Effect of Si on Desulfurization in Fe–Si–S, Fe–Si–Cr–S and Fe–Si–Ni–S Melts

The effect of silicon content varied from 0 to 45 mass% on the desulfurization in Fe–Si–S, Fe–Si–Cr–S, and Fe–Si–Ni–S melts was investigated at 1873 K (1600°C). It was found that sulfur can be remarkably removed when the silicon content is more than 30 mass%. From the thermodynamic analysis, it was concluded that sulfur may be primarily evaporated as SiS(g), and the activities of silicon and activity coefficient of sulfur in alloys will increase as increasing the silicon content, which makes the evaporation of SiS(g) more feasible and more sulfur removed.