Leaching Copper From Liang-Zou Mining Group Old Tailings With Microbiological Method

Bio-metallurgy technology has many advantages such as little pollution, short process, low investment, low cost, mild conditions and easy to separate valuable metals etc. Bio-metallurgy technology has become a mining research hot. In this study, we exploits bio-metallurgy technology leaching copper from Liang-Zou mining group old tailings.The old tailings were produced when Liang-Zou mining group separated chalcopyrite with a flotation process, the reserves of the old tailings reached 700 thousand ton. The old tailings is the secondary sulphide ore, ore structure is very complex. the main components of mineral are chalcopyrite and molybdenite, the copper grade is 0.29%, there is tremendous value in use. In early times, Liang-Zou mining group using flotation process recovered copper, the recovery was only about 50%, and later, It taked acid leaching process, the leaching rate was about 70%.In this study, we took Mining wate underground 200m from Liang-Zou mining group, and cultured in the different mediums, after screening, separation and purification, we got Thiobacillus ferrooxidans (T.f), and studied it's biological indices such as it's optimum tempreture, optimum pH, sulfur oxidative activity etc. preliminary explored the effect of the UV mutagenesis on the T.f. we choosed flask leaching and column leaching, We focused on studing the effects of leaching's pH, inoculum concentration, Ag+, Tween20 on the sulphide mineral leaching.The results show that Tf's optimum growth temperature is 30℃, optimum pH is 2.0, and has sulfur oxidative activity, Fe2+and S0 can be used as it's growth energy. The leaching effect is better when pulp concentration is 10%and inoculum concentration is 10%. Under the condition of no T.f,25d leaching rate can reach 70% of flask leaching, and 25d leaching rate can reach 62% of column leaching, when the inoculum concentration is 10%,25d leaching rate can reach 75% of shaking leaching, In the process of flask leaching, 3 mg/L of Ag+is used as catalyst,25d leachin rate can reach 82%,3 g/L of activated carbon and 3 mg/L of Ag+are used as catalyst combination,25d leaching can reach 94%,3 mL Tween20 and 3 mg/L of Ag+are used as catalyst combination,25d can reach 90%,3% (volume ratio)Tween20 and 3 mg/L of Ag+are used as catalyst combination, it can reach 90%. In the process of column leaching,25d leaching rate can reach 70%,3 mg/L of Ag+ is used as catalyst,25d leaching rate can reach 78%,3 g/L of activated carbon and 3 mg/L of Ag+as catalyst combination,25d leaching can reach 89%,3%(volume ratio) Tween20 and 3 mg/L of Ag+are used as catalyst combination,25d can reach 85%.