Computational Fluid Dynamic (cfd) Simulation of Fluid Flow in a Mixer-settler Extractor for Rare Earth Metal Separation

Computational fluid dynamic (CFD) simulation is an effective research approach for understanding velocity fields used in process and equipment intensification. It was found that mixer-settler used in rare earth metal extraction process was unsatisfying in large amount of liquid backlogged, high energy consumption and longtime settling process. In this paper, CFD simulations and experiment validation were carried out to study the flow field in a mixer-settler for rare earth metal separation with analysis of the effect of stirring intensity and feed rate on mixing process. Results show that large area of low velocity appears at the corner of mixer and could not be dispelled by the increase of impeller speed. Flow rate has little impact on the flow field in mixer and the agitation of the impeller has low efficiency, especially at the top of mixer. Furthermore, the effect of internal components on flow field in the mixer was analysed, such as four baffles and a plate covered on the top of mixer. Results show that flow field changes not only in magnitude but also in flow pattern. Further researches need to be carried out to test the improvement of flow fields in mixer.