供电负荷不稳导致铝电解槽炉底压降升高的预防及控制

Prevention and control measures of the cathode voltage drop rise of aluminum electrolytic cell due to unstable power supply load

针对某电解铝企业供电负荷不稳导致电解槽炉底压降快速升高的问题,进行了分析和处理,最终炉底压降显著降低并得到了长期稳定的控制。结果表明:计划性的短期降负荷,采取预防措施,能有效控制炉底压降的升高;长期供电负荷不稳导致炉底压降升高的因素中,沉淀、结块增多、伸腿长大使阴极导电面积缩小是主要原因,但钠渗透膨胀也必然伴随其中;通过合理调整参数、人工清理槽底沉淀和结壳,炉底压降能显著降低,但不易恢复到初始值;稳定控制分子比、槽温、铝水平等参数,且使阴极表面温度略高于电解质初晶温度,是保持炉底压降长期稳定的关键。

In this paper,the problem of rapid rise of cathode voltage drop(CVD)in an aluminum smelter was analyzed and addressed.Finally,the CVD was reduced significantly and maintained stably for a long time.The results showed that the preventive measures could effectively control the rise of the CVD for the planned short-term load reduction.Among the factors that lead to the increase of the CVD caused by the long-term unstable power supply load,the reduction of the conductive area of the cathode due to the increase of sludge,crusts and the growth of side ledge was the main reason,and the sodium penetration and expansion were also inevitable.The CVD could be significantly reduced by adjusting the parameters reasonably and clearing the sludge and crusts on the cathodes surface manually,but it was not easy to recover to the initial value.It was key to keeping the CVD stable over the long term by controlling parameters stably,such as molecular ratio,bath temperature and aluminum level,and ensuring that the cathode surface temperature was slightly higher than the liquidus temperature of the bath.