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Metallurgical and Materials Transactions B

, Volume 50, Issue 1, pp 416–428 | Cite as

Experimental Investigation of the Impact of Cathode Grade on Sludge Formation at the Cathode Block-Aluminum Interface of Hall–Héroult Cells

  • Jean-René Landry
  • Mojtaba Fallah Fini
  • Gervais SoucyEmail author
  • Martin Désilets
  • Patrick Pelletier
  • Loig Rivoaland
  • Didier Lombard
Article
  • 49 Downloads

Abstract

The presence of resistive sludge on the cathode surface in Hall–Héroult cells can increase the aluminum production costs and reduces cell lifetime. Modern cells with graphitized cathode blocks generally operate satisfactorily but some are exhibiting excessive deposit formation, thus lower performances. Little attention has ever been given to the role of the cathode grade and its properties on sludge formation. In this investigation, five graphitized industrial cathode grades with varying properties are tested on a bench scale aluminum electrolysis setup with cathodic current density of 0.9 A/cm2, under a nitrogen atmosphere at 1233 K (960 °C) for 8 hours with initial bath composition of 10 pct alumina, cryolite ratio of 2.2, 5 pct CaF2 and no point feeding. Postmortem characterization includes Rietveld refinement of deposits, optical microscopy and SEM-EDS observations of the carbon-aluminum interface. Sludge located near the center of the cathode surface was generated during the experiments despite the absence of point feeding. The sludge profile was variable among grades and could be related to the horizontal and vertical thermal conductivities of the blocks. This study has pushed further the understanding of the mechanisms of sludge formation and dissolution concerning the cathode grade properties.

