铝电解槽换极过程界面变形和阳极电流分布变化规律研究

Study on the evolution rule of interface deformation and anode current distribution in aluminum pots during anode changing

换极操作是预焙铝电解槽生产中非常重要的一项操作。新极最开始不能导电这一特点,使得电解槽的稳定性在换极过程中受到了很大的冲击。本文建立了电磁场与流场的计算机仿真模型,利用该模型模拟了换极前后铝液中水平电流和铝液界面变形情况,结果显示,相比换极前,换极后的最大水平电流能够达到不换极时的2倍~3倍,铝液电解质界面变形幅度增加4~10 mm,界面变形超过10 mm和20 mm的面积占比增加了1.5倍和2.3倍。在电解槽上安装了阳极电流监测系统,以大量的阳极电流测量数据为依据,对换极前后的阳极电流大小、波动程度和电流恢复速度的变化情况进行了比较分析,结合仿真模型的结果解释了阳极电流大小和波动发生变化的原因,并提出了加快电流恢复的建议。

Anode changing is a very important operation in prebaked aluminum pots. Considering that the new anode cannot conduct electricity at the very beginning, the stability of aluminum pots is greatly impacted during the anode changing process. In this paper, the computer simulation model for electrical field and flow field is built, which is used to simulate horizontal current in the metal and interface deformation before and after the anode changing. The results show that compared to conditions before anode changing, the maximum horizontal current after the anode changing is 2 times~3 times higher than that without anode changing, the bath-metal interface deformation increases by 4~10 mm, and the area ratio of interface deformation exceeding 10 mm and 20 mm increases by 1.5 times and 2.3 times, respectively. The anode current monitoring system is installed on aluminum pots. Based on the large amount of anode current measurement data, the current, volatility and current recovery rate before and after the anode changing are compared for analysis. Combined with results of the simulation model, the reasons for the anode current and volatility are clarified, with suggestions proposed to speed up the current recovery.