CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets:
Cash and cash equivalents	$ 117,064	$ 141,984
Materials and supplies inventories, net – Note 3	2,794	2,808
Prepaids and deposits – Note 4	4,231	2,840
Income tax receivable	1,530	1,530
Interest receivable	539	459
Accounts receivable	0	2,771
Current assets	126,158	152,392
Property, plant and equipment, net – Note 5	54,142	54,832
Restricted cash – Note 6	34,682	33,982
Assets held for sale – Note 7	7,148	7,148
Prepaids – Note 4	600	600
Total assets	222,730	248,954
Liabilities:
Accounts payable and accrued expenses – Note 8	1,713	5,644
Debt, net – Note 9	2,328	2,328
Contract liabilities – Note 10	1,150	1,050
Other liabilities – Note 11	1,804	3,011
Current liabilities	6,995	12,033
Debt, net – Notes 9 and 20	137,527	132,690
Deferred gain on sale of royalty	29,837	29,837
Asset retirement obligation – Note 12	10,674	10,302
Warrant liabilities – Notes 13 and 14	59	786
Other liabilities – Note 11	24	0
Total liabilities	185,116	185,648
Commitments and contingencies – Note 22
Stockholders’ equity:
Common stock, $0.0001 par value; 1,400,000,000 shares authorized; 201,954,021 issued and outstanding at June 30, 2023, and 200,270,659 issued and outstanding at December 31, 2022 – Note 14	20	20
Additional paid-in capital – Note 14	735,543	733,437
Accumulated deficit	(697,949)	(670,151)
Total stockholders’ equity	37,614	63,306
Total liabilities and stockholders’ equity	$ 222,730	$ 248,954