Abstract

A mathematical model for the steady-state operation of a deep-layer gravity settler has been developed by using a population balance approach. This model takes into account the size distribution of drops within the dispersion band and uses rate expressions for the description of drop-drop and drop-interface coalescence phenomena. The model was validated with experimental data obtained in a laboratory mixer-settler unit, for a system consisting of 10% Acorga M5640 in Escaid 103-0.25 M Na2SO4 aqueous solution. The model successfully predicts the thickness of the dispersion band and the growth of the dispersed phase drops occurring by drop-drop coalescence within the dispersion band.