This is the fine-grained, solid, very alkaline waste that is removed from the exhaust gases by air pollution devices on cement kilns. Much of this is unreacted raw material and can be recycled back into the production process. That which cannot be reused goes to a landfill. The Best Practices listed below only apply if the dust comes from the burning of non-hazardous waste.
Best Practices in Preventing Air or Water Pollution from Cement Kiln Dust
• Compact and periodically wet down cement kiln dust in landfills.
• At the site of the cement kilns, transfer the dust in enclosed covered vehicles and conveyance devices from enclosed tanks and containers within the buildings to the site of disposal and use means of transfer to the landfill that will not create a dust problem in the air. All such landfills must have liners to prevent leachate from moving down to the groundwater supply.
• If the cement kiln dust is used as part of an agricultural application, it must meet the concentration limits for arsenic, cadmium, lead, thallium, chlorinated dibenzodioxins, and dibenzofurans.