Recovery of copper resource from mine solid waste using microbial technology

As the main source of mine solid waste, tailings can lead to a range of social issues, such as taking up a lot of land, destroying the ecological environment, and producing security risk. The more important problem is that tailings contain a large number of valuable resources. In this paper, a copper tailing of Hubei province, with average copper grade of 0.2%, was regarded as the object. Recovery of copper resource from tailings using microbial technology was mainly researched. Leaching bacteria was isolated from acid mine water of this copper ore. The optimal cultivating conditions were obtained as temperature 30°C, the initial pH value 2.0, and inoculation amount 10%. Under these conditions, the oxidation rate of Fe
²⁺
reached 100% after culturing 40 hours. The researches on the different stages of domestication of mixed bacteria were conducted through gradually simulating the tailing environment. The copper leaching rate reached to 41.71% after 28 days and it was only 4.42% in chemical leaching process. Witch shows that the effects of bio-leaching were much better than the effects of chemical leaching and the mixed bacteria had a good ability to leach low grade copper tailings.