Solid Waste Production
Cement kiln dust, or CKD, is
created during the third stage of manufacturing
when clinker is formed. Electrostatic and bag
filters capture the dust for recycling. The industry
recycles more than 75 percent of cement kiln dust—nearly
eight million tons each year—directly back
into the cement kiln as raw material. Recycling
this byproduct also reduces the need for limestone
and other raw materials and helps conserve energy.
Other uses for CKD include agricultural soil beneficiation
and soil stabilization.
Beginning in 1990, the Portland Cement Association has tracked the amount of CKD sent to landfills. Over that time period the amount of CKD placed in landfills has decreased dramatically and when compared to the clinker production, the amount of CKD per unit of clinker had decreased at an even greater rate.
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