SINTERING STUDIES ON PLASTIC CLAYS

Plastic clays are essential ingredients for ceramic body manufacture as binding agents for imparting plasticity, workability and green strength to raw materials. Seven clay samples which are mainly kaolinitic were chosen for the present studies. The mineralogy and crystallinity of the raw materials and the phase changes taking place during their sintering under different conditions were examined. The properties of the fired samples, such as water absorption, linear shrinkage and MOR were determined and a correlation of the strength of the sintered material with the microstructure was attempted. The observed variation in the properties was explained as a function of mineralogy, crystallinity and the amount and nature of the impurities present in the clays. The effect of the blending of an aluminosilicate gel and other mineral constituents with clays on their properties after sintering was also studied.