Interactions of molten salts with cathode products in the FFC Cambridge Process

Chen, George Z.

Abstract

© 2020, University of Science and Technology Beijing and Springer-Verlag GmbH Germany, part of Springer Nature. Molten salts play multiple important roles in the electrolysis of solid metal compounds, particularly oxides and sulfides, for the extraction of metals or alloys. Some of these roles are positive in assisting the extraction of metals, such as dissolving the oxide or sulfide anions, and transporting them to the anode for discharging, and offering the high temperature to lower the kinetic barrier to break the metal-oxygen or metal-sulfur bond. However, molten salts also have unfavorable effects, including electronic conductivity and significant capability of dissolving oxygen and carbon dioxide gases. In addition, although molten salts are relatively simple in terms of composition, physical properties, and decomposition reactions at inert electrodes, in comparison with aqueous electrolytes, the high temperatures of molten salts may promote unwanted electrode-electrolyte interactions. This article reviews briefly and selectively the research and development of the Fray-Farthing-Chen (FFC) Cambridge Process in the past two decades, focusing on observations, understanding, and solutions of various interactions between molten salts and cathodes at different reduction states, including perovskitization, non-wetting of molten salts on pure metals, carbon contamination of products, formation of oxychlorides and calcium intermetallic compounds, and oxygen transfer from the air to the cathode product mediated by oxide anions in the molten salt.

Citation

Chen, G. Z. (2020). Interactions of molten salts with cathode products in the FFC Cambridge Process. International Journal of Minerals, Metallurgy and Materials, 27(12), 1572-1587. https://doi.org/10.1007/s12613-020-2202-1

• Journal Article Type: Article
• Acceptance Date: Sep 30, 2020
• Online Publication Date: Dec 30, 2020
• Publication Date: 2020-12
• Deposit Date: Oct 12, 2020
• Publicly Available Date: Dec 31, 2021
• Journal: International Journal of Minerals, Metallurgy and Materials
• Print ISSN: 1674-4799
• Electronic ISSN: 1869-103X
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 27
• Issue: 12
• Pages: 1572-1587
• DOI: https://doi.org/10.1007/s12613-020-2202-1
• Keywords: FFC Cambridge Process; molten salts; electrolysis; extraction; oxides; sulfides; metals; alloys; reaction mechanisms
• Public URL: https://nottingham-repository.worktribe.com/output/4958854
• Publisher URL: https://link.springer.com/article/10.1007%2Fs12613-020-2202-1
• Additional Information: Received: 14 July 2020; Revised: 22 September 2020; Accepted: 30 September 2020; First Online: 30 December 2020; Change Date: 11 March 2021; Change Type: Erratum; Change Details: An Erratum to this paper has been published:; Change Details: https://doi.org/10.1007/s12613-021-2271-9