Cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (2,095)	$ (9,086)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	611	962
Accretion of asset retirement obligation	262	249
Decrease (increase) in derivative at fair value, net		254
Loss (gain) on trading securities	12	(20)
Write off of deferred financing costs	352	59
Asset write off		100
Gain on sale of assets	(17)	(525)
Stock compensation	1,593	859
Changes in operating assets and liabilities from continuing operations:
Increase in lease receivable		376
Decrease (increase) in prepaid expenses and other assets	57	(506)
Increase in inventories	(1,279)	(53)
Increase in value added tax recoverable, net	(1,245)
Decrease (increase) in other long-term assets	373	(341)
Decrease in reclamation liability	33	(4)
Increase (decrease) in accounts payable and accrued liabilities	2,063	(810)
Increase (decrease) in other current liabilities	54	(1,156)
Decrease in deferred revenue	948	63
Increase (decrease) in other long-term liabilities	(308)	154
Net cash used in operating activities	$ 1,414	$ (9,484)