4. PROPERTY, PLANT AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

4. PROPERTY, PLANT AND EQUIPMENT, NET

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

	December 31, 2020			December 31, 2019
At cost:
Mineral rights	$	2,955,780		$	2,764,462
Buildings		64,024,667			59,880,567
Plant and machinery		258,400,710			234,669,007
Motor vehicles		6,553			6,129
Furniture, fixtures and office equipment		3,318,564			3,235,736
Construction in process		12,095,565			1,204,742
Total		340,801,839			301,760,643
Less: Accumulated depreciation and amortization		(173,212,554	)		(146,330,705	)
Impairment		(18,641,596	)		(17,434,989	)
Net book value	$	148,947,689		$	137,994,949

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 $19,302,600 and $19,894,947 as at December 31, 2020 and December 31, 2019, respectively.

During the year ended December 31, 2020, depreciation and amortization expense totaled $15,982,485 of which $5,512,920, $815,605 and $9,653,960 were recorded in direct labor and factory overheads incurred during plant shutdown, administrative expenses and cost of net revenue respectively.

During the year ended December 31, 2019, depreciation and amortization expense totaled $13,991,583 of which $ 10,796,085, $848,345 and $2,347,153 were recorded in direct labor and factory overheads incurred during plant shutdown, administrative expenses and cost of net revenue respectively.

There were no impairment losses recorded in the years ended December 31, 2020 and 2019. The increase in the impairment of $1,206,607 from $17,434,989 at December 30, 2019 was due to currency translation adjustment.