Study on the simultaneous effect of silica nanoparticles and cetyl trimethyl ammonium bromide on drop size in mixer-settler extractor

► Simultaneous effect of SiO2 and CTAB on the mean drop size was studied. ► Addition of CTAB into system containing SiO2 led to great reduction in drop size. ► Effect of hydrodynamic parameters on sauter mean drops size was investigated. ► New correlations were suggested in order to predict the sauter mean drops size. ► Surfactant concentration was introduced into the correlations as a new parameter.