The Electrolytic Reduction of MoO3 in CaCl2-NaCl Molten Salt

Abstract

Electro-deoxidation reduction technology is a very attractive method used to treat oxides in metallurgical industry. In this paper, cyclic voltammetry, square wave voltammetry and open circuit chronopotentiometry were applied to study the electrochemical behavior of MoO3 cathode in the CaCl2-NaCl melt at 873 K. Through the electrolytic reduction of MoO3 at different potentials (−1.15 V, −1.45 V and −1.75 V, vs Ag/AgCl) and XRD analysis, MoO3 was found to be transformed into several intermediate compounds (CaMoO4, MoO2 and Na1.4Mo2O4) and finally reduced to metallic Mo. When the electrolysis time was increased from 3 to 18.5 h and the employed potential was reduced from −1.75 V to −2.30 V (vs Ag/AgCl), the intermediate compounds could be completely reduced to metallic Mo, and the reduction ratio of MoO3 was calculated to be 93.7%.