PATTERNS OF PHASE FORMATION DURING PRODUCTION OF HIGH-ALUMINA CEMENT CLINKER WITH THE ADDITION OF ZIRCONIUM DIOXIDE

The processes of phase formation in the ternary system CaO–Al2O3–ZrO2 under conditions of high-temperature solid-phase reactions as applied to the production of refractory high-alumina cements were studied. It has been established that in mixtures of “chalk – technical alumina – zirconium oxide” when heated to 900°C, rapid decomposition of CaCO3 occurs and the resulting CaO interacts with Al2O3 to form C12A7. At 1000-1100°C, the appearance of the ternary compound 7CaO*3Al2O3*ZrO2 is recorded in reaction mixtures. It has been shown that firing the raw mixture at 1200-1400°C allows obtaining high-alumina clinker with predominant phases CA2, CA and C7A3Z; CaZrO3, Al2O3 and ZrO2 are present in small quantities in the roasting products. The introduction of aluminum oxochloride AlOCl into the mixture accelerates the mineral formation processes.