Note 3 - Property, Plant and Equipment (Tables)

6 Months Ended

Jun. 30, 2023

Property, Plant and Equipment.

Schedule of property, plant, and equipment

(In thousands)	June 30, 2023		December 31, 2022
Plant and equipment	$	251,002	$	232,885
Mining property and mineral rights		120,533		120,760
Construction in process		35,039		34,698
Capitalized mine development costs		165,812		153,436
Less: accumulated depreciation, depletion, and amortization		(114,822)		(111,937)
Total property, plant and equipment, net	$	457,564	$	429,842

Schedule of depreciation and amortization

	Three months ended June 30,				Six months ended June 30,
(In thousands)	2023		2022		2023		2022
Depreciation of plant and equipment	$	7,661	$	5,270	$	14,428	$	10,024
Amortization of right of use assets (finance leases)		1,999		1,383		3,881		2,097
Amortization and depletion of capitalized
mine development costs and mineral rights		3,896		3,130		7,098		6,342
Total depreciation, depletion, and amortization	$	13,556	$	9,783	$	25,407	$	18,463