4. PROPERTY, PLANT AND EQUIPMENT, NET

3 Months Ended

Mar. 31, 2021

Property, Plant and Equipment [Abstract]

4. PROPERTY, PLANT AND EQUIPMENT, NET

Property, plant and equipment, net consist of the following:

	March 31, 2021			December 31, 2020
At cost:
Mineral rights	$	2,934,951		$	2,955,780
Buildings		63,573,495			64,024,667
Plant and machinery		256,579,799			258,400,710
Motor vehicles		6,507			6,553
Furniture, fixtures and office equipment		3,295,179			3,318,564
Construction in process		18,127,541			12,095,565
Total		344,517,472			340,801,839
Less: Accumulated depreciation and amortization		(176,040,608	)		(173,212,554	)
Impairment		(18,510,233	)		(18,641,596	)
Net book value	$	149,966,631		$	148,947,689

The Company has certain buildings and salt pans erected on parcels of land located in Shouguang, PRC, and such parcels of land are collectively owned by local townships or the government authority. The Company has not been able to obtain property ownership certificates over these buildings and salt pans. The aggregate carrying values of these properties situated on parcels of the land are $18,720,653 and $19,302,600 as at March 31, 2021 and December 31, 2020, respectively.

During the three-month period ended March 31, 2021, depreciation and amortization expense totaled $4,102, 929, of which $1,816,782, $163,233 and $2,122,914 were recorded in direct labor and factory overheads incurred during plant shutdown, administrative expenses and cost of net revenue, respectively.

During the three-month period ended March 31, 2020, depreciation and amortization expense totaled $3,453,563, of which $2,578,771, $201,406 and $673,386 were recorded in direct labor and factory overheads incurred during plant shutdown, administrative expenses and cost of net revenue, respectively.