Abstract
Modern aluminum reduction plants with large prebake reduction cells use essentially the same electrolyte chemistry, a low ratio bath containing 10 to 12 wt.% excess AlF3. Production results from modern reduction plants demonstrate that operating with low ratio bath contributes to a higher current efficiency, typically from 94 to 96%. Lithium is used as a bath additive to improve the performance, primarily in older cells, by increasing the electrical conductivity of the molten cryolitic bath and decreasing the bath operating temperature. Plant operational results were obtained using a combined lithium-modified low ratio (LMLR) bath in modern 180 kA prebake cells. The addition of lithium within a specific composition range was found to be beneficial in decreasing the cell voltage and unit energy consumption, and resulted in a significant improvement in the cell voltage stability. However, a decrease in current efficiencies was found to occur with the increase in LiF concentration, apparently as a consequence of the corresponding decrease in AlF3 content. The impact of the combined LMLR bath composition on electrolyte properties and cell performance is discussed.
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© 2016 The Minerals, Metals & Materials Society
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Tabereaux, A.T., Alcorn, T.R., Trembley, L. (2016). Lithium-Modified Low Ratio Electrolyte Chemistry for Improved Performance in Modern Reduction Cells. In: Bearne, G., Dupuis, M., Tarcy, G. (eds) Essential Readings in Light Metals. Springer, Cham. https://doi.org/10.1007/978-3-319-48156-2_11
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DOI: https://doi.org/10.1007/978-3-319-48156-2_11
Publisher Name: Springer, Cham
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