Compared with traditional methods, computational fluid dynamics−population balance model (CFD−PBM) simulations are much more efficient for the design of extractors. In this study, the CFD−PBM framework was established for a pilot-scale rotating-disk contactor. The Euler−Euler approach incorporated with the realizable k−ε model was used for the twophase simulation. For droplet coalescence and breakage, predictive closures based on the model of Luo and Svendsen were employed for further verification. The species transport model was also solved to estimate axial mixing. The model was validated first by comparing the flow field with referenced particle image velocimetry data. Then the predicted key parameters of droplet diameter, dispersed-phase holdup, and Peclet number were compared with empirical correlations for a comprehensive validation.The results indicate that the predictive CFD−PBM is suitable for the design of extraction columns. Its average deviations on the three parameters are 15.7%, 12.9%, and 15.2%, respectively. The model also successfully predicts the regular variations of the droplet diameter and holdup with the rising agitation rate, which contribute to the validation.