EFFECT OF COEXISTING ALUMINUM ON SOLVENT-EXTRACTION OF GALLIUM FROM MIXED AQUEOUS-SOLUTIONS WITH 2-BROMODECANOIC ACID

The effects of coexisting Al ion on the extraction equilibrium and the extraction rate! of Ga with 2-bromodecanoic acid (2BDA) have been stu died. It was found that bath distribution ratio and extraction rate of Ga increase when Al ion coexists. The results of the equilibrium expe riment showed that Ga was coextracted with Al. The extraction equilibr ium and equilibrium constant of Ga-Al mixed-metal carboxylate complex were determined, and experimental results could be explained by the fo rmation of the complex. On the other hand, from the results of the ini tial Ga extraction rate experiment, there is no evidence of Ga-AI coex traction. Thus, the acceleration mechanism taking account of the equil ibrium of hydroxide complex species in the aqueous phase is proposed a nd the tendency of experimental results can be explained by the model.