New approaches for extracting and recovering metals from mine tailings
New approaches for extracting and recovering metals from mine tailings
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DOI：
10.1016/j.mineng.2016.10.008
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发表时间：
2017-05-15
影响因子：
4.8
通讯作者：
Johnson, D. Barrie
中科院分区：
文献类型：
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作者：
Falagan, Carmen;Grail, Barry M.;Johnson, D. Barrie
金属开采产生的废料，如矿物尾矿，往往含有大量潜在有价值的金属，特别是在许多历史作业中，用于浓缩目标矿物的浮选技术的效率不如目前可用的浮选技术。制定了两阶段矿物浸出和金属回收方案，以从目前在西班牙和塞尔维亚运营的两个矿山作为废物产生的尾矿中提取铜。铜的最有效提取(84%至90%)是通过在45摄氏度下使用定义的微生物联合体来生物浸出尾矿实现的，在该微生物联合体中向尾矿中添加元素硫，并允许浸出液的pH降至接近pH 1的水平，在该点上施加厌氧条件。在此条件下，两种尾矿渗滤液中的优势菌均为耐热嗜酸硫杆菌和氧化硫硫杆菌。然后，在低pH(4.0)的生硫型生物反应器中产生的硫化氢将孕期浸出液中存在的铜以硫化物的形式沉淀出来。所使用的离线系统允许选择性地沉淀存在于偏最小二乘法中的铜，而不需要调节偏最小二乘法的pH值，尽管存在于偏最小二乘法中的少量银来自与硫化铜共沉淀的一个尾矿样品。实验数据还表明，可以使用一种简单的化学萃取剂从生物浸出的固体残留物(最常见的地方)中提取银。结果表明，对这些废物进行生物处理将具有经济和环境效益。(C)2016年提交人。爱思唯尔有限公司出版。
Waste materials from metal mining, such as mineral tailings, often contain significant amounts of potentially valuable metals particularly where, as in many historic operations, the efficiency of flotation technologies used to concentrate target minerals was not as good as those currently available. A two-stage mineral leaching and metal recovery protocol was developed to extract copper from tailings generated as waste materials in two mines currently operating in Spain and Serbia. The most effective extraction of copper (84 to >90%) was achieved by bioleaching the tailings at 45 degrees C, using a defined microbial consortium, where elemental sulfur was added to the tailings and the pH of leach liquors allowed to fall to similar to pH 1, at which point anaerobic conditions were imposed. The thermo-tolerant acidophiles Acidithiobacillus caldus and Sulfobacillus thermosulfidooxidans emerged as the dominant bacteria present in both tailings leachates under these conditions. Copper present in the pregnant leach solutions (PLS) produced were next precipitated as a sulfide phase using hydrogen sulfide generated in a low pH (4.0) sulfidogenic bioreactor. The off-line system used allowed the copper present in PLS to be precipitated selectively without the need to adjust the pH of the PLS, though small amounts of silver present in PLS from one of the tailings samples co-precipitated with copper sulfide. Experimental data also suggested that it would be possible to extract silver from bioleached solid residues (where it was mostly found) using a simple chemical extractant. The results suggested that bio-processing these waste materials would have economic as well as environmental benefits. (C) 2016 The Authors. Published by Elsevier Ltd.