UTILIZATION OF INDUSTRIAL-WASTES AND BY-PRODUCTS FOR THE SYNTHESIS OFSPECIAL CEMENTS

Calcium sulfoaluminate, which is the main component of low energy ceme nts, can be synthesised using pure and commercial raw materials, as we ll as industrial wastes and by-products. It has been found that indust rial process wastes like fly ash, blastfurnace slag, phosphogypsum and bauxite fines allow the synthesis of the binder to be performed at ab out 1200-degrees-C with high yield and satisfactory selectivity. Besid es the main mineral components calcium sulfoaluminate, dicalcium silic ate and anhydrite, a number of side products (minor mineralogical phas es) were also present. Furthermore, calcium sulfosilicate formed inste ad of dicalcium silicate in the presence of excess calcium sulfate.