RECOVERY AND SEPARATION OF PLATINUM-GROUP METALS USING IMPREGNATED RESINS CONTAINING ALAMINE-336

The kinetics and equilibrium extraction of Pd(II), Pt(IV) and Rh(III) from hydrochloric acid media using impregnated resins containing Alami ne 336 impregnated onto Amberlite XAD2 were studied and compared. Whil e Rh(III) was hardly extracted, Pd(II) and Pt(IV) extraction could be explained by the formation of (R3MH+)(2)MCln-2 complexes: n=4 for Pd(I I) and n=6 for Pt(IV). Stripping and concentration of the extracted PG Ms were assayed with HCl, HClO4 and thiourea. Straightforward metal se parations were designed on the basis of the results obtained in the si ngle metal experiments, and selective co-extraction of Pd(II) and Pt(I V) from Rh(III) at low HCl concentrations, as well as partial separati on between Pd(II) and Pt(IV) at high acid concentrations, were achieve d.