Experimental determination of the liquidus in the high basicity region in the Al2O3(30 mass%) - CaO - MgO - SiO2 system

The liquidus in the high basicity region in the Al2O3(30 mass%)-CaO-MgO-SiO2 system were determined experimentally at 1773 and 1873 K using the quench technique followed by EPMA analysis. Based on the experimental data, a phase diagram of the Al2O3(30 mass%)-CaO-MgO-SiO2(<20 mass%) section was constructed for 1773 and 1873 K. The solubilities of 2CaO.SiO2 and 3CaO.SiO2 at 1773 K were found to be considerably higher in comparison with the existing phase diagram. Even the solubility of MgO at 1873 K was found to be somewhat higher. In addition, the activities of MgO, CaO and Al2O3 at 1773 K were estimated using the phase diagram information.