RECOVERY OF PRODUCTS FROM NON-METALLIC PRODUCTS DERIVED FROM ALUMINUM DROSS

摘要

A process for recovering one of alumina hydrate, magnesium hydroxide and magnesium aluminate spinel (MgAl2O4) from aluminum dross wherein the dross is processed to a non-metallic product (NMP). The dross may contain fluxing salts which are removed in providing the NMP. The NMP may be derived from aluminum dross which does not contain fluxing salts sometimes referred to as white dross. The process comprises digesting the non-metallic product with an acid selected from the group consisting of sulfuric, hydrochloric, hydrofluoric and phosphoric acid or mixtures thereof to provide a slurry containing dissolved alumina, magnesia and a solid component, for example, containing magnesium aluminate spinel. Instead of an acid, a base such as sodium hydroxide may be used. The slurry is filtered to separate the solid component from the liquid containing dissolved constituents such as alumina and magnesia to recover the solid component.