Recovery of gallium from coal fly ash by a dual reactive extraction process

The extraction of gallium from coal fly ash by leaching and extraction with commercial extractants Amberlite LA-2 and LIX 54N dissolved in kerosene was studied. Leaching of gallium and other metals from the fly ash was carried out with 6 M hydrochloric acid. The leaching liquor is first contacted with Amberlite LA-2 which extracts the gallium and iron. The iron is then precipitated with sodium hydroxide, while gallium remains in solution. Gallium is extracted selectively from the base solution with LIX 54; the resulting stripped solution contains 83% of the gallium present in the leaching liquor. A flow diagram for this dual-extraction process is proposed. (C) 1997 ISWA.