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Silver as anode in cryolite—alumina-based melts
Kucharík, M., Chamelot, P., Cassayre, L. and Taxil, P. Silver as anode in cryolite—alumina-based melts Chemical Papers, Vol.61, No. 2, 2007, 142-145
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Document type:
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Článok z časopisu / Journal Article |
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Collection:
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Chemical papers
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| Author(s) |
Kucharík, M.
Chamelot, P.
Cassayre, L.
Taxil, P.
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| Title |
Silver as anode in cryolite—alumina-based melts
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| Journal name |
Chemical Papers
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| Publication date |
2007
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| Year available |
2007
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| Volume number |
61
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| Issue number |
2
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| ISSN |
0366-6352
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| Start page |
142
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| End page |
145
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| Place of publication |
Poland
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| Publisher |
Versita
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| Collection year |
2007
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| Language |
english
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| Subject |
250000 Chemical Sciences
250200 Inorganic Chemistry
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| Abstract/Summary |
The anodic behaviour of silver was investigated in cryolite—alumina-based melt. Silver has a lower melting point (ca. 960°C) than the other metals considered as possible inert materials for aluminium electrolysis. The working temperature used in aluminium industry is approximately 960°C, depending on the melt composition. Therefore, the stability of silver during the anodic process was tested at 870°C in an acidic electrolyte consisting of 65.5 mass % Na3AlF6 + 22.9 mass % AlF3 + 5.7 mass % CaF2 + 3.9 mass % LiF + 2 mass % Al2O3 with the melting point ca. 850°C. The electrolyte without alumina was prepared as well, with the melting point ca. 860°C. The resulting cryolite ratio (CR = n(NaF)/n(AlF3)) for both electrolytes was equal to 1.6. The behaviour of the silver anode was studied by voltammetry measurements. The electrochemical study showed that an oxidation reaction occurred at a potential below the oxygen evolution potential. Silver was not found to be stable under oxygen evolution. The degradation of the silver anode was apparent after electrolysis.
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