Variation of surface tension in aqueous solutions of sodium dodecyl sulfate in the flotation bath

A study has been carried out on the modification of surface tension in aqueous solutions of the collector sodium dodecyl sulfate (SDS), at temperature of 293 K and pH between 4 and 11. The results of this study show that the surface tension varies very slightly when pH in the medium of flotation bath is modified. The critical micelle concentration (cmc) has been identified and certain thermodynamic magnitudes associated with the adsorption of SDS in the solution–air interface were also obtained. Moreover, the values for the molecular limiting area range between 19 and 31 Å per molecule and standard adsorption energy between −19.82 and −23.52 kJ mol−1, at pH between 4 and 10.