Cristin-resultat-ID: 917366
Sist endret: 5. februar 2014, 10:47
NVI-rapporteringsår: 2012
Resultat
Vitenskapelig artikkel
2012

Concentration Gradients of Individual Anion Species in the Cathode Boundary Layer of Aluminium Reduction Cells

Bidragsytere:
  • Asbjørn Solheim

Tidsskrift

Light Metals
ISSN 0147-0809
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2012
Sider: 665 - 670

Importkilder

Isi-ID: 000324538600114

Beskrivelse Beskrivelse

Tittel

Concentration Gradients of Individual Anion Species in the Cathode Boundary Layer of Aluminium Reduction Cells

Sammendrag

It is well known that the system NaF-AlF3, which constitutes the “backbone” of the electrolyte used in primary aluminium manufacture, forms Na+, F-, and a number of fluoro-aluminate anion complexes in the molten state. Since mainly the Na+ ion carries electric current, the aluminium-containing complexes must diffuse towards the cathode, resulting in concentration gradients in the cathode boundary layer. Starting from a structural model for the melt containing five anion species, it was possible to calculate the concentration gradients of the individual ions using the Stefan-Maxwell equation for diffusion in a multi-component system. Generally, AlF4- and Al2F7- were transported towards the cathode, while F- and AlF63- moved away from the cathode. For NaF/AlF3 molar ratios higher than 2.0, AlF52- moved towards the cathode, while it diffused away from the cathode in more acid melts.

Bidragsytere

Asbjørn Solheim

  • Tilknyttet:
    Forfatter
    ved SINTEF Industri ved SINTEF AS
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