Bioleaching of chalcopyrite with Acidianus manzaensis YN25 under contact and non-contact conditions

Abstract In order to investigate the contributions of contact and non-contact cells of Acidianus manzaensis ( A. manzaensis ) YN25 to the bioleaching of chalcopyrite, three experiments were carried out in the modified shake flasks. The redox potential, pH, cell density, copper and iron ions in the solution were monitored, and the morphological feature and chemical composition of the leached residues were analyzed. The highest leaching efficiency of Cu and Fe was reached in the experiment where the A. manzaensis YN25 could contact the surface of the chalcopyrite. There was no precipitation of jarosite in the leached residues of three experiments, but there was elemental sulfur in the leached residues when the cells could not contact the chalcopyrite. From these results, it is apparent that the leaching of the chalcopyrite is the cooperative action of the contact and non-contact A. manzaensis YN25.