Calciothermic reduction of TiO2 and in situ electrolysis of CaO in the molten CaCl2

A new cell concept for calciothermic reduction is presented where TiO2 is used as the raw material for reduction. The reduction system consists of a single cell, where both the reduction reaction and the electrolytic reaction for recovery of reducing agent coexist in the same molten CaCl2 bath. TiO2 powder reacts with a few mol%Ca dissolved in the melt. Sufficiently deoxidized titanium metal was obtained at the bottom of the cell. Because the molten CaCl2 has a large solubility for CaO, both mechanisms of the halide flux deoxidation and the electrochemical deoxidation work efficiently once the metallic Ti was precipitated. The reducing agent is in situ recovered by electrolysis of CaO as, At the anode : C + 2 O-2- = CO2 + 4 e(-) At the cathode : Ca2+ + 2e(-) = Ca. Some experimental results are presented for confirmation of this proposal and mechanism. (c) 2004 Elsevier Ltd. All rights reserved.