Extraction of copper from an oxidized (lateritic) ore using bacterially catalysed reductive dissolution
Extraction of copper from an oxidized (lateritic) ore using bacterially catalysed reductive dissolution
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DOI：
10.1007/s00253-014-5687-6
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发表时间：
2014-07-01
影响因子：
5
通讯作者：
Johnson, D. Barrie
中科院分区：
文献类型：
--
作者：
Nancucheo, Ivan;Grail, Barry M.;Johnson, D. Barrie
在酸性还原条件下，采用嗜酸性嗜化性细菌氧化亚铁硫杆菌的纯培养和混合培养，在pH和温度控制的搅拌反应器中，对含铜0.8%的氧化红土矿石进行了生物浸出。硫是细菌的电子供体，针铁矿(矿石中主要的铁矿物)中的铁铁是电子受体。与好氧培养或无菌缺氧反应器相比，细菌催化还原溶解红土所浸出的铜明显更多，矿石中高达78%的铜被提取出来。这包括从不易酸的矿物(主要是硅酸铜)中浸出的铜，以及与红土矿石中的铁铁矿有关的铜。在厌氧生物反应器中，浸出液中的可溶性铁以铁(II)的形式存在，铜以铜(I)的形式存在，但当反应器曝气时，这两种金属都被迅速氧化(生成铁(III)和铜(II))。添加到反应堆中的细菌数量在决定从矿石中溶解铜的速度和产量方面起着关键作用。这项工作进一步证明，还原生物处理--一种最近描述的从氧化矿床中提取贱金属的方法--有可能极大地扩大可生物利用的金属矿石的范围。
An oxidized lateritic ore which contained 0.8 % (by weight) copper was bioleached in pH- and temperature-controlled stirred reactors under acidic reducing conditions using pure and mixed cultures of the acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans. Sulfur was provided as the electron donor for the bacteria, and ferric iron present in goethite (the major ferric iron mineral present in the ore) acted as electron acceptor. Significantly more copper was leached by bacterially catalysed reductive dissolution of the laterite than in aerobic cultures or in sterile anoxic reactors, with up to 78 % of the copper present in the ore being extracted. This included copper that was leached from acid-labile minerals (chiefly copper silicates) and that which was associated with ferric iron minerals in the lateritic ore. In the anaerobic bioreactors, soluble iron in the leach liquors was present as iron (II) and copper as copper (I), but both metals were rapidly oxidized (to iron (III) and copper (II)) when the reactors were aerated. The number of bacteria added to the reactors had a critical role in dictating the rate and yield of copper solubilised from the ore. This work has provided further evidence that reductive bioprocessing, a recently described approach for extracting base metals from oxidized deposits, has the potential to greatly extend the range of metal ores that can be biomined.