Bacterial leaching of a copper sulphide ore containing activated pyrite

Bioleaching of a copper sulfide ore containing activated pyrite has been studied using a mixed culture of mesophilic bacteria. Microscopic observations showed that pyrite was coated by a thin film of chalcocite mineral and therefore, this kind of copper ore is not suitable for flotation, as a concentrate containing more iron and less copper will be produced. Hence, a bioleaching process was considered as an alternative to treat this ore. Following shake flask and acid consumption tests, column tests of the crushed ore (75% –12.5 mm) were initiated and the effects of culture medium, agglomeration, and irrigation type on copper recovery were studied. Results showed that all the columns containing bacteria had copper recoveries around 90% compared to the abiotic control column with a recovery of 50%. Bioleaching can easily be applied for copper ores containing pyrite rimmed with a thin layer of chalcocyte.

Bacterial leaching of a copper sulphide ore containing activated pyrite Keywords:

Bacterial leaching , activated pyrite , copper sulfide ore