Calciothermic reduction of NiO by molten salt electrolysis of CaO in CaCl_2 melt

摘要

Metallic nickel powders with low and uniform residual oxygen content were produced from NiO using the molten salt electrolysis of CaO in CaCl_2 melt. Suitable amount of CaO for the reduction was in the range of 0.5-3.0 mol% CaO. The electrical isolation of NiO from both electrodes could produce metallic Ni in CaCl_2 melt. Separating the metal oxides from the cathode confirmed the mechanism of calciothermic reduction that the electrolysis of dissolved CaO in CaCl_2 melt produces Ca, and that the dissolved Ca in molten CaCl_2 successfully reduces NiO to metallic Ni. An average of about 600 ppm oxygen in Ni sample was achieved directly from oxide, when NiO was detached from the cathode.