Atmospheric leaching of copper flotation concentrate with oxygenated sulphuric acid solutions

Results of atmospheric leaching of copper sulphide concentrate from Lubin Concentrator (ZWR Lubin) with oxygenated aqueous H2SO4 and in the presence of Fe(III) have been presented. It was found that oxidative atmospheric leaching performed in acidified and oxygenated iron(III) solutions has to be preceded by a controlled, non-oxidative decomposition of acid-consuming carbonate components in order to further liberate finely disseminated metal-bearing minerals. Atmospheric leaching appeared to be a very efficient process for recovering Cu, Zn, Co and Ni from the Lubin concentrate due to favorable mineralogical composition and fine size of leached particles. A maximum recovery of Cu (95%), Zn (90%), Ni (40%) and Co (50%) was observed after 5-7 hours of leaching at 90C in the oxygenated solutions containing 20-30 g/dm3 of Fe(III). The solid residue after atmospheric leaching will be further processed by flotation or chloride leaching to recover Ag, Pb and precious metals.