Characterization of intermediate sulfur layer during acidic oxidation of chalcopyrite using electrochemical impedance spectroscopy (EIS) and atomic force microscope (AFM)

摘要

The utilization of Electrochemical ImpedanceSpectroscopy (EIS) in conjunction with Atomic ForceMicroscopy (AFM) is a powerful surface characterizationtechnique to study the role of sulfur formation during acidicoxidation of chalcopyrite. It has been established that thechalcopyrite dissolution kinetics is controlled by the formationof passive sulfur layer during leaching. The objective of thestudy was to characterize the intermediate sulfur layerformation at different oxidation conditions in acidic solution.The chalcopyrite samples were subjected to anodic oxidationand the oxidation process was analyzed using impedancespectroscopy. The sulfur growth on the chalcopyrite surfaceduring oxidation was further analyzed using Atomic ForceMicroscope for sulfur roughness and grain size, peak height and sulfur growth.