Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans
Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans作者机构:School of Minerals Processing and Bio-engineering
出 版 物:《中国有色金属学会会刊:英文版》 (Transactions of Nonferrous Metals Society of China)
年 卷 期:2004年第14卷第2期
页 面:383-387页
核心收录:
学科分类:081902[工学-矿物加工工程] 0819[工学-矿业工程] 08[工学]
基 金:Project(2 0 0 2 0 5 3 3012)supportedbytheDoctoralFoundationofEducationalAdministration,China project(5 992 5 412)supportedbyNationalNaturalScienceFoundationforDistinguishedYoungScholarofChina
摘 要:The mechanism of attachment and leaching of thiobacillus ferrooxidans(T.f.) on chalcopyrite were studied. The shaking flasks with bacteria were observed by SEM. The process of T.f attached to the surface of the mineral sample and the biofilm forming were described. The promoting role of the biofilm for bioleaching was discussed. The existence of Fe2+ in the exopolysaccharide layer of T.f was demonstrated by EM(electronic microscope)cell-chemistry analysis. These results show that under the proper growth condition of bacteria, bioleaching of chalcopyrite results in the formation of complete biofilm after 23 weeks. There are iron ions in the outer layer polymer of T.f., which provides the micro-environment for themselves, and can guaruntee the energy needed for the bacteria growth in the biofilm. At the same time, Fe3+ions produced oxidize sulfide which brings about the increase of both growth rate of the bacterial and leaching rate of sulfide minerals.