TREATMENT OF ALUMINUM DROSS

摘要

A process for preparing calcium aluminate from aluminum dross comprising crushing (10) the dross and extracting solubles therefrom with water in a digester (14). The brine so obtained is processed in a crystallizer (32) to obtain fluxing (32 (a)) materials contained therein, and the insolubles are fumaced (22) to separate the free aluminum metal therefrom. To prevent undesirable reactions from occurring in the digester (14) which result in the production of hazardous and noxious products, the pH in the digester is controlled in the range of from about 5 to about 8, by withdrawing a magnesium chloride-containing stream (32 (b)) from the crystallizer (32 (c)) and introducing it into the digester (14).