Investigation of bioleaching of a low grade nickel-cobalt-copper sulfide ore with high magnesium as olivine and serpentine from Lao

摘要

Shake flask bioleaching of a low-grade nickel-cobalt-copper sulfide ore from Lao was investigated to test the technical feasibility to recovery metals from this ore. The mineralogical results indicated that the valuable minerals were disseminated finely and the ore had a low content of sulfur and high content of iron and magnesium, which was very harmful for bioleaching. The effects of different parameters such as the amount of acid addition, inoculation volume, initial pH, temperature and leaching time on the bioleaching performance of the ore were evaluated after pre-leaching with dilute acid. The results showed that nickel, cobalt, copper leaching rates reached 81.61%, 80.75%, 70.97% at 33°C and 83.40%, 82.13%, 70.34% at 45°C. The mineralogical analysis of the leaching residues revealed that the leaching rate of nickel sulfide was more than 92% and the unleached nickel was mainly present as nickel silicate.