嗜酸菌作用下黄铜矿表面铁/硫形态转化对其表面钝化的影响和机理研究

Microbially mediated mineral dissolution is a kind of widespread mineral-microbe interaction, including bioleaching of chalcopyrite by acidophiles which plays an important role in many aspects. During bioleaching of chalcopyrite, the passivation layers, formed by aggregation of intermediate products onto the mineral surface, lead to the low leaching rate. Although more studies have observed leaching products relating to passivation layers, the impacting mechanism of passivation is rarely involved, especially the correlation of passivation to leaching process and the microbial iron/sulfur activity. Therefore, the project is to research the iron/sulfur speciation transformation on the surface of chalcopyrite dissolved by acidophiles and mechanism of its impact on surface passivation. On the basis of a variety of means, such as high-resolution spectroscopy, the iron/sulfur speciation transformation and microbial iron/sulfur activity, as well as the impact of environmental parameters will be studied during bioleaching of chalcopyrite, to establish the relation between iron/sulfur speciation and bioleaching efficiency, and elucidate the relatedness and mechanism among surface passivation, microbial iron/sulfur activity and chalcopyrite dissolution pathway. It is expected by this study to provide theoretical and experimental basis of abating passivation and optimizing the industrial bioleaching process of chalcopyrite.

微生物活动促进矿物的分解是一种广泛存在的矿物-微生物作用，其中嗜酸菌作用下黄铜矿的分解是一种典型的生物浸出作用，并具有多方面的重要意义。黄铜矿生物浸出过程中，反应产物可聚集在矿物表面并阻碍其持续分解，造成表面钝化。尽管诸多研究都提到钝化现象并检测到与钝化有关的产物，但钝化制约机制很少涉及，尤其是钝化效应与浸矿菌铁/硫氧化活性及黄铜矿浸出途径的相关性和机理研究缺乏。因此，本项目立题研究嗜酸菌作用下黄铜矿表面铁/硫形态转化对其表面钝化的影响和机理。拟采用多种高分辨光谱学等手段，深入研究黄铜矿生物浸出过程中矿物表面的铁/硫赋存形态和浸矿菌的铁/硫氧化活性及其受环境因素的影响，建立铁/硫赋存形态与黄铜矿生物氧化分解之间的制约关系，探明黄铜矿钝化现象与浸矿菌铁/硫氧化活性及黄铜矿浸出途径的相关性和机制。为寻找合适条件与方法以减弱钝化现象及优化黄铜矿生物浸出工艺提供理论和实验依据。