Production and characterization of ceramic pieces obtained by slip casting using powder wastes

The growing world population in industrialized countries is resulting in an increasing consumption of raw materials and thus in a flood of waste. The recycling of materials and waste treatment techniques have drawn the attention from all different areas including industries, technology centers and universities. In the present work the main objective is to recover wastes from slate rock industry, using powder technology by slip casting process to produce ceramic pieces. The characterization of slate powder according to its mineral composition shows the presence of minerals like quartz, chlinoclore, albite, orthoclase and muscovite, which could be used as raw materials for ceramic products. We also have noted a close dependence on powder and additive concentration with the viscosity of suspension. The sintering study was accomplished through density and porosimetry essay, surface area evaluation among others. X-ray results coupled with thermal analysis have clearly indicated major structural transition at 500 and 900 °C. The results obtained after sinterization to 1000 °C showed that the sintering strongly influenced the structural transition occurred in slate. The results allow us to conclude that slate wastes can be used in the manufacture of ceramic pieces by slip casting. The optimized properties of pieces to different uses can be achieved by controlling the powder characteristics, the molding process and the sintering conditions.