Abstract
There have been many studies investigating the effects of various parameters on the current efficiency in aluminium smelting cells. One of the most important and most widely debated of these parameters is alumina concentration, because of its implications in feed strategies and cell management. This paper presents the results from a study investigating the effects of alumina concentration, bath chemistry, current density and anode-cathode spacing on current efficiency. Gas emissions from a laboratory scale cell were measured by on-line mass spectrometry, current efficiency was determined by an oxygen balance method.
Electrolysis was performed from various starting alumina concentrations of 6 – 8 wt% until anode effect was reached. After initial start-up periods there was no variation in current efficiency as the alumina was depleted and anode effect approached.
Increasing the cryolite molar ratio, in agreement with other reports, has a strong negative effect on current efficiency. Results also show a strong increase in current efficiency with increasing current density. No effect of electrode spacing was detected.
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References
M.M.R. Dorreen, M.M. Hyland and B.J. Welch, “An Improved Method for Current Efficiency Determination in a Laboratory Aluminium Cell,” Light Metals 1997, 1189–1193.
B. Lillebuen and Th. Mellerud, “Current Efficiency and Alumina Concentration,” Light Metals 1985, 639–645.
K. Grjotheim, C. Krohn, M. Malinovský, K. Matiašovský and J. Thonstad, Aluminium Electrolysis, 2nd Edition, Aluminium Verlag, Dusseldorf, 1982, 344.
M.J. Leroy, T. Pelekis and J.M. Jolas, “Continuous Measurement of Current Efficiency, by Mass Spectrometry, on a 280 KA Prototype Cell,” Light Metals 1987, 291–294.
T.R Alcorn, C.J. McMinn and A.T. Tabereaux, “Current Efficiency in Aluminium Electrolysis by Anode gas Analysis,” Light Metals 1988, 683–695.
P.A. Solli, T. Haarberg, T. Eggen, E. Skybakmoen and A. Sterten, “A Laboratory Study of Current Efficiency in Cryolitic Melts,” Light Metals 1994, 195–203.
T.G. Pearson and J. Waddington, “Electrode Reactions in the Aluminium Reduction Cell,” Discussions Faraday Society, Vol. 1, 1947, 307–320.
H. Kvande, “Bath Chemistry and Aluminium Cell Performance — Facts, Fictions and Doubts,” JOM, vol.46, no. 11, 1994, 22–29.
B.J. Welch, “Electrochemical Production of Quality Aluminium,” Alumitech 1997, Proceedings, Vol.III, Aluminum Association USA, Atlanta, May 1997, 800–813.
B.A. Sadler, B.J. Welch and S. Hume, “Anode Consumption Mechanisms,” Fifth Australasian Aluminium Smelter Technology Workshop, 1995, 34–81.
C. Castellano, D. Bratland, K. Grjotheim, T. Müftüoglu and J. Thonstad, “Current Efficiency Measurements in Laboratory Aluminium Cells-IV. Depletion of Alumina and Cell Voltage,” Canadian Metallurgical Quarterly, vol. 18, 1979, 13–18.
E. Dewing, “Loss of Current Efficiency in Aluminium Electrolysis Cells,” Metallurgical Transactions B, vol.22B, 1991, 177–182.
R. Dorin, E.J. Frazer and A.M. Vecchio-Sadus, “Current Efficiency, Mass Transfer & Bubble Evolution Characteristics in a Laboratory-Scale Alumina Reduction Cell With Optional Sleeved Anode,” Light Metals 1994, 205–210.
K. Grjotheim, C. Krohn, M. Malinovsky, K. Matiasovsky and J. Thonstad, Aluminium Electrolysis, 2nd Edition, Aluminium Verlag, Dusseldorf, 1982, 340.
A. Silny and T.A. Utigard, “Determination of the Factors Which Control the CO/CO2 Ratio of the Anode Gas,” Light Metals 1995, 205–211.
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© 2016 The Minerals, Metals & Materials Society
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Dorreen, M.M.R., Hyland, M.M., Welch, B.J. (2016). Current Efficiency Studies in a Laboratory Aluminium Cell Using the Oxygen Balance Method. 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_29
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DOI: https://doi.org/10.1007/978-3-319-48156-2_29
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