Method for Continuous Purification of Metals by Fractional Crystallization in Rotary Drums

摘要

A continuous purification of metals, especially aluminium, is based on the fractional crystallisation on the cooled surface of a rotating cylinder dipping in a trough with molten metal. The distance between the bottom of the cylinder and the bottom of the trough is controlled to a value below the max. thickness of the crystal layer so that the crystals are compressed. This creates an upstream and an independent downstream zone. To re-melt the crystals in the latter zone, the cylinder surface between two radial boundaries of a sector is heated and at least a part of the melt due to the re-melting is extracted.