A copper and iron K-edge XANES study on chalcopyrite leached by mesophiles and moderate thermophiles
A copper and iron K-edge XANES study on chalcopyrite leached by mesophiles and moderate thermophiles
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DOI：
10.1016/j.mineng.2013.01.010
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发表时间：
2013-07
影响因子：
4.8
通讯作者：
Yi Yang;Weihua Liu;Miao Chen
中科院分区：
文献类型：
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作者：
Yi Yang;Weihua Liu;Miao Chen
为了揭示不同温度下黄铜矿生物氧化的机制，通过同步加速器X射线吸收近边结构（XANES）对经嗜温菌（30℃）和中嗜热菌（48℃）浸出的纯黄铜矿进行了表征。溶液研究表明，升高的温度促进了黄铜矿的溶解。在 48°C 时最终铜回收率为 41%，而在 30°C 时仅为 15%。 Cu K-edge XANES 分析表明溶解的铁多于铜，在浸出的早期阶段在颗粒表面留下类 CuSn 物质。在浸出后期，类 CuSn 物质中的铜被浸出，留下类 Sn 物质。类锡物质浸出的缓慢可能是后期没有形成类铜锡物质，从而导致黄铜矿钝化的原因。此外，Fe K-edge XANES 表明在 30°C 时没有形成大量黄钾铁矾；然而，在 48°C 时，黄钾铁矾沉淀大大加速，占第 35 天残渣中铁物质的 51%。
To reveal the mechanism of chalcopyrite biooxidation at different temperatures, pure chalcopyrite leached by mesophiles (30°C) and moderate thermophiles (48°C) was characterized by synchrotron X-ray absorption near-edge structure (XANES). Solution studies show that elevated temperatures promoted chalcopyrite dissolution. A final copper recovery of 41% was achieved at 48°C, while only 15% at 30°C. Cu K-edge XANES analyses indicated more iron than copper dissolved, leaving on the particle surface CuSn-like species in the early stages of leaching. In the late stages of leaching, copper in CuSn-like species was leached, leaving behind Sn-like species. The slowness of leaching of Sn-like species may be the reason why no CuSn-like species were formed in the late stages, and thus why chalcopyrite passivated. In addition, Fe K-edge XANES indicates no significant amount of jarosite formed at 30°C; however, at 48°C, jarosite precipitation was profoundly accelerated, which accounted for 51% of the iron species in the residue at day 35.