电极材料对铝电解阴极过程研究的影响

Effects of electrode materials on studying cathode process in aluminium electrolysis

电解铝工业中铝的析出发生在阴极上,研究铝析出反应的机理对实际工况有很好的指导意义。研究发现,炭电极上的Al、Na共沉积现象严重,致使循环伏安曲线上Al的析出峰被掩盖。因此人们试图用一些金属电极Ni、Pt、Au、Ta、Cu、W等来代替炭电极,但研究发现大部分金属电极都与Al反应生成合金,干扰了对真实电极过程的研究。只有W与Al的合金化作用较小,因此对冰晶石-氧化铝熔体的阴极电化学研究采用了W电极。而目前TiB2基可湿润阴极是极具发展前景的铝电解槽阴极材料,但这方面的研究还很不够,需做进一步的研究。

In the Hall-Heroult process, the deposition of aluminium takes place on the cathode, so it is very significant to study the theory of cathode process. Some people have worked and found that Na and Al co-deposition was very serious, which caused the peak of aluminium deposition disappeared on the cycle voltammogram. After that, others tried to replace the graphite cathode with some metal materials, eg Ni?Pt?Au?Ta?Cu?W, but there were no good results becausealmost metals and aluminium could react and produce different alloys respectively. Only the interact of W and Al was little, thus people used the W electrode to study the cathode process in molten cryolite. Now, TiB_2-based wetting cathode is of great prospect, but the study is not enough, so we have a lot of work to do.