Effects of the Addition of Corncob Ash on the Technological Properties of Ugwuoba Clay, Nigeria

Abstract

An investigation into the effects of combustible materials on the refractory properties of Ugwuoba clay, using corncob ash has been undertaken. Ugwuoba clay was sourced from Ugwuoba town in Oji River Local Government Area of Enugu State, Nigeria, while corncobs were collected at New Artisan Market in Enugu Metropolis. The clay was processed using standard beneficiation and purification procedures at the Ceramics Department of Projects Development Agency (PRODA), Enugu. The corncobs were calcined into amorphous ash by heating in a furnace at 650oC. The refractory blends were compounded at the ratio of 90:10, 80:20, 70:30, and 60:40 for Ugwuoba clay (UGC) to Corncob Ash (CCA) respectively. These blends were subsequently moulded into the standard test pieces for the various properties determination and subjected to firing at temperatures of 900oC, 1000oC, 1100oC and 1200oC. Thereafter, the fired samples were characterized for fired shrinkages, total shrinkages, apparent porosities, water absorption coefficients, apparent densities, bulk densities and cold crushing strengths. The results obtained for each of the blends showed that the values were within the tolerable limits for industrial refractories with the 20%CCA blends showing the best results when compared with the other blends. A conclusion is drawn to the effect that corncob ash can serve as good organic admixtures for refractory bricks production for the lining of melting furnaces in the metals industry, hence opening new frontiers for recycling of these agricultural wastes for environmental safety and economic development in Nigeria.