铝电解过程阳极气泡的析出行为

铝电解过程阳极生成的气泡在排放过程中的运动带动电解质的流动，其流动行为影响氧化铝的溶解和金属的二次反应，对电解过程影响较大。采用透明槽进行铝电解实验，用高速照相机和摄像机记录电解过程中的气泡行为并进行分析。结果表明，气泡的生成分为两个阶段：第一个阶段为气泡在阳极底部的生长，第二个阶段为气泡脱离阳极底部在电解质中上升。在阳极电流密度0.7 A/cm2下电解，在气泡生长阶段阳极底部气泡层的最大厚度为0.4 cm，气泡生长到最大需要的时间为12 s，气泡脱离阳极底部在电解质中上升需要的时间为0.27 s。整个电解过程，阳极侧部小气泡不断长大、逸出，采用Matlab数学处理软件，用直方图均衡化方法处理摄像机拍摄的实验图像，可获得阳极侧壁的气泡的生成的清晰图像，用于深入观察和分析气泡的析出行为。

Behavior of Anodic Bubbles precipitation in Aluminum Electrolytic process

The movement of anode bubbles in aluminum electrolysis cell is the main force of electrolyte flow. Its flow behavior affects the dissolution of alumina and the secondary reaction of metals, and has a greater influence on the electrolytic process. In this paper, the bubbles behavior of aluminum electrolytic cell is recorded by high speed camera and camera through the aluminum electrolysis experiment in transparent electrolytic cell. The results show that there are two stages of bubbles behavior. The first stage is the growth stage of the bubbles at the bottom of the anode, the second stage is the stage of the bubbles rising from the bottom of the anode in the electrolyte. The electrolysis is carried out at an anode current density of 0.7 A/cm2. It takes about 12 s for bubbles growth to the maximum thickness of 0.4 cm at stage 1, and it takes 0.27 s for the bubbles escape from anode bottom to electrolyte free surface at stage 2. Small bubbles on the anode sidewall grow up and escape continuously during the whole electrolysis process. The experimental images taken by cameras are processed by the histogram equalization method in Matlab. Clear images of the bubbles generated on the anode side wall can be obtained for in-depth observation and analysis of the bubbles precipitation behavior.