the University of Witwatersrand in Johannesburg, South Africa with a Bachelor of Science degree in Mining Engineering in 1993.
4.I have relevant experience precious and base metal deposits, mine infrastructure, design and planning, mine production and financial evaluation, reserve estimation, technical reviews, and technical studies.
5.I am a “qualified person” as that term is defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects) (the “Instrument”).
6.I have not visited the Tucano Project area.
7.I have previously been engaged with respect to the Tucano Project. I undertook Mineral Reserve estimation for the Urucum North underground mine as of 30 June 2017.
8.I am responsible for preparation of Sections 2, 19, 21, and 24, and relevant parts of Sections 1, 3, 15, 16, 22, 25, and 26 of the Report.
9.At the effective date of the technical report, to the best of my knowledge, information, and belief, the above parts for which I am responsible contains all scientific and technical information that is required to be disclosed to make the technical report not misleading.
10.I am independent of the Tucano Project pursuant to Section 1.5 of the Instrument.
11.I have read the National Instrument and Form 43-101F1 (the “Form”) and the parts of the Report for which I am responsible have been prepared in compliance with the Instrument and the Form.
12.I do not have a direct interest in the Tucano Project of Beadell Resources Ltd, and I do not beneficially own, directly or indirectly, securities of Beadell Resources Ltd.

 

Effective Date: 11 May 2018

Signed Date: 17 May 2018

Original Signed and Sealed by

 

 

Gary Methven


amcconsultants.com

265

Mineral Resource and Reserve Update for the Tucano Gold Mine

Great Panther Silver Limited

718060

Our offices

Australia    

Adelaide

Level 1, 12 Pirie Street

Adelaide SA 5000 Australia

T       +61 8 8201 1800

E       adelaide@amcconsultants.com

 

Brisbane

Level 21, 179 Turbot Street

Brisbane Qld 4000 Australia

T       +61 7 3230 9000

E       brisbane@amcconsultants.com

 

Melbourne

Level 29, 140 William Street

Melbourne Vic 3000 Australia

T       +61 3 8601 3300

E        melbourne@amcconsultants.com

 

 

Perth

Level 1, 1100 Hay Street

West Perth WA 6005 Australia

T       +61 8 6330 1100

E       perth@amcconsultants.com

Canada    

Toronto

TD Canada Trust Tower

161 Bay Street, 27th Floor

Toronto, ON M5J 2S1 Canada

T       +1 416 640 1212

E        toronto@amcconsultants.com

 

Vancouver

200 Granville Street, Suite 202

Vancouver BC V6C 1S4 Canada

T       +1 604 669 0044

E       vancouver@amcconsultants.com

 

Singapore

  Russia

Singapore

30 Raffles Place, Level 17 Chevron House

Singapore 048622

T       +65 6809 6132

E        singapore@amcconsultants.com

 

Moscow

ul. Bakhrushina 32/1

Moscow 115054 Russian Federation

T       +7 495 134-01-86

E        moscow@amcconsultants.com

United Kingdom    

Maidenhead

Registered in England and Wales

Company No. 3688365

Level 7, Nicholsons House

Nicholsons Walk, Maidenhead

Berkshire SL6 1LD United Kingdom

T       +44 1628 778 256

E        maidenhead@amcconsultants.com

Registered Office: Ground Floor,

Unit 501 Centennial Park

Centennial Avenue

Elstree, Borehamwood

Hertfordshire, WD6 3FG United Kingdom

   

 

amcconsultants.com