A Novel Method for Preparing Si–Ti Alloy by Co-Reduction of Silicon Slag and Ti-Bearing Blast Furnace Slag

Silicon slag (SS) and Ti-bearing blast furnace slag (TBFS) are large-scale waste slags produced in the metallurgical industry that contain rich Si and Ti resources. In this paper, an innovative process is proposed to produce Si–Ti alloy by the co-reduction of SS and TBFS to achieve simultaneous treatment of both waste slags. Si in SS was used as reducing agent to reduce TiO2 in TBFS to produce Si–Ti alloy. The possibility of Si reduction of TiO2 was determined by thermodynamic calculation, and the experimental results indicated that the key to the reaction process lies in the decrease in activity of SiO2 in slag. The slag viscosity can be reduced by adding CaO, which can enhance the enrichment effect of the alloy. The Si–Ti alloy was successfully prepared by the co-reduction experiment of these two waste slags. Additionally, an investigation of the mechanism of SS and TBFS co-reduction was conducted. The proposed process is simple, environmentally friendly, and provides a novel and clean way for the effective utilization of SS and TBFS.