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›› 2011, Vol. 11 ›› Issue (5): 755-760.

• 反应与分离 • 上一篇    下一篇

含LiF和KF的电解质熔体对铝电解阴极的渗透过程

张跃宏 翟秀静 王耀武 彭建平 李斌川 冯乃祥   

  1. 东北大学材料与冶金学院 东北大学材料与冶金学院 东北大学材料与冶金学院 东北大学材料与冶金学院 东北大学材料与冶金学院 东北大学材料与冶金学院
  • 收稿日期:2011-07-21 修回日期:2011-08-25 出版日期:2011-10-20 发布日期:2011-10-20
  • 通讯作者: 翟秀静

Penetration of Electrolyte Containing KF and LiF into Graphite Cathode during Aluminum Electrolysis

ZHANG Yue-hong ZHAI Xiu-jing WANG Yao-wu PENG Jian-ping LI Bin-chuan FENG Nai-xiang   

  1. School of Materials and Metallurgy, Northeastern University School of Materials & Metallurgy, Northeastern University School of Materials and Metallurgy, Northeastern University School of Materials and Metallurgy, Northeastern University School of Materials and Metallurgy, Northeastern University School of Materials and Metallurgy, Northeastern University
  • Received:2011-07-21 Revised:2011-08-25 Online:2011-10-20 Published:2011-10-20
  • Contact: ZHAI Xiu-jing

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被引次数

19

摘要： 研究了Na3AlF6-Al2O3-KF-LiF电解质体系中KF和LiF含量、电流密度和NaF/AlF3分子摩尔比对阴极石墨材料渗透过程的影响. 结果表明，K和Na渗透到阴极碳块中形成石墨层间化合物，而Li在阴极表面生成Li2C2化合物；当钾盐含量为0~7%(w)时，碱金属渗透深度可达28~40 mm；当锂盐含量为0~7%(w)时，渗透深度为28~15 mm. 此外，电解质的渗透程度还与电解工艺参数有关，随电流密度和分子比增加而增大；当锂盐含量在3%(w)以内时，选择合适的电流密度和分子比均可减小K, Na, Li对阴极的破坏；3种金属对阴极的破坏作用随钾盐含量增加而增大.

关键词: 铝电解, KF, LiF, 电解渗透, 电流密度, 分子比

Abstract: The effects of KF and LiF contents in the melt electrolyte, current density and molecular ratio of NaF to AlF3 on the penetration into graphite cathode were investigated during aluminum electrolysis using NaF-AlF3-Al2O3-KF-LiF system in laboratory scale. Alkali metals including K, Na and Li penetrated into graphite cathode were detected. It was found that K and Na were converted into graphite intercalation compounds (GICs) as penetrating into cathode, and that Li reacted with C Li2C2 formed on the surface of cathode. The penetration deepness of the alkali metals increased with increasing of content of KF in the melt. And deeper penetration in graphite cathode was observed as increasing of current density and molecular ratio of NaF to AlF3. When the KF content was not more than 3%(w), electrolysis operation with the appropriate current density and molecular ratio could reduce the cathode destructivity caused by the alkali metals penetration.

Key words: aluminum electrolysis, potassium fluoride, lithium fluoride, cathode penetration, current density, molecular ratio

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