Continuous salt-based melting process

Abstract

A continuous salt-based process is provided for melting and reclaiming aluminum from aluminum scrap containing impurities including heating a molten salt in a heat bay, mixing the heated salt with aluminum scrap or skim in a charge bay to form a molten charge mixture, separating aluminum from impurities in the charge bay by coalescing aluminum to form a molten aluminum metal pad, chlorinating a portion of the charge mixture from the charge bay to form a chlorinated salt mixture and metal chlorides, removing metal chlorides from the salt mixture, and feeding the salt mixture back to the heat bay. In one aspect, the chlorinating step of the present invention includes introducing carbon monoxide or, preferably, solid carbon to control oxide concentration. The process further comprises adding fluorides and removing metal chlorides from the salt to maintain a preferred salt composition. The metal chlorides can be removed by withdrawing volatile metal chloride gases and electrolytically reducing metal chlorides in the molten salt.