黄铜矿氧化浸出机理电化学基础研究

In recent years, hydrometallurgical technologies have been used extensively in the field of metal extraction from ores due to its significant advantages on high metal recovery, excellent adaptability and flexibility, and environment-friendly. With great potential to develop into practical applications, copper hydrometallurgical processes, especially those extraction technologies of oxidative leaching copper from low grade sulfide ore and/or concentrates in acidic media have been on focus in past decades. However, there are still significant disagreements on the mechanism of the oxidative leaching of primary copper sulfide minerals such as chalcopyrite, which limited the chalcopyrite hydrometallurgy process development and application. Thus, the mechanism and kinetics of oxidative leaching of chalcopyrite will be examined in detail through combined technologies of mineralogy, electrochemisty and surface chemistry in this project with the purpose to illustrate the leaching and migration behavior of three main elements Cu, Fe, and S during chalcopyrite leaching. The project will focus on fundamental aspects on the theoretical analysis and the electrochemical process of chalcopyrite leaching in acidic media under different leaching conditions. The properties, formation mechanism, and growth kinetics of the passive films on chalcopyrite surface will be studied by electrochemical methods. The effect of typical additives on chalcopyrite leaching will also be investigated. The extensive research on these critical issues will help to establish the process control system, to develop novel technologies and processes, and to provide theoretical guidance and technical support for the efficient utilization of low grade copper sulfide ore and concentrates.

湿法冶金技术因具有环境友好、回收率高和适应性强等优点，近年来在矿产资源开发领域应用越来越广。作为最有发展潜力和实际应用价值的铜矿湿法浸出技术，铜矿物酸性体系氧化浸出工艺与技术的研究与开发一直备受关注。然而目前针对酸性体系最主要的原生铜矿物黄铜矿的氧化浸出过程机理仍不明晰，限制了黄铜矿湿法冶金工艺的开发与应用。本项目以黄铜矿为研究对象，采用微观工艺矿物学、电化学和界面化学等物理化学方法，通过研究不同条件下黄铜矿氧化浸出动力学，揭示和阐明黄铜矿浸出过程主要元素组分铜铁硫的浸出行为和迁移规律；采用电化学方法，进一步研究浸出过程中钝化膜的形成机理与动力学、钝化膜的性质、以及典型添加剂对黄铜矿氧化浸出过程的作用和影响等关键科学问题，为研究开发低品位原生硫化铜矿湿法处理的新工艺新技术，实现资源高效开发提供理论指导和技术支撑。

湿法冶金技术因具有环境友好、回收率高和适应性强等优点，近年来在矿产资源开发领域应用越来越广。作为最有发展潜力和实际应用价值的铜矿湿法浸出技术，铜矿物酸性体系氧化浸出工艺与技术的研究与开发一直备受关注。然而目前针对酸性体系最主要的原生铜矿物黄铜矿的氧化浸出过程机理仍不明晰，限制了黄铜矿湿法冶金工艺的开发与应用。本项目按照申报书制定的研究计划，开展了黄铜矿在酸性体系中氧化浸出热力学和动力学研究。研究了黄铜矿在复杂硫酸体系中多相传质规律，建立多相体系反应动力学模型；通过电化学技术和手段研究黄铜矿在不同浸出条件下阴阳极反应，阐明了黄铜矿在酸性介质中氧化浸出过程的反应机理和控制机制；探讨了典型无机/有机添加剂对黄铜矿氧化浸出的作用与影响，研究了氯离子在黄铜矿硫酸浸出过程中的作用机理及Fe3+浓度对浸出动力学的影响，研究了木质磺酸盐类有机添加剂对黄铜矿浸出的作用机理；开发了在常压下能高效浸出黄铜矿的H2SO4-H2O2-乙二醇浸出工艺；研究了机械活化和微波活化等手段强化黄铜矿浸出的机理及技术可行性；研究了在线生成双氧水且同步浸出黄铜矿技术可行性，开展了黄铜矿在不同浸出条件下钝化膜的形成机理以及生长动力学研究，采用电化学方法，如循环伏安法和动电位扫描等，研究黄铜矿在不同浸出条件下的钝化膜形成规律；采用电化学阻抗谱研究在不同浸出条件下（浸出剂、温度和压力），黄铜矿表面所形成钝化膜的界面结构及其生长动力学；结合XRD，SEM和XPS等表征手段，进一步确认黄铜矿在不同浸出条件下所形成的钝化膜的化学组成与结构；研究了黄铜矿钝化膜的半导体特性，如载流子浓度及平带电位等。根据上述研究结果，针对黄铜矿难以被常压酸性浸出的问题，开发了二次机械活化浸出技术及H2SO4-H2O2-乙二醇浸出工艺，上述两种工艺方法能够在常压条件下高效浸出黄铜矿。