Interaction mechanism of Cu^(2+),Fe^(3+) ions and extracellular polymeric substances during bioleaching chalcopyrite by Acidithiobacillus ferrooxidans ATCC2370  

嗜酸氧化亚铁硫杆菌(ATCC 23270)浸出黄铜矿过程中的EPS、Cu^(2+)和Fe^(3+)的相互作用机制(英文)

作　　者：余润兰[1] 刘晶[1] 陈安[1] 钟代立[1] 李乾[1] 覃文庆[1] 邱冠周[1] 顾帼华[1] 

机构地区：[1]中南大学资源加工与生物工程学院,生物冶金教育部重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第1期231-236,共6页中国有色金属学报（英文版）

基　　金：Project(50621063) supported by the National Natural Science Foundation of China;Project(2010CB630903) supported by the National Basic Research Program of China

摘　　要：The extracellular polymeric substances（EPS） of Acidithiobacillus ferrooxidans ATCC 23270,and iron and copper enclosed in EPS were extracted by ultrasonication and centrifugation methods to determine the interaction mechanism of Cu2＋,Fe3＋ and EPS during bioleaching chalcopyrite.Generally,Cu2＋ ions can stimulate bacteria to produce more EPS than Fe3＋ ions.The mass ratio of Fe3＋/Cu2＋ enclosed in EPS decreased gradually from about 4：1 to about 2：1 when the concentration of Cu2＋ ions increased from 0.01 to 0.04 mol/L.The amount of iron and copper bound together by EPS in ferrous-free 9K medium containing 1% chalcopyrite was about 2 times of that in 9K medium containing 0.04 mol/L Cu2＋ ions.It was inferred that the EPS with jarosites on the surface of chalcopyrite gradually acted as a weak diffusion barrier for Cu2＋,Fe3＋ ions transference during bioleaching chalcopyrite.采用超声-离心方法提取嗜酸氧化亚铁硫杆菌(ATCC 23270)胞外多聚物(EPS)、EPS中的Cu2+、Fe3+离子,研究生物浸出黄铜矿过程中Cu2+、Fe3+和EPS的相互作用机制。结果表明:与Fe3+离子相比,Cu2+离子可刺激细菌产生更多的EPS;当Cu2+离子浓度从0.01mol/L增加到0.04mol/L时,EPS中Fe3+/Cu2+质量比从4:1降低到2:1;从1%黄铜矿的无铁9K介质中提取的EPS中铜铁含量是从含0.04mol/LCu2+离子的9K介质中提取的量的2倍。在生物浸出黄铜矿过程中,黄铜矿表面结合黄铁钾钒的EPS层减弱了Cu2+、Fe3+离子的迁移,逐渐成为离子扩散壁垒。

关 键 词：extracellular polymeric substances iron ions copper ions BIOLEACHING CHALCOPYRITE 

分 类 号：TF811[冶金工程—有色金属冶金] TF18