Interaction mechanism of Cu²⁺, Fe³⁺ ions and extracellular polymeric substances during bioleaching chalcopyrite by Acidithiobacillus ferrooxidans ATCC2370

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• 作者：Run-lan YU ; ^{yrl715@sina.com} ; Jing LIU ; An CHEN ; Dai-li ZHONG ; Qian LI ; Wen-qing QIN ; Guan-zhou QIU ; Guo-hua GU
• 关键词：extracellular polymeric substances ; iron ions ; copper ions ; bioleaching ; chalcopyrite
• 刊名：Transactions of Nonferrous Metals Society of China
• 出版年：2013
• 出版时间：January, 2013
• 年：2013
• 卷：23
• 期：1
• 页码：231-236
• 全文大小：872 K

文摘

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.