EIS evaluation of kinetics parameters for the oxidation of galena in presence of xanthate Conference Paper uri icon

abstract

  • This work is aimed to simulate experimental impedance spectra for the anodic oxidation of galena-xanthate system at high collector concentrations. The simulations are based on a proposed kinetic model, which includes three reversible reactions at three different polarization potentials-0.3 V, 0.1 V and 0.2 V. The first part of the mechanism involves the oxidation and adsorption of xanthate, X-, at a potential of-0.3 V. The second one considers the reaction of the xanthate adsorbed on the galena surface towards the formation of dixanthogen, (X)2, and lead xanthate PbX2. Finally, the third mechanism step takes into account the evolution of PbX2 towards the formation of lead hydroxide Pb(OH)2. According to the experimental and simulated impedance spectra obtained at potentials 0.1 V and 0.2 V, the system displays an inductive loop attributed to a relaxation of the interface due to adsorption-desorption of adsorbed intermediates X ads, PbX2ads and Pb(OH)2. These results provide new findings that contribute to a better understanding of the surface modification processes taking place at the interface galena-xanthate in flotation systems. © The Electrochemical Society.

publication date

  • 2013-01-01