The Desulfurization Ability of a High Al2O3 Type CaO-SiO2-Al2O3-MgO-TiO2 Blast Furnace Slag System at 1823 K

In this study, CaO-SiO2-Al2O3-MgO-TiO2 slag was used as the research object to simulate the blast furnace ironmaking process. Based on the experimental data, the influences of basicity (R(w(CaO)/w(SiO2))) and the magnesia–alumina ratio (w(MgO)/w(Al2O3)) on desulfurization ability are discussed. Additionally, the influences of dissimilarity, basicity, and the magnesia–alumina ratio on slag structure were analyzed using Fourier transform infrared spectroscopy (FT-IR). The results show that when w(Al2O3) = 20% and w(MgO)/w(Al2O3) = 0.50, sulfide capacity (lgCs) accretion with the increment in R. Moreover, when w(Al2O3) = 20% and R = 1.30, sulfide capacity accretion with the increment in w(MgO)/w(Al2O3). Fourier transform infrared spectroscopy was used to confirm that, with increasing basicity and the magnesia–alumina ratio, the concentration of dissociated free oxygen ions (O2−) in slag increases, and these ions interact with the bridging oxygen (O0) of silicate to depolymerize the complex Si-O structure into simpler units.