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Sideledge in Aluminium Cells: Further Considerations Concerning the Trench at the Metal-Bath Boundary

  • Asbjørn SolheimEmail author
  • Eirik Hjertenæs
  • Kati Tschöpe
  • Marian Kucharik
  • Nancy Jorunn Holt
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

It is known that the sideledge in aluminium cells is thinner than elsewhere at the level of the metal-bath interface. The present paper discusses three possible mechanisms for this local thinning or “trench” formation. These are: (i) High local heat transfer coefficient related to waves at the metal-bath interface, (ii) High local overall heat transfer coefficient between metal and ledge related to the geometry of the lower part of the metal-bath meniscus, and (iii) Mixing of bulk bath and a bath film containing alumina particles at the metal-bath meniscus region, leading to high local superheat. Analyses of the lower part of the ledge revealed that the ledge contained substantial amounts of alumina, and it was shown by calculation that alumina particles can be lifted by the bath film between the metal and the ledge. The three explanations for trench formation do not exclude each other.

Keywords

Sideledge Trench Bath film Heat transfer 

Notes

Acknowledgements

The present work was supported by the project “Superior Technology for Energy Efficient Aluminium Production” (STEP), financed by Hydro Aluminium and the Research Council of Norway. Permission to publish the results is gratefully acknowledged.

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Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • Asbjørn Solheim
    • 1
    Email author
  • Eirik Hjertenæs
    • 2
  • Kati Tschöpe
    • 2
  • Marian Kucharik
    • 2
  • Nancy Jorunn Holt
    • 2
  1. 1.SINTEFTrondheimNorway
  2. 2.Hydro AluminiumØvre ÅrdalNorway

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