Bubble behavior in aluminum reduction cell with inert anode

Abstract

The bubble behavior is one of the key factors for the design and the process of aluminum reduction cell using inert anode. A see-through cell is constructed to investigate the bubble flow behavior and the electrolyte flow pattern induced by bubbles. The test results show that the electrolyte is driven by the bubble to move around the cathode, and also some vortices occur in local areas. The bubble generated at the anode bottom undergoes the processes of formation, growth, sliding, detachment and coalescence. However, the bubble generated at the middle of anode detaches rapidly from the anode surface and moves upward and collides with other bubbles, which results in coalescence or break-up. Most bubbles are released into the atmosphere at the liquid surface, while some other bubbles taken by the electrolyte flush to the height higher than the mean horizontal level of the liquid and then drop down and move horizontally and they are released finally. Some bubbles are kept unbroken and are sliding on the electrolyte surface. The diameter of bubble generated at inert anode is smaller than that of bubble generated at graphite anode. Moreover, the bubbles on inert anode are spherical, which was different from those in tubular or disk form on graphite anode.

Keywords

inert anode / bubble / diameter / releasing

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