Electrochemistry of oxidation of chalcocite in the presence and absence of microorganisms

Abstract

The electrochemical behavior of the chalcocite oxidation process in the presence and absence of microorganisms was investigated using electrochemical techniques, including cyclic voltammetry, anodic polarization curves, Tafel curves, and X-ray photoelectron spectroscopy (XPS) analysis. The research results prove the stepwise dissolution mechanism of chalcocite in the presence and absence of microorganisms. The initial stage of oxidation is initiated at low redox potentials. During the initial stage, the intermediate products of CuxS (1 ≤ x via XPS. The XPS analysis results show that the components of the passivation layer on the electrode surface are complex, including CuS, polysulfide (Sn2-), elemental sulfur (S0) and intermediate oxidation products that contain sulfate (SO42-) and that CuS is the main passivating component; therefore, the oxidation of chalcocite follows the multisulfur method.

Keywords

• chalcocite
• electrochemistry
• bioleaching
• passivation
• polysulfide