Sánchez-Andrea Irene, Stams Alfons J M, Weijma Jan, Gonzalez Contreras Paula, Dijkman Henk, Rozendal Rene A, Johnson D Barrie
Laboratory of Microbiology, Wageningen University, Stippeneng 4 6708 WE Wageningen, the Netherlands
Laboratory of Microbiology, Wageningen University, Stippeneng 4 6708 WE Wageningen, the Netherlands CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
FEMS Microbiol Lett. 2016 Jun;363(11). doi: 10.1093/femsle/fnw106. Epub 2016 Apr 18.
The metal mining industry faces many large challenges in future years, among which is the increasing need to process low-grade ores as accessible higher grade ores become depleted. This is against a backdrop of increasing global demands for base and precious metals, and rare earth elements. Typically about 99% of solid material hauled to, and ground at, the land surface currently ends up as waste (rock dumps and mineral tailings). Exposure of these to air and water frequently leads to the formation of acidic, metal-contaminated run-off waters, referred to as acid mine drainage, which constitutes a severe threat to the environment. Formation of acid drainage is a natural phenomenon involving various species of lithotrophic (literally 'rock-eating') bacteria and archaea, which oxidize reduced forms of iron and/or sulfur. However, other microorganisms that reduce inorganic sulfur compounds can essentially reverse this process. These microorganisms can be applied on industrial scale to precipitate metals from industrial mineral leachates and acid mine drainage streams, resulting in a net improvement in metal recovery, while minimizing the amounts of leachable metals to the tailings storage dams. Here, we advocate that more extensive exploitation of microorganisms in metal mining operations could be an important way to green up the industry, reducing environmental risks and improving the efficiency and the economy of metal recovery.
未来几年，金属采矿业面临诸多重大挑战，其中之一是随着易开采的高品位矿石逐渐枯竭，处理低品位矿石的需求日益增加。这一情况是在全球对贱金属、贵金属和稀土元素需求不断增长的背景下出现的。目前，通常运往地表并在地表研磨的固体物料中约99%最终会成为废物（排土场和尾矿）。这些废物暴露于空气和水中常常会导致形成酸性的、受金属污染的径流，即所谓的酸性矿山排水，这对环境构成严重威胁。酸性排水的形成是一种自然现象，涉及各种嗜岩石营养型（字面意思为“食岩石”）细菌和古生菌，它们会氧化还原态的铁和/或硫。然而，其他能还原无机硫化合物的微生物基本上可以逆转这一过程。这些微生物可用于工业规模，从工业矿物浸出液和酸性矿山排水中沉淀金属，从而在提高金属回收率的同时，将尾矿储存坝中可浸出金属的量降至最低。在此，我们主张在金属采矿作业中更广泛地利用微生物可能是使该行业更加环保的重要途径，既能降低环境风险，又能提高金属回收的效率和经济性。
