XRD and Synchrotron-Based XRD Study of Chalcopyrite Leaching Catalyzed by Silver Ions

摘要

Silver ion can effectively improve the bioleaching efficiency of chalcopyrite, and the mechanism of the process is still in controversy. In this study, leaching experiments, X-ray diffraction (XRD), and synchrotron radiation X-ray diffraction (SR-XRD) were conducted to investigate the intermediate of chalcopyrite in chemical leaching and bioleaching system. In the chemical leaching system, different ratios of ferric ions to ferrous ion were adopted as the leaching reagent. L. ferriphilum was used in the bioleaching system. The leaching behaviors showed that the copper extraction was significant promoted from 39 to 96% and from 60 to 95% of chemical leaching and bioleaching system, respectively. The X-ray diffraction results show that jarosite was the main intermediate during the leaching process. However, using synchrotron radiation X-ray diffraction, idaite was also detected. Even though much jarosite still formed in the presence of silver ions, this passivation film would not hinder the leaching of chalcopyrite.