Recovery of Ti-bearing blast furnace slag and diamond wire saw silicon powder waste by alloying and electromagnetic separation technique

Abstract

Ti-bearing blast furnace slag (TBFS) and diamond wire saw silicon powder (DWSSP) waste are solid wastes that have been investigated by researchers. In this paper, the possibility of metal thermal reduction of TBFS is determined by calculating the component activities using the molecular interaction volume model (MIVM). The metal thermal reduction and electromagnetic separation technique was used to simultaneously recover titanium (Ti) and silicon (Si) from waste. DWSSP and Al were used as the reducing agents for the high-temperature reduction of TBFS in an induction furnace. The reduced Ti was alloyed with a small amount of Al and residual Si in DWSSP. The alloy and slag were separated by electromagnetic stirring because they were subjected to forces in opposite directions. The effects of CaF2 addition and holding time on the recovery rate of Ti were studied. It was found that the addition of CaF2 to the raw materials improved the separation of the alloy from the slag. Si and TiSi2 were the main phases in the recovered alloy. This simple process provides a new method to recover Ti and Si from TBFS and DWSSP.