Bioleaching of Chalcopyrite by a Mixed Culture of Moderately Thermophilic Microorganisms
A mixed culture of moderately thermophilic microorganisms was enriched from Acid Mine Drainage (AMD) samples collected from several chalcopyrite mines in China, which can leach copper from chalcopyrite effectively. Its tolerance to chalcopyrite was brought up to 80 g/L after being adapted to gradually increased concentrations of chalcopyrite.The effects of several leaching variables on copper recovery in Stirred Tank Reactor had been investigated. The ore contained chalcopyrite (62.2%) and galena (25.6%) as the main sulfide minerals. The results of the tests show that it is possible, operating at 8% of pulp density to attain copper extraction of 75% in 44 days. The leaching rate of chalcopyrite tends to increase with the dissolution of total iron. Microscopic counts of microorganisms in the solution tend to be higher at low pH range. Furthermore, the analyses of leached residues indicate that the passivation of this chalcopyrite is mainly due to the formation of a mass of jarosite and anglesite (about 48.3% and 21.7% in residue respectively), other than elemental sulphur layer.The bacterial community composition was analyzed by using amplified ribosomal DNA restriction analysis (ARDRA). Two moderately thermophilic bacteria species were identified as Leptospirillum ferriphilum and Acidithiobacillus caldus, with different proportion in the bio-pulp, 67% and 33%, respectively.
Moderately thermophilic microorganisms Stirred tank reactor Chalcopyrite Residue analyses Community composition
W. M. Zeng H. B. Zhou G. Z. Qiu
School of Minerals Processing and Bioengineering, Central South University, Changsha, China Key Laboratory of Biometallurgy, Ministry of Education, Changsha, China
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
2634-2643
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）