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 percent 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 + O2- = CO2 + 4 e
at the cathode : Ca2+ + 2 e = Ca.
Some experimental results are presented for confirmation of this proposal and
mechanism.