INCOME TAXES (Tables)

12 Months Ended

Jul. 31, 2016

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

A reconciliation of income tax computed at the federal and state statutory tax rates including the Company’s effective tax rate is as follows:

	Year Ended July 31,
	2016			2015			2014
Federal income tax provision rate		35.00	%		35.00	%		35.00	%
State income tax provision rate, net of federal income tax effect		0.35	%		0.32	%		0.22	%
Total income tax provision rate		35.35	%		35.32	%		35.22	%

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

The actual income tax provisions differ from the expected amounts calculated by applying the combined federal and state corporate income tax rates to the Company’s loss before income taxes. The components of these differences are as follows:

	Year Ended July 31,
	2016			2015			2014
Loss before income taxes	$	(17,362,111)		$	(23,397,341)		$	(26,044,816)
Corporate tax rate		35.35	%		35.32	%		35.22	%
Expected tax recovery		(6,137,506)			(8,263,941)			(9,172,984)
Increase (decrease) resulting from
Foreign tax rate differences		230,148			223,980			286,071
Permanent differences		806,736			1,473,225			585,482
Prior year true-up		(647,307)			50,025			(79,672)
State tax rate true-up		(105,843)			(205,285)			(199,795)
Foreign exchange rate differences		129,015			144,242			97,565
Other		59,705			62,398			(10,431)
Change in valuation allowance		5,627,606			6,474,775			8,419,286
Tax adjustment from operations		(37,446)			(40,581)			(74,478)
Unrealized loss, other comprehensive loss		5,207			5,168			4,769
Deferred income tax benefit	$	(32,239)		$	(35,413)		$	(69,709)

Schedule of Income before Income Tax, Domestic and Foreign [Table Text Block]

The components of income (loss) from operations before income taxes, by tax jurisdiction, are as follows:

	Year Ended July 31,
	2016		2015		2014
United States	$	(16,488,447)	$	(22,612,974)	$	(25,009,106)
Canada		54,216		158,616		155,408
Paraguay		(927,880)		(942,983)		(1,191,118)
	$	(17,362,111)	$	(23,397,341)	$	(26,044,816)

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

The Company’s deferred tax assets (liabilities) are as follows:

	July 31, 2016		July 31, 2015
Deferred tax assets (liabilities)
Mineral property acquisitions	$	1,917,796	$	1,867,777
Exploration costs		10,648,043		10,931,265
Stock option expense		7,081,853		5,771,387
Depreciable property		(66,912)		78,651
Inventories		(3,632,178)		(2,530,383)
Asset retirement obligations		(220,209)		(316,136)
Other		271,468		333,026
Loss carry forward		49,565,476		43,802,183
		65,565,337		59,937,770
Valuation allowance		(65,570,544)		(59,942,938)
Deferred tax assets		(5,207)		(5,168)
Deferred tax assets, other comprehensive loss		5,207		5,168
Deferred tax liabilities
Mineral property acquisition		(643,825)		(676,064)
Net deferred tax liabilities	$	(643,825)	$	(676,064)

CANADA

Summary of Operating Loss Carryforwards [Table Text Block]

The Company’s Canadian net operating loss carry-forwards in Canadian dollars expire as follows:

July 31, 2027	$	183,105
July 31, 2028		629,788
July 31, 2029		769,072
July 31, 2030		1,314,392
July 31, 2031		2,210,551
July 31, 2032		761,843
July 31, 2033		69,854
July 31, 2034		61,769
July 31, 2035		41,173
July 31, 2036		9,952
	$	6,051,499

UNITED STATES

Summary of Operating Loss Carryforwards [Table Text Block]

The Company’s U.S. net operating loss carry-forwards expire as follows:

July 31, 2023	$	180,892
July 31, 2024		228,757
July 31, 2025		507,833
July 31, 2026		5,895,221
July 31, 2027		3,892,722
July 31, 2028		9,913,533
July 31, 2029		8,469,032
July 31, 2030		7,319,644
July 31, 2031		14,420,187
July 31, 2032		15,014,013
July 31, 2033		16,332,007
July 31, 2034		21,173,540
July 31, 2035		18,974,097
July 31, 2036		14,837,092
	$	137,158,570