Effectiveness of Lime Kiln Flue Dust in Preventing Acid Mine Drainage at the Kauffman Surface Coal Mine, Clearfield County, Pennsylvania

A careful test of alkaline addition combined with special handling has been performed during mining of 27 acres of coal overlain by slightly to moderately pyritic overburden at the Kauffman Mine. Overburden holes indicate alkaline deficiencies of up to I 090 tons CaC0 3 /acre. Sulfur contents for 1-to 3-foot intervals average 0.26%S and range up to 4.4%. An adjacent mine produces severe AMD. Lime kiln flue dust, a waste product, was added in amounts adequate to neutralize maximum potential acidity. High-S zones were special-handled into compacted pods up to 2 ft. thick and covered by about 30% of the total lime requirement. About half the lime was spread on the surface prior to blasting and mixed during subsequent handling; the remaining lime was spread on the pit floor and beneath the topsoil.