Abstract
Solvent extraction experiments were performed to separate platinum and rhodium from mixed chloride solution by using amine and neutral extractants. Effects of extraction conditions on the separation of the two metals were investigated as a function of extractant concentration in the HCl concentration range from 1 to 9 mol/dm3. Alamine304-1, Alamine308, Alamine336, Aliquat336, TBP, TOPO and DOS were tested in our study. The concentration of Pt(IV) and Rh(III) in the mixed solution was fixed at 0.001 mol/dm3 and 0.0001 mol/dm3, respectively. In the extraction with amine, Pt was completely extracted irrespective of HCl concentration, while the extraction percentage of Rh depended on extraction condition. In the extraction with neutral extractants, the extraction percentage of Rh was nearly zero whereas 1 mol/dm3 TOPO completely extracted most of Pt in our experimental range. Separation of Pt from Rh by amines except Alamine336 was possible only from 9 mol/dm3 HCl solution, while complete separation of the two metals by TOPO was possible in the HCl concentration range from 1 to 9 mol/dm3. From the consideration of the economics of the separation process, our results indicate that TBP is better than TOPO in separating Pt and Rh from chloride solution.
