Abstract:Taken a 300 kA aluminum electrolysis cell in some aluminum company in Henan province, a novel low temperature electrolytic model with a geometric similarity ratio of 1:4 to its prototype was designed and constructed based on the principles of geometric and dynamic similarities. In addition, the bubble nucleation, growth, coalescence, breakup and detachment underneath the anode were recorded. The results show that electrolytic bubbles are first nucleated uniformly under the entire anode surface with small size. Then these bubbles grow up uncreasingly through the growth process caused by gas diffusion and mass transfer and the coalescence process caused by collision and swallowing. And finally some large bubbles escape from the edge of the anode bottom and break up into more smaller bubbles with a large amount of liquid flow. The bubble layer underneath the anode has a broad bubble size distribution and differs greatly in shape. The whole anode is covered by a few large and medium-sized bubbles and a large number of small bubbles. Changing current density and anode inclination angle has an important influence on some dynamical behavior mechanisms and distribution characteristics of the bubbles above.

Key words: aluminum electrolysis; anodic bubble dynamics; distribution characteristic; low temperature electrolysis; experimental research