Optical luminescence studies of the xanthate adsorption layer at the solid–liquid interface

In this paper, we propose optical luminescence as a method for the evaluation of the kinetics of adsorption processes to calculate the time required to achieve the dynamic balance of the thin layers formed at the mineral–xanthate solution interface. The method is based on the measurement of the intensity for the integral optical radiation obtained from the mineral–xanthate thin layer, which is stimulated with a monochromatic pulsating optical signal, as a function of time. The luminescence was studied for the galena, sphalerite and chalcopyrite minerals with sodium amyl and sodium isobutyl xanthates, for different concentrations of the solutions and different pH values under constant temperature. Using the said method, information was gained on the kinetics of the adsorption of xanthates. Good correlation with the sequential (radiometric) investigation methods was noticed. A better measurement of the time to achieve equilibrium in the formation of the adsorption layer was also obtained. (paper)