China Nonferrous Metallurgy

The green and efficient extraction of titanium resources from titania-bearing blast furnace slag is a powerful guarantee for the continuous development of high-value-added titanium products. However, there is a lack of key thermodynamic data related to titania-bearing oxide slag systems, which seriously restricts the development of related titanium extraction processes. Based on the composition and mineral characteristics of typical titania-bearing blast furnace slag, combined with the “Phase Diagram” module of FactSage 8.2 thermodynamic software and the “FactPS” and “FToxid” databases, the evolution of equilibrium coexisting phases was determined in the temperature range of 1400~1600℃ and the oxygen partial pressure range of 0.21~10-18atm in the present work. The results show that when the temperature is constant, as the oxygen partial pressure decreases, the range of the liquid phase region first increases and then decreases, and titanium is reduced step by step; While the oxygen partial pressure is constant, as the temperature increases, the liquid phase region gradually enlarged, the liquid phase-CaTiO₃ first increases slightly and then decreases slightly with the increase of temperature, and moving in the direction of increasingw(CaO)/w(SiO₂) ratio. The liquid phase-TiO₂ first increases greatly and then decreases slightly. The research results are important for understanding the evolution of titania-bearing phases under different process parameters, and then developing a more environmentally friendly and more efficient titanium resource extraction process.