| Bioleaching is one of the methods for the exploitation of low grade sulphide copper. It is economical and efficient, which requires moderate capital and low cost. Moreover, bioleaching is environmentally and it has become hotter and hotter in the area of metallurgy.First, the paper aiming at two bioleaching bacteria separating from Bameng Huo copper mine. Focuses on morphological characteristics and physiological characteristics of the two bacteria,one is Acidithiobacillus ferrooxidans(A.f), the other is Acidithiobacillus thiooxidans(A.t). And, Both are gram-negative bacteria. The mean size of A.f is 0.5×1.5μm,the optimum temperature is 30℃, and the optimum pH of A.f is 2.5. The mean size of A.t is 0.4×1.0μm,the optimum temperature is 30℃, and the optimum pH is 2.0. Before leaching experiment, bacterial strain has carried out docile culture on the two kinds. After three generations in the domestication of bacteria were studied two kinds of strains oxidative activity and found that adaptability and oxidative activity were significantly increased. 150mmol·L-1 Fe2+ is completely oxidized by A.f in 10 days down to 7days. Growth lag phase of A.t has shortened, and its pH turn from 2.0 to 1.48.Minerals used in the experiment took from Bameng Huo scrap copper mine. After multi-element analysis, the copper content was only 0.54%, belongs to low-grade sulfide copper. As high content of consuming sour matter, before leaching experiment has made acidified processing to the mineral. Acid test has shown that as the granularity reduction, acidification of the times and consumption of acid has increased. 20-40mu and 60-80mu need four times'acidification,120-140mu need six times and 180-200mu needs eight times.It is the main body of the paper to use the mixed bacteria of A.f and A.t to leach out the low-grade sulfide copper mine.The results show that the largest leaching rate is up to 75.6% in the mix-leaching experiment, compared with the biggest leaching rate 58.8% using iron-oxidizing bacteria alone, which has put up 16.8%. And it is 42.2% higher than the leaching rate of the experiment which is using no bacteria. The best craft of mix leaching is:PH1.8, receiving bacteria measuring 10% (of which iron-oxidizing bacteria and sulfur-oxidizing bacteria ratio of 1:2), pulp density 10%,mineral-like particle size 180-200 mesh,30℃,Shake bottle speed 170r/min conditions, leaching 9 days, can reach the biggest leaching rate.In order to take maximum use of low-grade sulfide copper resources to enhance the copper leaching rate, this experiment attempt to strengthen bacteria mix-leaching sulfide copper, has tried to find out how FeSO4, Fe2(SO4)3, AgNO3, the activate carbon, Tween-20, Tween-80 materials influence the leaching rate. The results showed that Tween-80 does not play an active role, but will decrease the leaching rate, Tween-20 can accelerate the leaching, but ultimately failed to increase the leaching rate. Adding activated carbon and AgNO3 made leaching rate increased about 5%. Putting FeSO4, Fe2(SO4)3 can make leaching rate rise to 90%, there are strict requirements, the excess volume will suppress bacteria's oxidized activity and reduce leaching rate.
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