Chalcopyrite dissolution in ferric sulfate media at ambient conditions is slow. The addition of iodide has been found to significantly improve chalcopyrite leaching in the potential range where triiodide (I) or diiodine (I) is the predominant species. In the iodine-assisted chalcopyrite leaching process, elemental sulfur was proposed to be the form of sulfur product while iron precipitation was also observed. Given the potential impact of elemental sulfur and iron precipitates on chalcopyrite leaching, this study analyzed the solid leach residues collected from the iodine-assisted chalcopyrite leaching using different solid characterization techniques. The X-ray diffraction analysis of the bulk residues shows that elemental sulfur was the product of chalcopyrite leaching and that pyrite was unreactive. The cross-sectional analysis by a mineral liberation analyzer (MLA) shows that thick layers of jarosite and elemental sulfur coated the surfaces of the solid particles. Further analysis by X-Ray photoelectron spectroscopy (XPS) with a depth resolution of <10 nm confirmed that elemental sulfur was formed and that the formation of jarosite was favored at 40 and 45 °C. Despite the formation of elemental sulfur and iron precipitates, a near complete dissolution of chalcopyrite could be achieved. Further research is required to understand how the presence of iodine changes chalcopyrite leaching in such a way that surface passivation does not occur.

中文翻译：

---

硫酸铁介质中碘辅助黄铜矿浸出固体浸出残渣的表征


在环境条件下，黄铜矿在硫酸铁介质中的溶解是缓慢的。已发现，在三碘化物 (I) 或二碘 (I) 为主要物质的潜在范围内，添加碘化物可显着改善黄铜矿浸出。在碘辅助黄铜矿浸出过程中，元素硫被认为是硫产物的形式，同时也观察到铁沉淀。鉴于元素硫和铁沉淀物对黄铜矿浸出的潜在影响，本研究使用不同的固体表征技术分析了从碘辅助黄铜矿浸出中收集的固体浸出残留物。大量残渣的 X 射线衍射分析表明，元素硫是黄铜矿浸出的产物，而黄铁矿不发生反应。矿物释放分析仪 (MLA) 的横截面分析表明，固体颗粒的表面覆盖着厚厚的黄钾铁矾和元素硫层。通过深度分辨率 <10 nm 的 X 射线光电子能谱 (XPS) 进行的进一步分析证实，形成了元素硫，并且在 40 和 45 °C 时有利于黄钾铁矾的形成。尽管形成了元素硫和铁沉淀物，但黄铜矿几乎完全溶解。需要进一步的研究来了解碘的存在如何改变黄铜矿浸出，从而不发生表面钝化。