This work presents population balance modeling to predict representative drop sizes and drop size distributions in dispersions of dilute phosphoric acid in a mixture of n-paraffin, tributyl phosphate, and di-2-ethyl hexyl phosphoric acid (D2EHPA) created in a continuous-flow stirred tank agitated with a top-shrouded pump-mix impeller having four trapezoidal blades. The stirred tank has been assumed to be homogeneous. Three population balance models, differing in droplet breakage rate models, have been evaluated. A part of the experimental data has been used to obtain the optimum values of the parameters of all the three models. The remaining part of the experimental data has been used to compare the models for their ability to predict the representative drop diameters and the number probability density distributions. On the basis of this comparison, the best model has been identified.