A study of the refractory properties of selected clay deposit in Chavakali, Kenya

Abstract

A clay deposit in Chavakali of western Kenya was evaluated for its potential as refractory raw material. The collected clay sample was crushed, sieved and the chemical composition determined in percentage weight (wt %) of (SiO2, Al2O3, Fe2O3, etc) using Atomic Absorption Spectrophotometer (AAS). The samples were moulded into rectangular shaped bricks of 40mm height, 40mm width and 80mm length, allowed to dry and later fired up to a temperature of 10000C. Refractory properties like Compressive strength, Hardness, Linear shrinkage on firing, Apparent porosity and Density were determined using standard techniques. The result of chemical analysis indicated that the clay was composed of Silica (SiO2), 67.3%; Alumina (Al2O3), 16.67%; Iron Oxide (Fe2O3), 3.87%; Calcium Oxide (CaO), 0.37%; Potassium Oxide (K2O), 2.30%; Sodium Oxide (Na2O), 1.39%; and other traces. The physical and mechanical tests show that the clay has Cold Crushing Strength of 10.36MPa, Hardness of 40.080 GPa, Linear shrinkage of 6.17%, Apparent Porosity of 32.71% and Bulk Density of 2.77g/cm3. Chavakali clay can make better local refractor