Effect of B2O3 on the Melting Temperature and Viscosity of CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3 Slag

Fluorite is widely employed as a fluxing agent in metallurgical processes, inevitably leading to severe pollution. In this study, to promote the development of sustainable metallurgy, B2O3 is used as a fluxing agent of CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3 slag, acting as a replacement for CaF2. The effect of B2O3 on the melting temperature and viscosity of CaO–SiO2–MgO–Al2O3–TiO2–Cr2O3 slag was investigated using a melting-point and melting-rate measurement instrument and a melting physical property comprehensive measurement instrument. Scanning electron microscopy was used to observe the microstructure of the precipitated phase, and X-ray diffraction was used to identify its phase composition. The results indicated that both the melting temperature and viscosity decreased with increasing B2O3 content. Moreover, B2O3 had a significant influence on the morphology of the precipitated phase, particularly for the shape and size of the precipitated particles. Accordingly, with the increase in the B2O3 content, the composition of the precipitated phase and the corresponding diffraction peak intensities changed. The results of this study provide a theoretical and technical basis for the comprehensive utilization of Cr-containing high-titanium melting slag.