A conceptual hybrid process flowsheet for platinum group metals (PGMs) recovery from a chromite-rich Cu-Ni PGM bearing ore in oxidized mineralization through a single-stage leach and adsorption onto ion exchange resin

Without any prior scrubbing step to remove co-extracted impurities, the uptake of Pd(II) and Pt(IV) was successfully accomplished with recoveries approximating 100% within 15 min. The presence of Fe(III) and other non-ferrous metal accompanying ions didn't show any marked tendency to adsorb. Among the adsorption parameters, thiocyanate concentration had the most significant effect on the process. The dual role of Sn(II) i.e. labilizing agent and PGM collector at a time, was simply overridden, overshadowed by the DEAE high selectivity for PGMs. Thiourea proved to be a better stripping reagent for bulk elution of combined Pd(II) and Pt(IV). A conceptual flowsheet is disclosed for hydrometallurgical pilot scale testing, economic evaluation and assessment of potential environmental impacts.