Note 3 - Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2024

Property, Plant and Equipment.

Schedule of Property, plant, and equipment

	December 31,
(In thousands)	2024		2023
Plant and equipment	$	331,899	$	290,060
Mining property and mineral rights		120,532		120,532
Construction in process		31,048		13,984
Capitalized mine development costs		199,595		174,260
Less: accumulated depreciation, depletion, and amortization		(201,055)		(139,745)
Total property, plant, and equipment, net	$	482,019	$	459,091

Schedule of Depreciation, depletion, and amortization

	Year ended December 31,
(In thousands)	2024		2023		2022
Depreciation of plant and equipment	$	37,283	$	30,913	$	24,132
Amortization of right of use assets (finance leases)		10,414		8,547		4,846
Amortization and depletion of capitalized
mine development costs and mineral rights		17,918		14,792		12,216
Total depreciation, depletion, and amortization	$	65,615	$	54,252	$	41,194