Phase equilibria in the TiO₂ rich part of the TiO₂–CaO–SiO₂-10wt.%Al₂O₃ system at 1773 K and 1873 K

The phase equilibria of the TiO₂–CaO–SiO₂-10wt.%Al₂O₃ system at the TiO₂ rich corner were investigated experimentally by the quenching method with subsequent electron probe microanalysis. The investigations were carried out at 1773 K and 1873K. The isothermal section at 1773 K contains one liquidus region and two solid–liquid coexistence regions, liquid-CaTiO₃ and liquid-TiO₂. And the isotherms of the CaTiO₃ primary phase field and TiO₂ primary phase field at 1773 K have been found in the TiO₂ rich part. At 1873K, the CaTiO₃ primary phase field and its isotherm have been determined. Based on the obtained fundamental data, the phase diagram has been established in the TiO₂ rich corner of the TiO₂–CaO–SiO₂-10wt.%Al₂O₃ system at 1773 K and 1873 K. From the obtained phase diagram, it can be found that the addition of 10% Al₂O₃ into TiO₂–CaO–SiO₂ system enlarges the range of the low-liquidus-temperature slags. The phase equilibria data can provide the foundation for the further full investigations on the crystallization and upgradation of the Ti-bearing slag from direct reduction-smelting processes of vanadium-titanium magnetites. - Highlights: • Phase diagram of TiO₂–CaO–SiO₂-10wt.%Al₂O₃ system at TiO₂ rich corner is established. • Isotherm of the CaTiO₃ primary phase field at 1773 K is found in the TiO₂ rich part. • Isotherm of the TiO₂ primary phase field at 1773 K is found in the TiO₂ rich part. • Isotherm of the CaTiO₃ primary phase field at 1873K is found in the TiO₂ rich part. • Addition of Al₂O₃ in TiO₂–CaO–SiO₂ enlarges range of low-liquidus-temperature slags.