Property, Plant, Equipment and Mineral Rights and Reserves (Tables)

12 Months Ended

Dec. 31, 2012

Property, Plant, Equipment and Mineral Rights and Reserves [Abstract]

Property, plant, equipment and mineral rights and reserves

Property, plant, equipment and mineral rights and reserves consisted of the following:

	December 31,
	2012		2011
Mineral rights and reserves	$	48.6	$	52.5
Land		13.0		12.1
Buildings and improvements		104.9		97.5
Machinery and equipment		414.5		362.0
Construction in progress		32.6		25.2
		613.6		549.3

Range of useful lives to depreciate plant and equipment

The range of useful lives to depreciate plant and equipment is as follows:

Buildings and improvements	3-50 years
Machinery and equipment	1-24 years

Depreciation and depletion charged to income

Depreciation and depletion were charged to income as follows:

	2012		2011		2010
Depreciation expense	$	39.3	$	35.0	$	30.1
Depletion expense		1.6		2.6		1.2
		40.9		37.6		31.3