Impacts of Surface Modification on Isotherm and Kinetics of Collector Adsorption

Surface dissolution is one of the mineral surface modification methods. In this study, the effect of surface dissolution on isotherm and kinetic of sodium oleate as a collector on the surface of ilmenite, olivine-pyroxene and quartz were investigated. Parameters of conditioning time, pH, temperature, activation energy, specific area and contact angle were studied before and after surface dissolution. The results of adsorption isotherms of Langmuir, freundlich and temkin and kinetic models of elovich, lagergerin and psedo second order showed that the collector adsorption on the minerals can be described by Langmuir isotherm and pseudo second-order kinetic model. The collector adsorption on the studied minerals is occurred based on adsorption capacity from solution and mainly single layer. The results indicated that surface dissolution result in increasing the collector adsorption on ilmenite surface and decreasing it about the gangue minerals. Also, after surface dissolution, the activation energy of ilmenite is decreased form 57255.4 J/mol to 42437.9 J/mol which indicates the collector adsorption on ilmenite is more favorable. Furthermore, after surface dissolution the activation energies of quartz and olivine-pyroxene are increased from 5746.5 J/mol to 5816.5 J/mol, and from 8326.6 J/mol to 12523.3 J/mol, respectively. The results of contact angle measurement showed that after surface dissolution the contact angle of ilmenite is increased and it is decreased for gangue minerals. These results were in good agreement with the results of Uv-Vis spectroscopy, collector adsorption and ICP analysis.