Effect of Fe₂O₃ on Electro-Deoxidation in Fe₂O₃-Al₂O₃-NaCl-KCl System

Abstract

The reduction of Fe2O3-Al2O3 is one of the important reactions in the resource utilization of iron-containing oxide waste. Fe2O3-Al2O3 was electro-deoxidized in the NaCl-KCl system by molten salt electrolysis to prepare FeO/Al2O3. The effect of the Fe2O3 content on the electro-deoxidation reaction process was studied. The results show that under the conditions of 850 °C, 2.3 V, and electro-deoxidation for 4 h, FeO/Al2O3 could be obtained by controlling the content of Fe2O3. The deoxidation process was divided into three stages: electric double layer charging, Fe2O3 electro-deoxidation to Fe3O4, and Fe3O4 electro-deoxidation to FeO. With the increase in the Fe2O3 content, the deoxidation reaction rate increased, and the low-valence iron oxide particles obtained by electro-deoxidation became larger. The mechanism of the influence of Fe2O3 on the electro-deoxygenation process was determined by analyzing the experimental results. The increase in the Fe2O3 content increased the concentration of activated molecules in the system, while it reduced the resistance of electro-deoxidation. The migration of active particles in the cathode was smoother, which increased the percentage of deoxygenation of activated molecules, thereby shortening the process of the deoxidation reaction.

Keywords

• molten salt electrolysis
• Fe₂O₃-Al₂O₃-NaCl-KCl system
• FeO/Al₂O₃
• Fe₂O₃ influence mechanism