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Electrolysis expansion performance of semigraphitic cathode in [K3AlF6/Na3AlF6]-AlF3-Al2O3 bath system

  • Jie Li (李劼)
  • Zhao Fang (方钊)
  • Yan-qing Lai (赖延清)
  • Xiao-jun Lü (吕晓军)Email author
  • Zhong-liang Tian (田忠良)
Article

Abstract

The electrolysis expansion of semigraphitic cathode in [K3AlF6/Na3AlF6]-AlF3-Al2O3 bath system was tested by self-made modified Rapoport apparatus. A mathematical model was introduced to discuss the effects of αCR (cryolite ratio) and βKR (elpasolite content divided by the total amount of elpasolite and sodium cryolite) on performance of cathode electrolysis expansion. The results show that K and Na (potassium and sodium) penetrate into the cathode together and have an obvious influence on the performance of cathode electrolysis expansion. The electrolysis expansion and K/Na penetration rate increase with the increase of αCR. When αCR=1.9 and βKR=0.5, the electrolysis expansion is the highest, which is 3.95%; and when αCR=1.4 and βKR=0.1, the electrolysis expansion is the lowest, which is 1.28%. But the effect of βKR is correlative with αCR. When αCR=1.6 and 1.9, with the increase of βKR, the electrolysis expansion and K/Na penetration rate increase. However, when αCR=1.4, the electrolysis expansion and K/Na penetration rate firstly increase and then decrease with the increase of βKR.

Key words

aluminum electrolysis semigraphitic cathode low temperature electrolysis electrolysis expansion K penetration Na penetration 

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Copyright information

© Central South University Press and Springer-Verlag GmbH 2009

Authors and Affiliations

  • Jie Li (李劼)
    • 1
  • Zhao Fang (方钊)
    • 1
  • Yan-qing Lai (赖延清)
    • 1
  • Xiao-jun Lü (吕晓军)
    • 1
    Email author
  • Zhong-liang Tian (田忠良)
    • 1
  1. 1.School of Metallurgical Science and EngineeringCentral South UniversityChangshaChina

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