Phase Equilibrium Study of the CaO-SiO2-MgO-Al2O3-TiO2 System at 1300°C and 1400°C in Air

Due to the importance of the physicochemical properties of slag in the recovery of low-titanium ores and by-products, the equilibrium phase relationships of the CaO-MgO-Al2O3-SiO2-TiO2 system were experimentally determined using a high-temperature equilibration and quenching method at 1300 degrees C and 1400 degrees C. The equilibrium information was obtained by scanning electron microscope-energy dispersive x-ray spectrometer. Perovskite, spinel and pseudobrookite solid solution phases with MgO center dot 2TiO(2) and Al2O3 center dot TiO2 end members were found to be coexisting with the liquid phase. The 1300 degrees C and 1400 degrees C isotherms were then constructed on a CaO-SiO2-TiO2-8 wt.% MgO-14 wt.% Al2O3 quasi-ternary section. Comparisons with predictions by Factsage and MTDATA indicated that the computational results agreed well only in the primary phase field of perovskite, while clear deviations existed within other primary phase fields. Therefore, the present results improve our knowledge about the utilization of titanium resources, and are also significant in providing novel equilibrium data for updating the related thermodynamic databases.