Gold, palladium and platinum recovery, as by-products, from the Skouries porphyry Cu-Au deposit, Chalkidiki area, northeastern Greece — preliminary results

Abstract

The Skouries Porphyry Cu-Au deposit (Chalkidiki, Northeastern Greece) exhibits elevated Pd-Pt contents, in both copper ore and in flotation concentrates. The study of the precious metals recovery, is considered to strengthen its economic attractiveness and so its ability for future sustainable development. As a result of this economic potential, a recovery method for the precious metals gold, palladium and platinum was applied on two flotation concentrates derived from large (∼15 K) composite drill-hole samples, composed mainly by chalcopyrite, bornite and pyrite, from the porphyry intrusion at Skouries. The “Final” concentrate (21% Cu, 22g/t Au, 2.4g/t Pd & 0.04g/t Pt) was roasted at 900°C for 2 hours and then leached in 500 ml HCl 6M plus H2O2 0.03M, for 24 hours at 70 °C. The leaching process resulted in the recovery of 96.6% Au, 97.7% Pd and 100% Pt. Although more research is required, these results are considered to be encouraging and, this leaching method can be environmentally friendly under certain conditions.