Abstract

A chalcopyrite CuFeS2 electrode obtained from the 'El Teniente' mine has been studied by Electrochemical Impedance Spectroscopy (EIS) in an alkaline solution for different oxidation potentials. The experimental results can be interpreted from a Randles equivalent circuit, V(dc)<0.4 V vs. saturated calomel electrode (SCE), and a surface layer model for V(dc)>0.4 V vs. SCE. From these results, the variation with the d.c. applied potentials of charge transfer electrical resistance of the redox reaction, the double layer capacitance and other characteristic parameters are considered. A chalcopyrite CuFeS2 electrode obtained from the `El Teniente' mine has been studied by Electrochemical Impedance Spectroscopy (ELS) in an alkaline solution for different oxidation potentials. The experimental results can be interpreted from a Randles equivalent circuit, Vdc<0.4 V vs. saturated calomel electrode (SCE), and a surface layer model for Vdc>0.4 V vs. SCE. From these results, the variation with the d.c. applied potentials of charge transfer electrical resistance of the redox reaction, the double layer capacitance and other characteristic parameters are considered.