Bioleaching Of Low Grade Chalcopyrite By Several Major Strains At Different Temperature

In China the most of the copper miner was low grade chalcopyrite. Bioleaching is an economical method for the recovery of metals from minerals, especially from low grade ores, overburden and waste from current mining operations, which requires moderate capital investment with low operating cost. Furthermore, bioleaching is generally more environmentally friendly than conventional metal recovery processes such as concentration and smelting. Some research has shown that temperature is one of the important factors during bioleaching.. In this paper, RT-PCR was used to analysis the changes of microbial communities of mixed bioleaching strains on chalcopyrite. And the changes of bacterial concentration and Cu+leaching rate at different temperatures were also studied. Lixivium At last, the differences of element content in lixivium were analyzed by ICP-AES.We elected Acidithiobacillus ferrooxidans,Letospirillum ferriphilum L.f, Acidithiobacillus thiooxodans A01,Acidithiobacillus caldus S1, Acidiphillum spp DX1-1,Ferroplasma thermophilum L1, A.brierleyi, Sulfolbacillus thermosulfidooxida St,design specific primers and assessment of specific primers. The result shows real-time PCR assay was reliable to analyze population dynamics of eight strains base on16s RNA genes、gyrb genes and functional genes in bioleaching systems. The paper research bioleaching rate was affected by different temperature. The results showed,the higher the temperature, the higher the bioleaching rate.30℃(32.7%),40℃(40.1%) leaching system leaching rate is relatively low,50℃(71.2%),60℃(96.7%) leaching system significantly increased the leaching rate.The rise of the temperature was less effect the bioleaching rate of chalcopyrite when the temperature below the40℃. Bioleaching rate of78%at50℃was far more than bioleaching rate40.1%at40℃.When the temperature at50℃promote bioleaching of chalcopyrite.50℃was the best temperature. Chalcopyrite lattice was much higher, because of higher Chalcopyrite lattice, so chalcopyrite was hard to bioleachingjt was much easier broken Chalcopyrite lattice when higher of the temperature.50℃was the critical temperature that destroy the lattice Chalcopyrite.Paper also researches the variety rule of bioleaching bacteria at the different temperature, result of the research showed that mostly bacteria was L.ferriphilum YSK、At. thiooxodans A01,Autotrophic bacteria at30℃and40℃, but mostly bacteria was F.thermophilum L1、A.brierley、Sulfolbacillusthermosul fidooxida S.t,Facultative bacteria at50℃and60℃。 The lower the temperature the more complex the Colonies construct. Colonies constructs at the early phase were much complex than Colonies constructs at the late phase. The higher the temperature, the longer time of bioleaching,the more singularity.Paper finally research Colonies constructs effected by organic. Organic promote growth of Facultative bacteria, inhibit the growth of Autotrophic bacteria, effect Colonies constructs. The change of Colonies constructs effect bioleaching rate of chalcopyrite.40℃and50℃of the leaching system was significant,40℃leaching system by adding yeast extract was increased by9.7%,50℃leaching system by adding yeast extract was increased by6.8%.