Melting Properties and Phase Composition Transformation of Ti-Bearing Electric Furnace Slags in CaO-SiO2-MgO-Al2O3-50%TiO2 System

This study aims to experimentally investigate the influence of several key factors, including basicity, Al2O3 content, TiO2 content, SiO2/Al2O3 ratio, and titanium reduction, on the melting properties of electric furnace slags containing titanium in the CaO-SiO2-MgO-Al2O3-50%TiO2 system. The findings revealed that the melting temperature decreased with an increase in the CaO/SiO2 ratio, Al2O3 content, and SiO2/Al2O3 ratio, while it increased with higher TiO2 content. To achieve a low melting temperature for the slags and an appropriate phase composition for titanium extraction, it is advisable to maintain a low CaO/SiO2 ratio within the range of 0.6-0.7, and an Al2O3 content of 13% is recommended. Higher TiO2 content is associated with elevated liquidus temperatures, while conversely, the SiO2/Al2O3 ratio exhibits an inverse relationship. Efforts were made to limit the titanium reduction during smelting to a maximum of 0.4. Anosovite (MgTi2O5), CaAl2Si2O8, Mg(Al, Ti)(2)O-4, spinel (MgAl2O4), augite (Ca(Mg, Fe, Al) (Al, Si)(2)O-6) and Ca12Al14O33 were the primary phases in titanium slag. The calculated viscosity results align with the trends observed in the melting property results. Furthermore, the liquidus temperatures were obtained through FactSage aligns with the pattern observed in the melting temperature. These findings will serve as a valuable technical foundation to support the development of the direct reduction smelting process for the comprehensive utilization of vanadium titanomagnetite.