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

来源期刊：中南大学学报(英文版)2009年第3期

论文作者：李劼 方钊 赖延清 吕晓军 田忠良

文章页码：422 - 428

Key words：aluminum electrolysis; semigraphitic cathode; low temperature electrolysis; electrolysis expansion; K penetration; Na penetration

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 α_CR (cryolite ratio) and β_KR (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 α_CR. When α_CR=1.9 and β_KR=0.5, the electrolysis expansion is the highest, which is 3.95%; and when α_CR=1.4 and β_KR=0.1, the electrolysis expansion is the lowest, which is 1.28%. But the effect of β_KR is correlative with α_CR. When α_CR=1.6 and 1.9, with the increase of β_KR, the electrolysis expansion and K/Na penetration rate increase. However, when α_CR=1.4, the electrolysis expansion and K/Na penetration rate firstly increase and then decrease with the increase of β_KR.

基金信息：the Major State Basic Research and Development Program of China
the National High-Tech Research and Development Program of China