PROPERTY, PLANT AND EQUIPMENT

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

NOTE 6 - PROPERTY, PLANT AND EQUIPMENT

The following table indicates the carrying value of each of the major classes of our depreciable assets:

	December 31,
(In millions)	2023		2022
Land, land improvements and mineral rights	$	1,389	$	1,388
Buildings	946		921
Equipment	9,680		9,289
Other	302		238
Construction in progress	590		552
Total property, plant and equipment1	12,907		12,388
Allowance for depreciation and depletion	(4,012)		(3,318)
Property, plant and equipment, net	$	8,895	$	9,070
1 Includes right-of-use assets related to finance leases of $306 million and $408 million as of December 31, 2023 and 2022, respectively.

We recorded depreciation expense of $932 million, $988 million and $848 million for the years ended December 31, 2023, 2022 and 2021, respectively. Depreciation expense for the year ended December 31, 2022 includes $23 million of accelerated depreciation related to the decision to indefinitely idle the coke facility at Middletown Works and $68 million of accelerated depreciation related to the indefinite idle of the Indiana Harbor #4 blast furnace.

During the year ended December 31, 2022, we announced the permanent closure of Mountain State Carbon, which resulted in a $29 million asset impairment charge.

The net book value of the mineral and land rights are as follows:

	December 31,
(In millions)	2023		2022
Mineral rights:
Cost	$	783	$	780
Depletion	(258)		(225)
Net mineral rights	$	525	$	555
Land rights	$	427	$	434

We recorded depletion expense of $33 million, $38 million and $46 million for the years ended December 31, 2023, 2022, and 2021, respectively.