Advanced Heap-leaching for Chalcopyrite

堆浸法在铜生产中已变得非常重要：目前世界上超过20%的铜是通过这种方法在斑岩铜矿的露天矿中生产的。在该方法中，将低品位氧化矿和次生硫化矿中的铜萃取到硫酸溶液中，并通过溶剂萃取和电积方法回收萃取的铜。黄铜矿（CuFeS_2）是铜矿床深部的主要铜矿物，其浸出速度很慢，开发先进的堆浸方法是今后湿法炼铜的发展方向，影响黄铜矿浸出速度的因素之一是溶液中Fe^<3+>与Fe^<2+>浓度比所决定的氧化还原电位：浸出率随氧化还原电位的增加而增加，在最佳氧化还原电位处达到最大值，然后在更高的氧化还原电位处降低。本研究探讨了氧化还原电位的影响， ...更多信息 通过摇瓶浸出实验和电化学实验研究了黄铜矿浸出过程中氧化还原电位的影响因素，结果表明：黄铜矿浸出过程中最佳氧化还原电位是铜离子和亚铁离子浓度的函数。根据实验结果和浸出机理的理论分析，建立了黄铜矿浸出的计算机模拟模型，确定了黄铜矿浸出的最佳工艺条件。模拟结果与以惰性硅质岩为载体的黄铜矿粉末柱浸实验结果一致：控制溶液的化学组成和氧化还原电位，在100 d内，黄铜矿中铜的浸出率可达80%。该提取率与用于次生硫化铜的常规堆浸操作中的提取率相当，表明这里建立的氧化还原电位控制对于黄铜矿浸出是有效的。少

Heap-leaching has become important in copper production: over 20% of copper in the world is now produced at open pit mines of porphyry copper deposits through this method. In this method, copper in low-grade oxide and secondary sulfide ores is extracted into sulfuric acid solutions, and the extracted copper is recovered by solvent-extraction and electro-winning methods. However, the leaching rate of chalcopyrite (CuFeS_2), a major copper mineral in the deepest parts of the deposits, is very slow, and the development of advanced heap-leaching methods for this mineral is an object for copper hydrometallurgy in the future.One factor affecting the leaching rate of chalcopyrite is the redox potential determined by the concentration ratio of Fe^<3+> to Fe^<2+> in the solution: the leaching rate increases when increasing the redox potential to reach a maximum at an optimum redox potential, and then decreases at higher redox potentials. This study investigated the effect of redox potential con … More trol on chalcopyrite leaching rates.Shaking flask leaching experiments and electrochemical experiments were carried out to clarify factors affecting the redox potential dependence of chalcopyrite leaching, and the results indicates that the optimum redox potential is a function of the cupric and ferrous ion concentrations. Based on the experimental results and theoretical considerations of the leaching mechanism, a computer simulation model was developed and the optimum leaching conditions for chalcopyrite were determined. The simulated results agree with the results of column leaching experiments using a chalcopyrite powder sample supported on inert silica host rocks: About 80% of copper was extracted from the chalcopyrite in 100 days when the chemical composition and redox potential of solution were controlled. This extraction rate is comparable to the rate in the conventional heap-leaching operation for secondary copper sulfides, indicating that the redox potential control established here is effective for chalcopyrite leaching. Less