Study On Enhanced Bioleaching On Heavy Metal Of Copper Tailings By Electromagnetic Field

This article in view of pollution problem of heavy metal in tailing, the heavy metalin copper tailing were leached by bioleaching which had a lot of characteristics such asgentle reaction, low energy consumption, environmental friendly, process short etc. Inthe leaching process, the leaching rate of heavy metal was very low, in order to improvethe leaching rate of heavy metal, a method strengthened bioleaching was researchedwith Electromagnetic Field, with the purpose of reduce the pollution to the environmentand the harm to human from heavy metal in tailing.First, particle size analysis and composition analysis were researched for thecopper tailing samples which was from Yunnan.The result of particle size analysisshowed that the average particle size of tailing is85.34μm, the grain size was suitablefor bioleaching. The result of composition analysis showed that there are a lot of iron,sulfur and other elements, providing rich nutrients for bacteria in leaching process.There are plenty of heavy metal in copper tailing, such as Cu, Mn, Zn, As, Pb and Cd.Then, the influence of water treated by different Electromagnetic Field onbioleaching were researched. The results showed that under the conditions of inoculum10%, pH2.0, pulp density5%, leaching temperature30℃, different magneticinductionintensity, the leaching rate of Cu, Cd, Zn and As separately were increased from26.64%,6.98%,25.28%and21.37%to29.27%,9.76%,29.27%and26.59%in leaching systemby At.f, the leaching rate of Cu, Cd, Zn and As separately were increased from17.87%,6.15%,21.02%and3.06%to30.37%,7.62%,21.7%and10.15%in leaching system byAt.t, the leaching rate of Cu, Cd, Zn and As separately were increased from22.8%,6.85%,24.46%and13.58%to31.68%,9.48%,31.34%and24.73%in leaching systemby At.f and At.t.Again, under the conditions of magnetic induction intensity separately were1mT、2mT、5mT、8mT and11mT, bioleaching of copper tailing was researched withself-made bioreactor using alone At.f and together At.f with At.t in this paper. Theresults showed that under the conditions of inoculum10%, pH2.0, pulp density5%,leaching temperature30℃, different magnetic induction intensity, the leaching rate ofCu, Cd, Zn and As separately were increased from15.6%,6.64%,29.15%and4.32%to24.06%,8.99%,44.79%and10.74%in leaching system by At.f, the best magneticinduction intensity in bioleaching of Cu and As were11mT, and the best magnetic induction intensity in bioleaching of Cd and Zn were2mT. the leaching rate of Cu, Cd,Zn and As separately were increased from26.47%,7.4%,22.33%and4.85%to36.55%,8.36%,54.08%and8.17%in leaching system by At.f and At.t, the best magneticinduction intensity in bioleaching of Cu, Cd and As were5mT, while the best magneticinduction intensity in bioleaching of Zn was2mT.Finally, the influence of mechanism of bioleaching by Electromagnetic Field werediscussed mainly from two aspects. First, the physical properties of water was changedby Electromagnetic Field, for example, water oxygen and pH of water was increased.Second, the growth of At.f was accelerated, the growth cycle of bacterial was shortenedand oxidative activity of bacterial was improved.