MAHMOUD ELSAYED AHMED MOHAMED HASSAN OKASHA

Abstract

Cement kiln dust (CKD) is a by-product of cement factories representing a real challenge for treatment due to the huge produced quantities. It is considered a major health hazard where the Ministry of Environment recommended its beneficial utilization uses or getting rid of it. Disposing of CKD requires compacting the raw material to the minimum volume due to the high cost of landfills. The main objective of this research is to study ; i) the different methods to compact the cement kiln dust based on a detailed characterization of the materials, in order to get the maximum dry density from the used method as one of the uncommon processes of disposing of CKD, especially in Egypt and ii) the effect of mixing sand with cement kiln dust by different percentages on its properties as a useful way of recycling the CKD while enhancing the sand properties. Two extensive experimental study programs were planned and executed in this research. First of them consists of three groups were designed to define the best way of compacting the CKD. Different factors affecting the compaction process were investigated in the current 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. The second experimental study program consists of four groups were designed to study the effect of mixing sand with CKD by different percentages on its properties. Compaction, direct shear and California bearing ratio tests were conducted on the sand-CKD mixtures in order to evaluate the impact of CKD percentage addition. Feasibility of using the saltwater instead of fresh water in treating the CKD was investigated through the performed experimental study to benefit from the proximity of most of the cement factories in