CONTINUOUS EXTRACTING APPARATUS AND METHOD FOR EXTRACTING METAL USING IT

PROBLEM TO BE SOLVED : To provide a recovering method for further enhancing an extraction efficiency and a recovery rate of a noble metal or an expensive rare metal, by solving a problem that a distribution coefficient often decreases in the process widely adopted for extracting the salt of the metals with an organic solvent and concentrating it in order to recover the metals. SOLUTION : This apparatus is a continuous countercurrent extraction apparatus, and comprises separation chambers for a raw solution to be extracted and an extracting solvent arranged in upper and lower parts, an extraction chamber arranged in the intermediate part between them, and one or more chemical-solution injection openings and stirrers for adjusting the distribution coefficient, and/or a temperature control device arranged in the extraction chamber. A usable organic phosphate compound-based solvent includes, for instance, tributyl phosphate or di(2-ethylhexyl) phosphate. The extraction apparatus extracts and recovers the ions of the noble metal such as platinum or the expensive rare metal such as indium.