Bioleaching of Chalcopyrite Waste Rock in the Presence of the Copper Solvent Extractant LIX984N

• Published in: Frontiers in microbiology Vol. 13; p. 820052
• Main Authors: Liu, Xiaohui, Li, Yuhong, Cao, Jianfeng, Zeng, Zhenshun, Liu, Xiaorong, Zhang, Ruiyong, Li, Qian, Sand, Wolfgang
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 18.03.2022
• Subjects: Acidithiobacillusferrooxidans; bioleaching; chalcopyrite waste rock; Leptospirillum ferrooxidans; LIX984N; Microbiology; Sulfobacillus thermosulfidooxidans; Leptospirillum ferrooxidans; Acidithiobacillusferrooxidans; LIX984N; bioleaching; chalcopyrite waste rock; Sulfobacillus thermosulfidooxidans
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.820052

Heap bioleaching, the solubilization of metal ions from metal sulfides by microbial oxidation, is often combined with solvent extraction (SX) and electrowinning to recover, e.g., copper from low-grade ores. After extraction, the leaching solution is recycled, but the entrained organic solvents may be toxic to the microorganisms. Here , , and were selected to perform bioleaching of chalcopyrite waste rock in the presence of the SX reagent (2.5% v/v LIX984N in kerosene). Possibly inhibitory effects have been evaluated by copper extraction, bacterial activity, number of actively Fe(II)-oxidizing cells, and biofilm formation. Microcalorimetry, most probable number determination, and atomic force microscopy combined with epifluorescence microscopy were applied. The results show that 100 and 300 mg/L SX reagent could hardly inhibit from oxidizing Fe , but they seriously interfered with the biofilm formation and the oxidization of sulfur, thereby hindering bioleaching. was sensitive to 50 mg/L SX reagent, which inhibited its bioleaching completely. showed different metabolic preferences, if the concentration of the SX reagent differed. With 10 mg/L LIX984N preferred to oxidize Fe and extracted the same amount of copper as the assay without LIX984N. With 50 mg/L extractant the bioleaching stopped, since preferred to oxidize reduced inorganic sulfur compounds.