Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2022

Property, Plant and Equipment [Abstract]

Major Categories of Property, Plant and Equipment and Accumulated Depreciation and Depletion

The major categories of property, plant and equipment and accumulated depreciation and depletion are presented below:

	December 31,
(millions of dollars)	2022			2021
Mineral rights and reserves	$	604.9		$	554.7
Land		47.3			50.6
Buildings		209.8			229.2
Machinery and equipment		1,248.0			1,262.8
Furniture and fixtures and other		137.1			139.9
Construction in progress		41.5			59.2
		2,288.6			2,296.4
Less: accumulated depreciation and depletion		(1,238.2	)		(1,247.3	)
Property, plant and equipment, net	$	1,050.4		$	1,049.1