Aluminium dissolved in cryolite-alumina melts migrates in the direction of the positive pole by passage of current . By a modified moving boundary technique the dissolved metal was found to separate into two zones with different mobilities . For the cryolite composition at 11100°C the apparent mobil
Electrochemical study of dissolved aluminium in molten NaFAlF3Al2O3
✍ Scribed by E.Y.L. Sum; M. Skyllas-Kazacos
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 908 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
The oxidation of dissolved metal in acidic cryolite melts has been studied at tungsten, classy carbon and graphite electrodes using the techniques of cyclic voltammetry and chronopotentiometry. The reaction was found to be diffusion controlled and quasi-reversible with n = 2, suggesting that monovalent aluminium is the main dissolved species in acidic melts. A value of C,,, Diz = 5.1 x lo-' mol cme2 stn was obtained in an alumina saturated melt at 977°C in the absence of a metal pad, while in the presence of an aluminium pad C,Dt/2 is of the order of 10-6molcm-2 s"* suggesting that other species such as dispersed metallic aluminium are also involved.
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