ABSTRACT

The leaching kinetics of chalcopyrite is sluggish due to the refractory nature of chalcopyrite and the formation of passive layers. In this study, the effect of mechanical activation on the leaching behavior and mechanism was studied by leaching tests, electrochemical measurements, particle size distribution analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry-thermogravimetric analysis (DSC-TGA), X-ray photoelectron spectroscopy (XPS) and electron microprobe. The results show that mechanical activation can greatly promote the chalcopyrite leaching kinetics, and the copper extraction was increased from 14.1% to 55.7% and 91.8% after primary and secondary mechanical activation, respectively. The electrochemical study results indicated that mechanical activation did not change the cathodic reactions kinetics, however, the anodic dissolution kinetics was significantly promoted. XRD and DSC-TGA results show that mechanical activation treatment can effectively activate chalcopyrite due to the grain size reduction, formation of crystal defects and lattice deformation. The main solid product of chalcopyrite leaching is elemental sulfur. Besides particle size reduction, the reduction of grain size, formation of crystal defects and lattice deformation can increase the strain energy and instability of chalcopyrite, which plays an important role in improving chalcopyrite leaching kinetics.

摘要

由于黄铜矿的难熔性质和钝化层的形成，黄铜矿的浸出动力学缓慢。本研究通过浸出试验、电化学测量、粒度分布分析、扫描电子显微镜（SEM）、X射线衍射（XRD）、差示扫描量热法-热重分析等方法研究了机械活化对浸出行为和机理的影响。 (DSC-TGA)、X 射线光电子能谱 (XPS) 和电子微探针。结果表明，机械活化能极大地促进黄铜矿的浸出动力学，一次和二次机械活化后铜的提取率分别从14.1%提高到55.7%和91.8%。电化学研究结果表明，机械活化并未改变阴极反应动力学，但显着促进了阳极溶解动力学。XRD和DSC-TGA结果表明，机械活化处理可以有效地活化黄铜矿，原因在于晶粒尺寸减小、晶体缺陷的形成和晶格变形。黄铜矿浸出的主要固体产物是元素硫。除了粒径减小外，晶粒尺寸的减小、晶体缺陷的形成和晶格变形等都会增加黄铜矿的应变能和不稳定性，这对改善黄铜矿的浸出动力学具有重要作用。XRD和DSC-TGA结果表明，机械活化处理可以有效地活化黄铜矿，原因在于晶粒尺寸减小、晶体缺陷的形成和晶格变形。黄铜矿浸出的主要固体产物是元素硫。除了粒径减小外，晶粒尺寸的减小、晶体缺陷的形成和晶格变形等都会增加黄铜矿的应变能和不稳定性，这对改善黄铜矿的浸出动力学具有重要作用。XRD和DSC-TGA结果表明，机械活化处理可以有效地活化黄铜矿，原因在于晶粒尺寸减小、晶体缺陷的形成和晶格变形。黄铜矿浸出的主要固体产物是元素硫。除了粒径减小外，晶粒尺寸的减小、晶体缺陷的形成和晶格变形等都会增加黄铜矿的应变能和不稳定性，这对改善黄铜矿的浸出动力学具有重要作用。