METHOD OF PROCESSING WASTES OF SEMICONDUCTOR GALLIUM COMPOUNDS Russian patent published in 2003 - IPC

FIELD: production of rare-earth metals; processing wastes of semiconductor compounds on base of gallium. SUBSTANCE: proposed method consists in mixing gallium wastes with sodium hydroxide, solid oxidizer and retarder-loosener, heating to temperature of 340-450 C, leaching the sinter thus obtained with water and settling P, As and Sb elements by adding alkali or circulating electrolyte to leached solution. Used as solid oxidizer are Na₂O₂, NaNO₃ or NaNO₂; used as retarder-loosener is sodium carbonate or phosphate-gallate, arsenate-gallate, antimonate-gallate or phosphate-arsenate-anitomonate sinter obtained beforehand. Components are taken in the following mass ratio: sodium hydroxide : oxidizer:retarder-loosener equal to (1-1.5) : (0.75-1.5) : (0.5-2). Deposition of P, As and Sb elements is performed in form of phosphate, arsenate or sodium antimonate at concentration of NaOH in solution of 130 to 190 g/l. EFFECT: increased extraction of gallium; universality of process. 4 cl, 1 tbl, 1 ex