References

  1. 1.
    X. Liao and H.A. Oye: Light Met. 1999, Proceedings of the International Symposium, 1999, pp. 621–27.Google Scholar
  2. 2.
    F. Allard, G. Soucy and L. Rivoaland: Metall. Mater. Trans. B, 2014, vol. 45B, pp. 2475-2485.CrossRefGoogle Scholar
  3. 3.
    K. Grjotheim, and H. Kvande, eds., Introduction to Aluminium Electrolysis - Understanding the Hall-Heroult Process, 2nd ed., Aluminium-Verlag, Düsseldorf, Germany, 1993.Google Scholar
  4. 4.
    Y. Song, J. Peng, Y. Di, Y. Wang, and N. Feng: Can. Metall. Q., 2017, vol. 57. Ahead of Print.Google Scholar
  5. 5.
    M. Sorlie and H. A. Oye: Cathodes in Aluminium Electrolysis, 3rd ed., Aluminium-Verlag, Düsseldorf, Germany, 2010.Google Scholar
  6. 6.
    T. Utigard and J. M. Toguri: Light Met. 1991, Proceedings of the International Symposium, 1991, pp. 273–81.Google Scholar
  7. 7.
    F. Allard, G. Soucy, L. Rivoaland and M. Désilets: Journal of Thermal Analysis and Calorimetry, 2014, vol. 119, pp. 1303-1314.CrossRefGoogle Scholar
  8. 8.
    P.Y. Geay, B.J. Welch, and P. Homsi: Light Met. 2001, Proceedings of the International Symposium, 2001, pp. 541–47.Google Scholar
  9. 9.
    M. Fallah Fini, G. Soucy, M. Désilets, P. Pelletier, D. Lombard, and L. Rivoaland: Alumina, Aluminum, Proceedings of the International Symposium on ICSOBA, 2017, vol. 42, pp. 987–96.Google Scholar
  10. 10.
    T. Li, S. T. Johansen, and A. Solheim: TMS Light Met., 2015, pp. 831–36.Google Scholar
  11. 11.
    T. Utigard: Light Met. 1999, Proceedings of the International Symposium, 1999, pp. 319–26.Google Scholar
  12. 12.
    X. Liao and H.A. Oye: Light Met. 1998, Proceedings of the International Symposium, 1998, pp. 667–74.Google Scholar
  13. 13.
    B. Novak, K. Tschöpe, A.P. Ratvik, and T. Grande: Light Met. 2012, Proceedings of the International Symposium, 2012, pp. 1343–48.Google Scholar
  14. 14.
    A. Zoukel, P. Chartrand, and G. Soucy: Light Met. 2009, Proceedings of the International Symposium, 2009, pp. 1123–28.Google Scholar
  15. 15.
    B. Novak, A.P. Ratvik, Z. Wang, and T. Grande: Light Met. 2018, Proceedings of the International Symposium, 2018, pp. 1215–22.Google Scholar
  16. 16.
    M. A. Coulombe, G. Soucy, L. Rivoaland and L. Davis: Metall. Mater. Trans. B, 2016, vol. 47, pp. 1280-1295.CrossRefGoogle Scholar
  17. 17.
    K. Kalgraf and K. Torklep: Light Met. 1998, Proceedings of the International Symposium, 1998, pp. 455–64.Google Scholar
  18. 18.
    Z. Wang, S. Nobakhtghalati, A. Store, A. Solheim, K. Tschöpe, A.P. Ratvik, and T. Grande: Light Met. 2016, Proceedings of the International Symposium, 2016, pp. 895–902.Google Scholar
  19. 19.
    K. Tschöpe, A. Store, S. Rorvik, A. Solheim, E. Skybakmoen, T. Grande, and A.P. Ratvik: Light Met. 2012, Proceedings of the International Symposium, 2012, pp. 1349–54.Google Scholar
  20. 20.
    K. Tschöpe, A. Store, E. Skybakmoen, A. Solheim, T. Grande, and A.P. Ratvik: Light Met. 2013, Proceedings of the International Symposium, 2013, pp. 1251–56.Google Scholar
  21. 21.
    E. Skybakmoen, S. Roervik, A. Solheim, K.R. Holm, P. Tiefenbach, and O. Ostrem: Light Met. 2011, Proceedings of the International Symposium, 2011, pp. 1059–66.Google Scholar
  22. 22.
    J.-M. Dreyfus and L. Joncourt, in Light Metals 1999, C.E. Eckert, ed., The Minerals, Metals and Materials Society (TMS), Warrendale, PA, 1999, pp. 199–206.Google Scholar
  23. 23.
    L. Rivoaland: Bauxite, Alumina, Alum., Proceedings of the International Symposium on ICSOBA, 2016.Google Scholar
  24. 24.
    F.R. Feret: Light Met. 2008, Proceedings of the International Symposium, 2008, pp. 118–28.Google Scholar
  25. 25.
    F. Allard, M.A. Coulombe, G. Soucy, and L. Rivoaland: Light Met. 2014, Proceedings of the International Symposium, 2014, pp. 1233–38.Google Scholar
  26. 26.
    J.-R. Landry, M. Fallah Fini, G. Soucy, M. Désilets, P. Pelletier, L. Rivoaland, and D. Lombard: Light Met. 2018, Proceedings of the International Symposium, 2018, pp. 1229–33.Google Scholar
  27. 27.
    A. Yurkov: Refractories for Aluminium Electrolysis and the Cast House, 1st ed., Springer, Switzerland, 2015.Google Scholar
  28. 28.
    M. Brassard, M. Soucy, M. Désilets and D. Lombard: Can. Metall. Q., 2016, vol. 55, pp. 356-364.CrossRefGoogle Scholar
  29. 29.
    M. Korenko: J. Chem. Eng. Data, 2008, vol. 53, pp. 794-797.CrossRefGoogle Scholar
  30. 30.
    E. W. Dewing and P. Desclaux: Metall. Mater. Trans. B, 1977, vol. 4, pp. 555-561.CrossRefGoogle Scholar
  31. 31.
    Z. Wang, E. Skybakmoen, and T. Grande: Light Met. 2009, Proceedings of the International Symposium, 2009, pp. 353–58.Google Scholar
  32. 32.
    J. Thonstad, G. Felnner, G. M. Haarberg, J. Hives and H. Kvande: Aluminium Electrolysis - Fundamentals of the Hall–Héroult Process, 3rd ed., Aluminium-Verlag, Düsseldorf, Germany, 2001.Google Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2018

Authors and Affiliations

  • Jean-René Landry
    • 1
  • Mojtaba Fallah Fini
    • 1
  • Gervais Soucy
    • 1
    Email author
  • Martin Désilets
    • 1
  • Patrick Pelletier
    • 2
  • Loig Rivoaland
    • 3
  • Didier Lombard
    • 4
  1. 1.Université de SherbrookeSherbrookeCanada
  2. 2.Rio TintoJonquièreCanada
  3. 3.Carbone SavoieAigueblanche CedexFrance
  4. 4.Rio Tinto, LRF, rue Henri Sainte Claire Deville – CS 40114Saint Jean de MaurienneFrance

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