Study on preparation of silicon vanadium alloy by direct smelting of corundum slag with low vanadium content

Corundum slag is a solid waste produced in smelting 50 or 80 vanadium iron by thermite process. In order to improve the utilization value of corundum slag, the primary raw materials in this investigation were corundum slag, ferrosilicate, limestone, calcium carbide and sodium carbonate, respectively. Moreover, the silicon-vanadium alloy was prepared by electric furnace smelting. Limestone was selected as a slag-forming agent to investigate the effect of the addition amount of limestone on the slag phase and the yield of vanadium. The results show that the recovery rate of vanadium can reach 96.5% when the content of CaO in the final slag is 22%. The yield of vanadium increases to the maximum of 96.2% when the silicon blending coefficient increases to 105% under ferrosilicon are selected as reducing agent condition. Moreover, the dephosphorization rate increases to the maximum of 72% when the addition amount of CaC₂ reaches 3.5% under calcium carbide is selected as a dephosphorization agent condition. In addition, the desulfurization rate increases from 70% to 86% when the CaO content in the slag increases from 16% to 22% by using CaO+2%Na₂CO₃.