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mesophilic-bacteria
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Bacterial leaching of low-grade ZnS concentrate using indigenous mesophilic and thermophilic strains
, Article Hydrometallurgy ; Volume 85, Issue 1 , 2007 , Pages 59-65 ; 0304386X (ISSN) ; Yaghmaei, S ; Vossoughi, M ; Jafari, A ; Roostaazad, R ; Turunen, I ; Sharif University of Technology
2007
Abstract
In this study low-grade sphalerite has been treated by the bioleaching process using native cultures of Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfido-oxidans in order to determine the ability of these bacteria to the leaching of zinc. The effects of bacterial strain, pH, temperature, pulp density, iron precipitation, and initial concentration of ferric iron on the zinc leaching were evaluated. The bioleaching experiments were carried out in shake flasks at pH 1.5, 180 rpm, 33 °C and 60 °C for mesophilic and thermophilic bacteria, respectively. Compared with the use of laboratory reference strains or control conditions, zinc recovery from the respective concentrate was...
Thermal Simulation of Bioheap
, Ph.D. Dissertation Sharif University of Technology ; Sadrnezhad, Khatiboleslam (Supervisor)
Abstract
Nowadays, because of drastically decrease of copper sulfide ore’s grade, and difficulties in leaching of them, new processes of copper production like bioleaching technique become significant. Finding the optimal conditions for bioleaching, require investing a lot of time and cost. Computer simulation is useful in this case. Temperature, affects the kinetics of dissolution reactions, type and growth rate of bacteria, and finally, rate and amount of recovery of valuable copper metal from ores, so determination of temperature within the bioheap is very important. Thermophiles are better than mesophiles in chalcopyrite bioleaching and in the range of 55 to 65 degree centigrade, thermophiles...
Leaching of a zinc ore and concentrate using the Geocoat™ technology
, Article Minerals Engineering ; Volume 24, Issue 1 , 2011 , Pages 64-69 ; 08926875 (ISSN) ; Petersen, J ; Roostaazad, R ; Hosseini, S ; Mohammad Mousavi, S ; Najafi, A ; Vasiri, A. K ; Sharif University of Technology
Abstract
In this study, the Geocoat™ technology was used for the extraction of zinc from a mineral concentrate obtained from the Kooshk mine (Yazd, Iran) by a culture dominated by the mesophilic bacterium Acidithiobacillus ferrooxidans in a packed column bioreactor. A low grade sphalerite ore was used as support for the concentrate coating. During the 100 days of leaching pH, Fe3+, Fetotal, microbial population density and zinc extraction were measured. The final zinc extraction from concentrate and low grade support was 97% and 78%, respectively, and it was found that leaching from the support does not proceed significantly before leaching from the coating is completed