Abstract In order to tackle the dual challenge of utilizing highly refractory chalcopyrite (CuFeS2) while saving scarce freshwater resources, this study aimed to systematically understand the individual role of chemical lixiviant and bioleaching microorganisms in the complex Fe3+-Cu2+-SO42−-Cl− chalcopyrite leaching system. In general freshwater bioleaching conditions, the Eh level sharply increased, and the “high-Eh-bioleaching” became the major leaching driving force. In this case, the lowest Cu yield was obtained. The chalcopyrite leaching reaction responded differently to different salinity levels. At a low salinity of 0.5% NaCl, chemical Cl−-leaching effect resulted in a higher Cu yield than the fresh-water “high-Eh-bioleaching” system. The growth of tested microbes was observed at 0.5% NaCl, but partial deactivation of microbial Fe-oxidation suppressed the Eh level. Under this condition, synergism between the chemical Cl−-leaching effect and the “low-Eh-bioleaching” effect was found. At a high salinity of 2% NaCl, on the other hand, no active cell growth was observed, and thus pre-grown cells were used to mimic the presence of Cl−-tolerant cells. Chemical Cl−-leaching readily proceeded at 2% NaCl at low Eh, but quickly ceased upon the depletion of H+. The presence of bioleaching cells somewhat slowed down the speed of chemical Cl−-leaching, but the acid depletion was alleviated by microbial acid generation. Chemical Cl−-leaching, which favors low Eh condition, was the main driving force for chalcopyrite leaching at 2% NaCl. Therefore, the activity of Cl−-tolerant S-oxidizer alone, rather than mixed Fe- and S-oxidizing consortium, was shown to play a critical role in maximizing the chalcopyrite dissolution.

中文翻译：

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生物浸出微生物在黄铜矿精矿盐水浸出中的作用

摘要 为了应对利用高难熔黄铜矿 (CuFeS2) 和节约稀缺淡水资源的双重挑战，本研究旨在系统地了解化学浸出剂和生物浸出微生物在复杂的 Fe3+-Cu2+-SO42−-Cl− 黄铜矿中的各自作用。浸出系统。在一般淡水生物浸出条件下，Eh水平急剧上升，“高Eh生物浸出”成为主要的浸出驱动力。在这种情况下，获得了最低的铜产量。黄铜矿浸出反应对不同盐度水平的反应不同。在 0.5% NaCl 的低盐度下，化学 Cl-浸出效应导致比淡水“高 Eh 生物浸出”系统更高的铜产量。在 0.5% NaCl 下观察到测试微生物的生长，但微生物铁氧化的部分失活抑制了 Eh 水平。在这种情况下，发现了化学 Cl− 浸出效应和“低 Eh 生物浸出”效应之间的协同作用。另一方面，在 2% NaCl 的高盐度下，没有观察到活跃的细胞生长，因此使用预生长的细胞来模拟耐氯细胞的存在。在 2% NaCl 和低 Eh 条件下，化学 Cl-浸出很容易进行，但在 H+ 耗尽后迅速停止。生物浸出细胞的存在在一定程度上减缓了化学氯 - 浸出的速度，但微生物酸的产生减轻了酸的消耗。有利于低 Eh 条件的化学 Cl-浸出是 2% NaCl 下黄铜矿浸出的主要驱动力。因此，单独的耐氯 S-氧化剂的活性，而不是混合的 Fe-和 S-氧化财团，