High shear granulation of dolomite – I: Effect of shear regime on process kinetics

Abstract

Wet granulation of previously unreported formulation system is presented. Dolomite powder is granulated under different shear regimes by using three-component binder formulation, water-molasses-polyvinylpyrrolidone. 1-D discretized population balance equation (PBE) and Equi-Partition of Kinetic Energy (EKE) coalescence kernel are applied to modelling granulation in a high shear mixer. Process modelling is focused to simulation of changes of the property of a group of entities, granule size distribution (GSD). The GSD predictions indicate the presence of coalescence growth as a dominant mechanism in the dolomite granulation process. Minor deviations between simulated and real GSDs signify the probability of other granulation mechanism(s) existence. A posteriori approach by integral method was used for coalescence rate constant estimation. This research highlights discrepancy in the coalescence rate of dolomite granulation process, between its early and later stages. Moreover, kinetic analysis of the high shear granulation process provides quantification of the macroscopic variable (impeller speed) influence on regarded property of a group of granules in terms of values of growth rate parameter.