PURPOSE: To extract Sb and Bi from an aqueous solution acidified with sulfuric acid, in high extraction yield and selectivity, by contacting the solution containing Sb and Bi with a solution of a specific tricarboxylic acid ester in a water- insoluble solvent.
CONSTITUTION: A tricarboxylic acid ester of formula (R1, R2 and R3 are 4W18C alkyl) (e.g. phosphonobutane-1,2,4-tricarboxylic acid butyl ester) is dissolved in a water-insoluble solvent (e.g. kerosine). The obtained solution is used as an extractant, and is made to contact with an aqueous solution containing Sb and Bi and acidified with sulfuric acid to effect the selective extraction of the Sb and Bi from the solution. The Sb and Bi extracted to the water-insoluble solvent solution can be recovered by the back extraction of the solution with hydrochloric acid. The process of the present invention can be suitably applied for the separation of Sb and Bi existing as impurities in the electrolyte in the electrolytic refining of copper.
YASUDA MASAHIRO
WACHI TOSHIO
NOJIMA SHIZUO
OONO ZENICHIROU
ISHIWATARI MASAHARU
MITSUBISHI METAL CORP