A new reduction process is presented where TiO2 is used as the raw material for
reduction. It consists of the calcium reduction in the molten CaCl2 bath and the
electrochemical reaction for recovery of Ca from CaO in the same bath. TiO2
powder injected near the cathode reacts with a few mol percent Ca dissolved in
the melt. The by-product CaO of calciothermic reduction dissolves into the
molten CaCl2, and it is electrochemically decomposed into Ca and CO/CO2 gas by
giving the voltage higher than that of theoretical decomposition for pure CaO.
Some experimental results confirmed this process proposal, and the sufficiently
deoxidized titanium metal was obtained at the bottom of the cell, when the
basket type cathode was applied. Because the molten CaCl2 has a large solubility
for CaO, both mechanisms of the halide flux deoxidation and the electrochemical
deoxidation worked efficiently to remove oxygen in Ti, once the metallic Ti
particles were precipitated. This mechanism based on the calciothermic reduction
and the electrolysis of CaO was experimentally approved in comparison with FFC
process.