Collect. Czech. Chem. Commun. 1993, 58, 259-266

The Effect of Ethyl Xanthogenate on the Electrokinetic Properties and Surface Free Energy of Galena

M. Espinosa-Jiméneza, A. Hayas-Barrúa and F. González-Caballerob

a Department of Applied Physics, Faculty of Experimental Sciences of Jaen, Jaen, Spain
b Department of Applied Physics, Faculty of Sciences, University of Granada, 18071, Granada, Spain


An experimental investigation is described on the zeta potential and surface free energy of the system galena/potassium ethyl xanthogenate. The behavior of the zeta potential of galena with different electrolytes and with pH is also showed. The potential of zero charge of galena was found to be at pH 4.8. The negative zeta potential, obtained from electrophoretic measurements of the galena/ethyl xanthogenate system, increased with the increasing concentration of this compound in solution. This shows that the adsorption of the ethyl xanthogenate onto galena is the responsible of the above mentioned increase of the zeta potential of the system. The uptake of -S- group of ethyl xathogenate by the oxidized products existing on the galena surface could be the cause of the increase in the negative electric charge of the interface. The surface free energy of galena and their dispersion and nondispersion components have been obtained from the contact angle measurements of both water and diiodomethane liquid drops, onto galena previously treated with different concentrations of xanthogenate in solution. While the dispersion component of the surface free energy of galena increases weakly with the concentration of the ethyl xanthogenate in solution, the nondispersion component has a significant decrease with it. therefore, the increasing hydrophobicity of the galena can be correlated with the increase in the zeta potential of this mineral, which is due to the adsorption of the collector.