Rodrigues Michael L M, Santos Guilherme H A, Leôncio Hamilton C, Leão Versiane A
Bio&Hydrometallurgy Laboratory, Department of Metallurgical and Materials Engineering, Universidade Federal de Ouro Preto, Ouro Preto, Brazil.
Front Bioeng Biotechnol. 2019 Feb 18;6:183. doi: 10.3389/fbioe.2018.00183. eCollection 2018.
Bioleaching is a mature technology, which is widely employed commercially in the leaching of primary sources of metals (ores, concentrates, and mine residues). The current work discussed the effects of aluminum sulfate additions to the growth medium, PLS recirculation and bleeding on the column bioleaching of secondary copper sulfide ores with a significant content of fluoride-containing minerals. Fluoride is toxic to bacteria at the pH of bioleaching but its toxicity may be overcome in the presence of soluble aluminum and ferric iron. Therefore, experiments were carried out in 10 × 100 cm height aerated columns, loaded with 10 kg of crushed and agglomerated copper ore and inoculated with . Initially, fluoride concentrations of up to 2.5 g/L in the pregnant leach solution were observed due to the fast dissolution of fluoride-bearing minerals. Aluminum was added to the leaching solution to reduce the Al/F ratio so that the concentration of HF (the main toxic species) was decreased, but while the total fluoride concentration was higher than that of aluminum, the bacterial population as low. Therefore, the current work emphasizes that it is possible to set up conditions to enable bioleaching even at high fluoride concentrations. Following this approach, copper extractions above 90% were achieved for a HSO consumption ranging from 128.8 to 206.1 Kg/ton.
生物浸出是一项成熟的技术，在金属原生矿源（矿石、精矿和矿山残渣）的浸出中已得到广泛的商业应用。当前的研究探讨了向生长培养基中添加硫酸铝、贫液再循环和排液对含有大量含氟矿物的次生硫化铜矿石柱式生物浸出的影响。在生物浸出的pH值条件下，氟化物对细菌有毒，但在可溶性铝和铁离子存在的情况下，其毒性可能会被克服。因此，实验在10×100厘米高的曝气柱中进行，柱中装入10千克破碎并团聚的铜矿石，并接种了……。最初，由于含氟矿物的快速溶解，在富浸出液中观察到氟化物浓度高达2.5克/升。向浸出液中添加铝以降低铝/氟比，从而降低HF（主要有毒物质）的浓度，但当总氟浓度高于铝浓度时，细菌数量较低。因此，当前的研究强调，即使在高氟浓度下，也有可能设定条件实现生物浸出。按照这种方法，对于128.8至206.1千克/吨的硫酸消耗，铜的浸出率达到了90%以上。
