细菌浸出黄铜矿体系中矿物化学、物相转化及其分解过程动力学特性研究

Biohydrometallurgy was in the frontier technology for extraction copper from the refractory primary copper sulphide such as chalcopyrite. The main focus is on the research of both theory and process for improving the leaching yield and rate of copper. However, the mechanism of dissolution process of chalcopyrite during the bioleaching and the corresponding kinetic was not investigated systematically, therefore, which was the research frontier aim to reveal the mechanism and the kinetic characterics of bioleaching of chalcopyrite. In this study, the chemical transformation on the surface of chalcopyrite and the phase covert would be investigated by grazing incidence X-ray diffractometry(GIXD),XPS and the in situ synchrotron PD to confirm the media production and the corresponding chemical reaction during the bioleaching of chalcopyrite. And then the kinetics of dissolution og chalcopyrite during bioleaching could be investigated to find the controlling reaction and the factors to accelerate the reaction rate. Moreover, the dissolution process of chalcopyrite during bioleaching could be described as well as the dissolution kinetic and the control reaction. The mechanism of bioleaching of chalcopyrite could be explained more complete and the new technical methods could be established to enhance the dissolution rate.

微生物冶金是难处理黄铜矿型铜矿资源高效利用的前沿技术。提高黄铜矿浸出率和浸出速度的微生物冶金理论和工艺的研究成为焦点。目前，对细菌浸出体系中黄铜矿分解过程机理以及相应的反应动力学没有系统的研究，是该领域研究的前沿，旨在探明黄铜矿的溶解机理及其动力学特性。本项目针对不同相态黄铜矿，通过采用掠角XRD、XPS、同步辐射光谱等表面分析方法，研究细菌浸出体系中黄铜矿氧化分解过程中矿物物相和化学的转化规律，查明溶解过程的中间产物及其生成顺序，确定相应的化学反应方程，揭示黄铜矿的溶解步骤，同时进行动力学分析，找出控制步骤及其影响因素，阐明黄铜矿的溶解机理和分解动力学规律。为提高黄铜矿浸出速率提供理论依据。

本项目通过黄铜矿晶体特性的研究，解析了黄铜矿元素价态的分布特性，阐明了黄铜矿晶体中Cu的氧化态为+1，表明黄铜矿的化学式可表述为Cu+Fe3+(S2−)2，揭示了黄铜矿相态转化的规律和不同相态黄铜矿基本特性，表明黄铜矿的晶体特性是决定黄铜矿浸出行为的实质性原因之一。测定了黄铜矿溶解过程的中间产物，建立了细菌浸出体系中黄铜矿氧化分解的基本过程，为黄铜矿溶解机理的研究提供了科学的数据。在此基础上，发现在本项目研究尺度上Cu2S的生成是黄铜矿溶解过程的动力学控制步骤，体系的低电位420±20 mV vs. SCE是控制步骤的关键动力学参数，使黄铜矿的浸出速率提高了1倍以上。本项目研究成果获得湖南省科技进步一等奖，是该奖的主要创新点之一。