Electrolysis of CaO in the Molten CaCl_2 for Direct Reduction of TiO_2

摘要

Electrochemical behavior of CaO-CaCl_2 melt was studied from several experimental approaches to promote OS process,i. e., the calciothermic reduction of the titanium oxide with electrolysis of CaO dissolved in the molten CaCl_2. The predicted existence of Ca concentrated region near the cathode was experimentally confirmed both by the reduction under electrical isolation and by wet chemical analysis of the solidified salts. It is deduced from the electrode-shielding methods that the total rate of CaO electrolysis is controlled by O~(2-) transportation in the CaCl_2-CaO melt. In CaTiO_3 reduction,however, the oxygen diffusion in the formed Ti layer and the anodic surface area is rate-determing factors. The oxygen absorbing anode based on LaGaO_3 ionic conductor could pomp up the oxygen gas from the CaCl_2 melt.