Utilization of harzadous industrial alumina and iron wastes in the cement manufacturing process

Abstract

This research was conducted with a major aim of improving cement raw material mineralogical composition; hence produce affordable and better quality cement.

Limestone is a major component in the cement manufacturing process. E.A.P.C.C hauls high purity limestone from Sultan Hamud and low purity limestone (Kunkur) from Athi River town. The research looked into possible ways of utilizing alternative raw materials which could promote the use of a higher proportion of the near by available kunkur so as to reduce material haulage costs; hence overall lowering of product unit cost.

The raw materials available were deficient in alumina and iron for optimum production of cement hence the focus was to explore the possibility of other secondary materials which could enrich these components in the raw materials.

This research was conducted by testing-sev.e...ral materials containing alumina . The product which comformed with optimum qualitrsPecifications of cement was

found to be the final waste product from aluminium rolling mills which was termed as alumina dust. This highly hazardous material solved a major operation problem in the plant and solved the aluminium plants major waste disposal problem. Thus; this waste product resulted in

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~ Cleaner production in the aluminium rolling plant and steel mills by the recycling of the wastes in the cement industry. ~ Cost effective cement, which gives a costing of Ksh 916/t raw meal with

very low limestone requirements of 65.5% and a kunkur ratio of 32%. As compared to the previous costing of Ksh. 950/t raw meal and a high limestone requirement of 70% and a kunkur ratio of 26%. ~ Easier burning operation - appendix 6 figure 2. VVhichhas better burnability giving higher throughput averaging at 103 tph as compared to 91 tph.

~ Lower fuel consumption - appendix 6 figure 4. Where we achieved an efficiency of 921 kcal/kg as compared to 1131 kcal/kg on the previous mix. ~ Profitable waste disposal where the Aluminium industry sells this waste at