Study on bioleaching of different types of chalcopyrite

Bioleaching of chalcopyrite with two different types,pyrite type and porphyry type,was compared.It is shown that there is a great difference in leaching efficiency.After 48d,the copper leaching rate reaches 46.96% for the pyritic chalcopyrite,while it is 14.5% for the porphyry chalcopyrite.Based on the analysis of Fe²⁺,Cu 2p spectra on the chalcopyrite surface and deposit characteristics,a moderate amount of Fe²⁺ can promote bioleaching of the two kinds of chalcopyrite,but their optimal dosages are distinct.Different products appear on the surfaces of leached residues,and there is a copper-rich layer on the porphyry chalcopyrite,which hinders a greater copper extraction.Compared with the crude ore,Cu peak shift to lower binding energies was observed,following the leaching mechanism suggested by Hiroyoshi et al.the difference in bio-leaching between them is dependent on the integration of many factors such as metallogenic rock,wall rock,associated minerals and elements,metallogenic temperature and pressure.