A Review: Understanding the Science and the Impacts of Impurities upon the Electrolytic Bath of Hall–Héroult Reduction Cells


The aim of this article is to present an overview of impurities of alkali metals and alkaline earth elements included in smelter-grade alumina and other raw materials that primarily report to the electrolyte, i.e., bath, and to suggest pathways for improved control at primary aluminum smelters. Comments are included on how these impurities affect intermediate subprocesses, metal products, and cell condition. The authors have worked to create a reference that not only reports on the scientific aspects of how impurities react in a bath of molten salt under electrolysis but also covers the practical matters of concern regarding impurities that affect the electrolyte. By combining scientific knowledge with process engineering techniques, readers should be able to better manage impurities and related impacts in aluminum production processes.

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We thank Nik Winjum and Les Edwards for their support in the preparation of this article. We are also grateful to Merino, Margarita R. (Ph.D. – Florida State University) for her encouragement, dedication, and support.

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Lindsay, S.J., Welch, B.J. A Review: Understanding the Science and the Impacts of Impurities upon the Electrolytic Bath of Hall–Héroult Reduction Cells. JOM (2021). https://doi.org/10.1007/s11837-021-04572-7

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