RECOVERY OF GALLIUM FROM ALKALI METAL ALUMINATE BY LIQUID ALLOY TREATMENT AND ELECTROLYSIS

摘要

A process for recovering gallium from alkali metal aluminate solutions which comprises treating the starting alkali metal aluminate solution with a reagent capable of binding hydroxyl ions so as to reach a concentration of caustic alkali of from 0.1 to 10 g/l, whereafter the liquor obtained is evaporated to a concentration of the caustic alkali therein of from 30 to 150 g/l. Then the evaporated solution is corrected to obtain a ratio of alkali metal oxide to alumina of above 2.0. The corrected solution is treated with a liquid alloy of gallium containing an element having an oxidizing potential exceeding that of gallium to give a concentrate containing more than 90% of gallium by weight, whereafter gallium of a higher purity grade is electrochemically recovered from the resulting concentrate. The process according to the present invention makes it possible to recover gallium from alkali solutions resulting from the treatment of nephelines with the production of a 90% gallium concentrate, from which gallium of an increased purity is obtained at relatively low cost. Processing of the concentrate with the production of gallium is simple, it is not accompanied by any additional expenses and requires no additional equipment. Another advantage of the process resides in a more comprehensive utilization of low-grade aluminium-containing ores.