Investigation of the leaching of chalcopyritic ore in acidic solutions

This work presents an investigation of the leaching of chalcopyrite ore using sulphuric acid. The influence of solid/liquid ratio, sulphuric acid concentration and iron(III) concentration on leaching process were examined. Investigations were carried out in PVC columns by percolation of leaching solution through the ore layer which consisted of 8 kg of 0–5mm ore. It was established that the highest dissolution of minerals is at solid/liquid ratio of 4:1. An increase in the solution pH results in an insignificant increase in the chalcopyrite oxidation rate. Iron(III) concentration has no important influence on copper leaching rate. Open circuit potential was measured in leaching solutions. Chronoamperometric measurements are showed that the chalcopyrite surface is passivated at lower potentials; this was confirmed by the small current densities observed using electrochemistry.