Electrochemical Behavior of Fe2O3 in Electro-Deoxygenation in NaCl–CaCl2 Molten Salt System

Abstract

In the NaCl–CaCl2 molten salt, a solid agglomerate of Fe2O3 particles is used as a raw material, and a graphite rod is used as an anode. At 800 °C, the composition and morphology of the product obtained by cyclic voltammetry and combined with constant cell pressure electrolysis at different times were analyzed by XRD and SEM to obtain the reduction mechanism of solid Fe2O3. (1) chemical formation of Ca2Fe2O5; (2) Ca2Fe2O5 was electrochemically reduced to metallic iron Ca2Fe2O5 → Fe3O4 → FeO → Fe, and finally electrolyzed for 5 h at a battery voltage of 2.5 V to prepare metal iron with an oxygen content of 1.29%. The electrolysis efficiency was 97.6%. The electrolysis product iron appears as interconnected micron-sized network particles. These studies provide theoretical support for the direct electroreduction of Fe2O3 particles to prepare metallic iron.