Current Efficiency in Prebake and Søderberg Cells
An isotope dilution technique was used to study 24 h current efficiencies in 22 semi-randomly selected prebake pots and 21 randomly selected Søderberg pots at the Elkem smelters. A total of 110 measurements were made and compared with the 1128 current efficiency measurements made on Alcoa prebake pots using Alcoa’s silver dilution technique. Results are discussed with emphasis on similarities and dissimilarities in prebake and Søderberg pots. Some theoretical proposals are made regarding the similarities and differences.
Results for the prebake pots confirm the basic conclusions from the Alcoa studies including the relative importance of bath chemistry compared to noise (instability) and the impact of low alumina operation on current efficiency. Measurements of 24 h current efficiencies for Søderberg pots are scarce to non-existent. Only temperature and aluminium fluoride have similar influences in the two pot technologies.
KeywordsCurrent efficiency Soderberg Prebake
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- 1).T. B. Pedersen, Light Metals, 2001, 489–495.Google Scholar
- 2).G. P. Tarcy and D. R. DeCapite, Light Metals, (1990) 275–283.Google Scholar
- 3).B. Berge, K. Grjotheim, C. Krohn, R. Naeumann and K. Tørklep, Light Metals, 1975, 37–47.Google Scholar
- 6).G. L. Fredrickson, Light Metals, 2003, 299–314Google Scholar
- 7).X. Wang, R. D. Peterson and N. Richards, Light Metals, 1991, 323–330.Google Scholar
- 8).A. Solheim, S. Rolseth, E. Skybakmoen, L. Støen, Å. Sterten, and T. Store, Light Metals, 1995, 451–460.Google Scholar
- 9).H. Kvande, Light Metals, 1989, 261–268.Google Scholar
- 10).R. A. Lewis, J. Metals, vol 19, 1967, 30–36.Google Scholar
- 12).M. J. Leroy, T. Pelekis and J.-M. Jolas, Light Metals, 1987, 291–294.Google Scholar
- 13).L. I. Kiss, S. Poncsak, Light Metals, 2002, 217–223Google Scholar
- 14).G. P. Tarcy and J. Sorenson, Light Metals, 1991, 453–459.Google Scholar
- 15).G. P. Tarcy, Proceedings of the Fifth Australasian Aluminium Smelter Workshop, 1995, 139Google Scholar
- 16).G. P. Tarcy, Proceedings of the Seventh Australasian Aluminium Smelter Workshop, 2001Google Scholar
- 17).G. P. Tarcy, TMS Industrial Aluminum Electrolysis, 2003, 12Google Scholar