Phase Equilibria of Ti-Bearing Electric Furnace Slags in Air at 1400 °C in CaO–MgO–SiO2–13 wt pct Al2O3–50 wt pct TiO2 System

Abstract

Phase equilibria for the CaO–MgO–SiO₂–13 wt pct Al₂O₃–50 wt pct TiO₂ system were experimentally investigated at 1400 °C in air atmosphere, employing the high-temperature equilibration and quenching method. Seven distinct phases were identified, encompassing a liquid phase, a liquid phase with perovskite (CaTiO₃), a liquid phase with rutile (TiO₂), a liquid phase with anosovite (M₃O₅), a liquid phase with anosovite and rutile, a liquid phase with anosovite and spinel, and a liquid phase with perovskite and spinel. Additionally, an experimentally verified isotherm at 1400 °C was obtained and conducted a comparative analysis with predictions generated using FactSage software. Overall, the FactSage 8.1 software exhibited a notable tendency to overestimated the liquidus temperatures in the M₃O₅ and spinel phases regions when compared to the experimentally determined values. This disparity may be attributed to limitations in the FactSage 8.1 software database which lack of Al₂TiO₅ in the “FToxid-PSEU” solution species, as it indicated a large liquid phase region in the CaO–MgO–SiO₂–13 wt pct Al₂O₃–50 wt pct TiO₂ system at 1400 °C than what we experimentally determined.