Compaction Properties of Cement Kiln Dust

Abstract

Cement kiln dust (CKD) is a by-product of cement factories representing a real challenge for treatment due to the huge produced quantities of severe environmental hazards. Disposing of CKD requires compacting the raw material to the minimum volume due to the high cost of landfills. As the compaction of such material is not a common process especially in Egypt, an extensive experimental study program was planned and executed in order to define the best way of compacting the CKD.

Different factors affecting the compaction process were investigated in the current experimental study including the type of the mixing fluid and the effect of pre-curing of the CKD before compacting it either by fully submergence in water for a certain period, or by wetting it with a certain amount of water, and allowing certain periods for the chemical reaction to take place prior to drying and performing the compaction process.

Results of the performed experimental study showed that, using of salt water/seawater provides the optimum way for compacting the CKD to the maximum possible dry density at reasonable optimum water content. Using of waste used engines oil resulted in better efficiency of the compaction process in terms of the achieved maximum dry density with very limited amount of oil of about 0.205%, however oil is not preferred as a mixing fluid due its environmental hazards and the anticipated high cost as well.

Pre-curing/wetting of the CKD with water prior to compaction didn’t show a benefit, while on the contrary, entails using larger amount of water in the compaction process while achieving less maximum dry density compared to the normal case without pre-curing.

Due to the proximity of most of the cement factories in Egypt to the sea, the experimental study confirmed that using the salt water in compacting the CKD is the most favorable method. Also, the tests proved the ability to compact the CKD and hence disposal in landfills of reasonable volumes.