微紫青霉菌菌株GXCR对低品位黄铜矿中的Cu和Fe的生物淋滤及其淋滤机制

Cu and Fe bioleaching in Low-grade Chalcopyrite and Bioleaching Mechanisms Using Penicillium janthinellum Strain GXCR

摘要:

研究了Penicillium janthinellum菌株GXCR对低品位黄铜矿中的Cu和Fe的生物淋滤浸出。结果表明摇浸淋滤效率优于静置浸没淋滤效率, 对Cu的淋滤浸出效果最佳; 在添加最佳碳(10%蔗糖, W/V)、氮源(1.5% NaNO3; W/V)、摇浸淋滤和最佳条件组合(淋滤培养基初始pH 6.0, 矿石大小200目, 矿石浓度5% (W/V)和初始接种菌量3.0×105分生孢子/mL)时, Cu的浸出率达到87.31% (W/W); 摇浸淋滤时影响Cu的生物浸出的主要因素是淋滤培养基初始pH (F>F0.05); 对Cu和Fe淋滤起主要作用的有机酸分别是柠檬酸和草酸; 浸没淋滤效率低是与柠檬酸和草酸产量低有关; GXCR的生物淋滤机制有2种: 柠檬酸和草酸的生化作用和体附着生长所产生机械压力对矿石的破碎作用。

Abstract:

Bioleaching of Cu and Fe in low-grade chalcopyrite using Penicillium janthinellum strian GXCR was studied. As a result, shaking bioleaching was more efficient than submerged bioleaching; Cu bioleaching was much better than Fe bioleaching; under conditions of optimum carbon source (10% sucrose, W/V), optimum nitrogen source (1.5% NaNO3, W/V), shaking bioleaching and the optimum combination of conditions (initial pH 6.0 in leaching media, 5 % (W/V) 200–mesh ore and initial inocula of 3.0×105 conidia/mL), Cu bioleaching efficiency reached 87.31% (W/W). One of the most important factors affecting Cu bioleaching in shaking bioleaching was the initial pH in leaching media (F> F0.05). The major organic acids for Cu and Fe bioleaching were citric and oxalic acids, respectively. Low bioleaching efficiency by submerged bioleaching was due to low production of citric and oxalic acids. The mechanisms employed by the GXCR in Cu bioleaching included biochemical functions of citric and oxalic acids as well as ore crack caused by mechanical power generated from mycelial growth.