Reaction Behavior of SiC with CaO–SiO₂–Al₂O₃ Slag

Abstract

During the production process of ferrosilicon (FeSi), ferrosilicochrome (FeSiCr) and silicomanganese ferroalloy (SiMn), silicon carbide (SiC) particles are inevitably formed and distribute in the slags. The existence of SiC particles leads to a large difficulty for slag-metal separation and thus a great increase of metal loss. In this paper, the reaction behavior between SiC and CaO–SiO₂–Al₂O₃ slag is investigated in detail. It is of great guiding significance for adjusting the slags for the well separation of slag and metal in the production process of silicon-based ferroalloys. The reaction kinetics between SiC and CaO–SiO₂–Al₂O₃ slag depends significantly on the composition of slag, temperature and the particle size of SiC. Within a certain time, the reaction extent first decreases and then increases with the increase of the CaO/SiO₂ binary basicity, but gradually decreases by adding Al₂O₃ into the slag. Meanwhile, the increase of temperature promotes the solid-liquid reaction between SiC and CaO–SiO₂–Al₂O₃ slag.