Electrochemical Reduction Behavior of Soluble CaTiO₃in Na₃AlF₆-AlF₃Melt for the Preparation of Metal Titanium

Direct preparation of metal titanium from soluble CaTiO 3 in the Na 3 AlF 6 -AlF 3 melt by electrolysis was confirmed, providing a short route for the high value utilization of CaTiO 3 concentrates obtained from the titanium bearing blast furnace slag. The solubility of CaTiO 3 in the Na 3 AlF 6 -AlF 3 melt at 1253 K was determined by the isothermal saturation method and the electrochemical reduction behavior of TiO 3 2− was investigated by cyclic voltammogram, square wave voltammogram, open circuit potential and potentiostatic electrolysis. The results indicated that the solubility of CaTiO 3 in the melt was 2.4% at 1253 K. The TiO 3 2− ions were reduced to metal titanium by the consecutive three-step reduction reactions: TiO 3 2 − → TiO → Ti 2 O → Ti. The diffusion coefficient of TiO 3 2− in the Na 3 AlF 6 -AlF 3 melt was 6.7 × 10 −6 cm 2 s −1 at 1253 K. The deposited metal titanium was successfully separated with Na 3 AlF 6 by evaporation at 1823 K.