Physical Model of Aluminium Refining Process in the Batch and Continuous Reactors

Abstract

Both primary and secondary aluminium need to be refined. The most popular methods of aluminium refining is barbotage. This method is based on the introduction of refining gas bubbles into liquid metal. It can be done in batch or continuous reactors. The refining gas can be introduced to the metal by lances, ceramic porous plugs or rotary impellers. The gas bubbles generated in this way are then mixed with the liquid metal and the level of mixing depends on the processing parameters such as the flow rate of refining gas or the impeller speed. Five patterns of the refining gas dispersion in the liquid metal are known: no dispersion, minimal dispersion, intimate dispersion, uniform dispersion and over-dispersion. Physical modelling is the best way to visualize these kinds of dispersion. It also helps to choose the adequate processing parameters. However, it is also important to keep the dynamic and geometrical similarities to the refining process. In the paper the physical modelling of the aluminium refining process is presented. Two reactors: URO-200 batch reactor with a rotary impeller and URC-7000 continuous reactor with ceramic porous plugs were taken into consideration.