Property, Plant and Equipment

6 Months Ended

Jun. 30, 2022

Property, Plant and Equipment [Abstract]

The components of Property, plant and equipment, net are as follows:


(in thousands)	June 30, 2022		December 31, 2021		June 30, 2021
Land	$	38,630	$	39,162	$	39,367
Land improvements and leasehold improvements	91,542		91,122		93,166
Buildings and storage facilities	370,453		368,577		377,946
Machinery and equipment	949,142		936,476		921,190
Construction in progress	31,237		20,676		19,723
	1,481,004		1,456,013		1,451,392
Less: accumulated depreciation	717,561		669,984		627,829
Property, plant and equipment, net	$	763,443	$	786,029	$	823,563

Depreciation expense on property, plant and equipment used in continuing operations was $55.8 million and $62.5 million for the six months ended June 30, 2022 and 2021, respectively. Additionally, depreciation expense on property, plant and equipment used in continuing operations was $27.5 million and $31.4 million for the three months ended June 30, 2022 and 2021, respectively.

During the second quarter of 2022, the Company closed on the sale of the remaining assets of the Company's Frac Sand business for total consideration of $8.4 million resulting in a pre-tax gain of $3.7 million.