Morphology of chalcopyrite leaching in acidic ferric sulfate media

Two-dimensional computer simulations based on percolation theory were used to explain the morphology associated with atmospheric chalcopyrite leaching in acidic ferric sulfate solution. The aim of this study was to understand the differences in observed morphology between chalcopyrite residues leached with and without pyrite in the leach environment. The study of chalcopyrite morphology is of interest because there are no records of similar investigations available. Simulations showed high copper extractions from chalcopyrite when surface atoms were mobile leading to agglomeration of like atoms and the formation of highly porous mineral structures. High degrees of surface mobility are associated with active anodic behavior. The simulated morphology was consistent with previously observed residue morphology from chalcopyrite leach experiments in the presence of pyrite. Thus it was found that the enhanced recoveries and peculiar morphology observed during pyrite catalyzed leaching are attributable to active anodic behavior. Conversely, the simulations also showed that the recovery of copper was low when surface atoms were effectively locked in place resulting in mineral passivation. The simulation morphology obtained in this case was also consistent with experimental results of chalcopyrite leached without the presence of pyrite which have shown non-porous film like product layers.