New Smelting Process for Titanium: Magnesiothermic Reduction of TiCl4 into Liquid Bi and Subsequent Refining by Vacuum Distillation

We demonstrate a new continuous smelting process for Ti that combines magnesiothermic reduction of TiCl4 into liquid Bi and refining by vacuum distillation. TiCl4 is reduced by Mg into liquid Bi to form Bi-Ti liquid alloys, and subsequently refined by vacuum distillation. The Bi-Ti liquid alloys can be easily transferred from a reduction vessel to a refining vessel; consequently, the reduction and refining steps can be performed continuously. Bi-Ti alloys with various compositions were confirmed to form, and the compositions were controllable via adjustment of the nominal composition of TiCl4, Mg, and Bi. After reduction, the alloys were efficiently separated from MgCl2 by differences in their densities. In addition, vacuum distillation of the alloys purified Ti to be greater than 99.6 at pct. Moreover, consideration of the heat balance in the reduction step indicated that the proposed process has the potential to unlimitedly improve the feed rate of TiCl4 when the concentration of Ti in the alloy is 6 to 7 at pct.