高电流密度TiB2/G阴极泄流式铝电解槽的电解实验
来源期刊:中国有色金属学报2008年第4期
论文作者:彭建平 冯乃祥 姜艳丽 王耀武 尤晶
文章页码:738 - 738
关键词:铝电解;泄流式电解槽;石墨化阴极;TiB2
Key words:aluminum electrolysis; drained cathode cell; graphitized cathode; TiB2. coating; overvoltage 摘 要:详述了泄流式TiB2/G阴极电解槽的制作与电解运行操作。在焦粒焙烧、干法启动后,保持1.54 A/cm2的高阳极电流密度进行140 h电解实验,平均电流效率为86.5%。实验过程中,TiB2/G层稳定而牢固,其腐蚀脱落速度为0.4 g/(h·m2),能很好地保护阴极基体。利用铝参比电极由瞬时断电技术测得泄流式电解槽的阳极过电压和阴极过电压,它们与对应的电流密度遵循塔菲尔方程关系,其阳极过电压与工业电解槽相当,而其阴极过电压比工业电解槽的高0.4 V左右。这可能是由于泄流式电解槽中不存在铝液波动,阴极表面附近的电解质分子比远高于工业电解槽阴极表面的电解质分子比。 Abstract: The construction and testing of a drained cell with TiB2/G graphitized cathode were described. The coke-bed baking method and a dry start-up technology were adopted. During 140 h of electrolysis the drained cell performed steadily at an anodic current density of 1.54 A/cm2 with a current efficiency of 86.5%. After electrolysis it was found that the TiB2 coating layer shows a low wear rate of 0.4 g/(h·m2). Moreover, the overvoltage at different current densities is measured with an aluminum reference electrode by an interruption technique in the drained cell. The results can be depicted as a fairly straight line in a Tafel plot. The anodic overvoltage in the drained cell is close to the value in industrial cells, while the cathodic overvoltage in the drained cell is about 0.4 V higher than that in industrial cells at around 1 A/cm2, due to a stable molten Al layer and high molar NaF/AlF3 ratio of the bath close to the cathode. 基金信息:国家自然科学基金资助项目
高等学校博士学科点专项科研基金资助项目