METHOD FOR SELECTIVE SEPARATION OF CADMIUM FROM AN ACIDIC AQUEOUS SOLUTION

摘要

A method for the selective separation of cadmium from an acidic aqueous solution also comprising co-extractable metal ions is provided. The method comprises contacting an organothiophosphorus solvent extractant with the aqueous solution, the amount of solvent extractant being effective to reduce substantially the concentration of cadmium ions in the aqueous solution without significantly reducing the concentration of other heavy metal ions. Preferably the mole ratio of organothiophosphorus extractant to extractable metal ions is insufficient to extract substantially all of the extractable metal ions, and the organic phase is maintained in contact with the aqueous solution until at least a portion of the co-extractable metal ions are displaced by cadmium, thereby rendering the ratio of Cd:co-extractable metal ions in the organic phase greater than that in the aqueous solution.