This study explores the influences of external iron ions on the dissolution behavior of covellite minerals at different temperatures. External iron ions can significantly accelerate covellite dissolution. The copper extraction of acid covellite leaching was less than 5%, while the addition of external iron ions (ferric or ferrous ions, Fe³⁺/Fe²⁺) effectively enhanced covellite dissolution. Covellite copper extraction with 0.1 mol/L Fe²⁺ was 25% at 303 K and 40% at 318 K after 18 days, and for leaching systems with 0.1 mol/L Fe³⁺, it was approximately 40% at 303 K and 60% at 318 K. The dissolution process of covellite with external iron ions can be divided into two stages. The dissolution kinetics at the first stage are controlled by the chemical reaction between iron ions and covellite, as the generated elemental sulfur has not yet blocked the covellite surface. Compared with ferrous ions, ferric ions further increase the dissolution rate of covellite, which is also suggested by the scanning electron microscopy analysis results. Additionally, Fe³⁺ accelerates the release of copper ions by effectively reducing the particle size of covellite. In the second stage (copper extraction >40%), the reaction kinetics shift to the mixed control of the surface chemical reaction with iron ions and diffusion due to the accumulation of an elemental sulfur layer on the surface. Although Fe²⁺ cannot directly oxidize covellite, the electron exchange between Fe²⁺ and oxygen is improved through the covellite mineral, which is attributed to its metallic properties. Then, the ferric ions generated in the above process gradually corrode covellite. In addition, the temperature rise can significantly accelerate the oxidation reaction process of iron ions with covellite by forming a more porous corrosive structure. Finally, leaching bacteria (Acidithiobacillus caldus and Leptospirillum ferriphilum) are proved to boost copper extraction from covellite by transforming Fe²⁺ into Fe³⁺ and eliminating surface elemental sulfur passivation. However, dense passivation layers inevitably form on the covellite surface at the end of bioleaching, which passivates the subsequent dissolution process.

这项研究探讨了外部铁离子对不同温度下velevelite矿物溶解行为的影响。外部铁离子可显着加速金缕石溶解。酸性共沸物浸出的铜提取率不到5％，而外部铁离子（铁或亚铁离子，Fe ³⁺ / Fe ²⁺）的添加有效地提高了共沸物的溶解。18天后，使用0.1 mol / L Fe ^2+的Covellite铜萃取率在303 K时为25％，在318 K时为40％，对于使用0.1 mol / L Fe ^3+的浸出系统，在303 K时约为40％，在318 K时约为60％。Covellite与外部铁离子的溶解过程可分为两个阶段。第一阶段的溶解动力学受铁离子与玄武岩之间的化学反应控制，因为生成的元素硫尚未阻塞玄武岩表面。与亚铁离子相比，三价铁离子进一步提高了钴铝矾石的溶解速度，这在扫描电子显微镜分析结果中也可以看出。另外，Fe ³⁺通过有效地减少covellite的粒径来加速铜离子的释放。在第二阶段（铜萃取率> 40％），由于元素硫层在表面的积累，反应动力学转移到表面化学反应与铁离子和扩散的混合控制。尽管Fe ²⁺不能直接氧化covellite，但通过covellite矿物可以改善Fe ²⁺与氧之间的电子交换，这归因于其金属性能。然后，在上述过程中产生的三价铁离子逐渐腐蚀金缕石。此外，温度升高可通过形成更具多孔性的腐蚀结构来显着加速铁离子与Covellite的氧化反应过程。最后，浸出细菌（事实证明，通过将Fe ²⁺转化为Fe ³⁺并消除了表面元素硫的钝化作用，可将酸度硫杆菌和费氏钩端螺旋体（Leptospirillum ferriphilum）促进从铜铝矿中提取铜。然而，在生物浸出结束时，密云石表面不可避免地会形成致密的钝化层，从而钝化了随后的溶解过程。