Control of the redox potential by oxygen limitation improves bacterial leaching of chalcopyrite.
Control of the redox potential by oxygen limitation improves bacterial leaching of chalcopyrite.
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DOI：
10.1002/bit.10184
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发表时间：
2002-05
影响因子：
3.8
通讯作者：
K. Third;R. Cord-Ruwisch;H. Watling
中科院分区：
文献类型：
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作者：
K. Third;R. Cord-Ruwisch;H. Watling
摇瓶和搅拌槽浸出实验表明，黄铜矿的浸出受铁离子浓度低至200 mg L（-1）和氧化还原电位>420 mV（vs. Ag/AgCl）的抑制。与0.1 M硫酸铁相比，在0.1 M硫酸亚铁存在下，黄铜矿（4%悬浮液，表面积2.3 m2 g（-1））的化学浸出增强了四倍。计算机控制的反应器被设计成当溶液中的氧化还原电位大于指定的设定点时，通过阻止向反应器的空气供应来起到“恒电位仪”-生物反应器的作用。在低的、恒定的氧化还原电位（380 mV vs. Ag/AgCl）下的浸出实现了52%-61%的最终铜回收率，这是用连续供应氧气（<30%提取）实现的回收率的两倍。观察到细菌种群在氧限制下继续生长，但以被发现改善黄铜矿溶解的受控方式生长。由于控制机制容易建立，并有可能降低生产成本，该技术的使用可能会在工业中得到应用。
Shake flask and stirred tank bioleaching experiments showed that the dissolution of chalcopyrite is inhibited by ferric ion concentrations as low as 200 mg L(-1) and redox potentials >420 mV (vs. Ag/AgCl). Chemical leaching of chalcopyrite (4% suspension, surface area 2.3 m2 g(-1)) was enhanced fourfold in the presence of 0.1 M ferrous sulphate compared with 0.1 M ferric sulphate. A computer-controlled reactor was designed to function as a "potentiostat"-bioreactor by arresting the air supply to the reactor when the redox potential in solution was greater than a designated setpoint. Leaching at a low, constant redox potential (380 mV vs. Ag/AgCl) achieved final copper recoveries of 52%-61%, which was twice that achieved with a continuous supply of oxygen (<30% extraction). The bacterial populations were observed to continue growing under oxygen limitation but in a controlled manner that was found to improve chalcopyrite dissolution. As the control mechanism is easily established and is likely to decrease production cost, the use of this technology may find application in industry.