Electrokinetic studies on covellite, cuprite and tenorite

Detailed electrokinetic measurements are conduct.ed on synthetic covellite, cuprite and tenorite particles. The role of potential determining ions identical to that of the particle lattice is considered in addition to usual H+ and hydroxide ions. In the case of CuS, additional charge reversals are noticed between pH ~ 2.5 and < 6.0 in addition to the usual charge reversals that occur by direct hydrolysis in the socalled region of metal ion precipitation. Interaction of protons with hydrous mineral surface and the adsorption of desorbed or exces metal ions with protonated surface sites are explained by ion exchange mechanism. Effect of reducing environment and oxidation-reduction reactions on