METHOD OF GALLIUM RECOVERY FROM ALAKLI-ALUMINATE SOLUTIONS OF ALUMINA PRODUCTION (VERSIONS) Russian patent published in 2003 - IPC

FIELD: electrochemical recovery of gallium from alkali-aluminate solutions of alumina production. SUBSTANCE: methods of gallium recovery from alkali-aluminate solution of alumina production include electrolysis on solid electrodes stable in working solutions of alumina production in presence of zinc preliminarily introduced into initial solution and in 1-10-fold excess with respect to gallium with obtaining of cathode sediment of zinc-gallium alloy; concentration of gallium in accumulating solution by dissolving the obtained cathode sediment; subsequent separation of zinc-gallium alloy from solution enriched by secondary electrolysis. Primary electrolysis of working solution is carried by cycles, changing cathodes with anodes, reversing the polarity from cycle to cycle, in combination of moment of polarity reversing with beginning of dissolving of cathode sediment in accumulating solution at temperature of working solution of 20-30 C, with current volume density above 8 but less than 30 kA/cu.m. Dissolving of cathode sediment to concentrate gallium to content not less than 1.5 g/l is carried out with current of reverse polarity under conditions of current stabilization in special accumulating solution in form of separate portion of working solution at temperature of 40-80 C. Gallium alloy is recovered from accumulating solution by secondary electrolysis on solid electrodes (with same values of parameters as in the primary electrolysis) up to level of gallium content in accumulating solution not above its initial content. Obtained gallium alloy is removed by the known method and used accumulating solution is returned to process of alumina production. EFFECT: higher efficiency of methods due to process intensification. 20 cl