四川某低品位尾矿中铜、锌硫化物生物浸出研究

为了回收四川某铜矿浮选尾矿中的铜和锌, 以In-bac为浸矿菌种, 进行微生物浸出。考察了接种量、矿浆浓度、初始Fe²⁺浓度、浮选药剂(T-207和H-406)等因素对浸出效果的影响。结果表明, 采用两阶段微生物浸出工艺, 尾矿中铜、锌浸出效果较好, 第一阶段微生物浸出最佳条件为：接种量10%、矿浆浓度80 g/L、初始Fe²⁺浓度1.5 g/L, 尾矿中铜离子和锌离子浸出率分别为21.67%和79.67%, 此浸渣再次调浆后, 采用改进型无铁9K培养基, 无接种细菌微生物浸出, 当初始pH值为2.0、矿浆浓度为80 g/L、初始Fe²⁺浓度为0 g/L, 尾矿中铜浸出率达到36.97%, 锌浸出率为92.37%, 浸出率分别提高了15.30个百分点和12.70个百分点。浮选药剂T-207和H-406均对尾矿微生物浸出有不利影响。

Bioleaching of Copper and Zinc Sulphides in a Low-grade Tailings from Sichuan Province

In order to recover copper and zinc from flotation tailings in a Sichun copper plant, test was conducted on bioleaching of sulphides with In-bac. The effects of amount of inoculum, pulp density, initial concentration of Fe²⁺ and flotation reagents (T-207 and H-406 ) on bioleaching of tailings were investigated. Results showed that two-stage bioleaching process led to better leaching rates for both copper and zinc. In the first stage, the extraction rates of copper and zinc from tailings were 21.67% and 79.67%, respectively, with the amount of inoculum at 10%, pulp density at 80 g/L and initial concentration of Fe²⁺ at 1.5 g/L. In the second stage, the obtained residue was bioleached with no bacteria inoculated to the bioleaching system, with an initial pH value at 2.0, pulp density at 80 g/L, initial concentration of Fe²⁺ at 0 g/L, resulting in the leaching rates of copper and zinc from tailings reaching 36.97% and 92.37%, respectively, up by 15.30 and 12.70 percentage points. It is found that flotation reagents, T-207 and H-406, have negative effects on the bioleaching of copper and zinc sulphides from a low-grade tailings.