Study on the mechanism of preparing metallic iron from soluble anode

• Published in: Electrochemistry communications 2023-08, Vol.153, p.107541, Article 107541
• Main Authors: Li, Hui, Chen, Geng, Liang, Jinglong, Cai, Zongying, Yang, Yu
• Format: Article
• Language: English
• Subjects: Electrolytic deposition; Metallic iron; Reduction mechanism; Soluble anode
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2023.107541

•Determining the sintering conditions for preparation of high-performance anodes.•Investigate mechanisms of anode dissolution and cathode deposition in electrolysis.•The electrolysis product is dendritic metallic iron with a purity of 99.5%.•Soluble anode electrolysis is a short process and adaptable to raw materials. The optimization of the ironmaking process for the preparation of high-purity metallic iron has become an important part of the production of the iron and steel industry due to the increasing demand for steel in the modern industry. This article adopted the soluble anode molten salt electrolysis process to prepare a soluble anode with excellent conductivity by mixing Fe2O3 and C in a molar ratio of 1:3, sintering at 1073 K for 6 h. The metal iron was electrolytically deposited on the cathode by applying a constant current of 0.1 A for 6 h in the NaCl-CaCl2 molten salt system. The anode dissolution and cathode deposition mechanisms were analyzed based on the electrolysis U-t curve. The experimental results showed that the presence of C after sintering reduces the impedance value by reducing Fe2O3 to Fe3O4. During the electrolysis process, Fe2+ in Fe3O4 oxidized to Fe3+ and entered the molten salt, migrated to the vicinity of the cathode, and underwent the reduction process of Fe3+-Fe2+-Fe during the cathodic reduction process. The deposited Fe on the cathode exhibited a dendritic crystal structure with a purity of 99.51%.