Phase Equilibria of Ti-bearing Electric Furnace Slags in the CaO-MgO-SiO2-13%Al2O3-50%TiO2 System

With the purpose of providing a fundamental understanding of equilibrium phase relationships in the CaO-MgO-SiO2-13%Al2O3-50%TiO2 system, the equilibrium phase relationships were experimentally determined from 1400 degrees C to 1500 degrees C in air using a high-temperature equilibration and quenching method. The single liquid phase, liquid-rutile (TiO2), liquid-anosovite (M3O5), liquid phase coexisting with anosovite and rutile, liquid phase coexisting with anosovite and spinel, liquid-spinel, liquid phase coexisting with perovskite and spinel, and liquid-perovskite (CaTiO3) were found. The realistic isotherms at 1400 degrees C, 1450 degrees C, and 1500 degrees C were obtained by comparing the experimental liquid phase results with the predicted results. A realistic phase boundary was confirmed based on the actual isotherm's cusp orientation, ensuring accuracy and precision. The minimum deviations, which are 146.71 degrees C, 123.26 degrees C, and 170.05 degrees C, respectively, were lower than the experimentally determined liquidus temperatures. In addition, the results of phase equilibrium experiments showed that, when the MgO content exceeded 5%, the corresponding liquid phase temperature increased with the increase of MgO content. This work is a further addition and refinement to the thermodynamics of titanium oxides.