The influence of powder properties on the imbibation rate

Mixing of powders into liquids is a common unit operation. Mixing can be divided into several steps, imbibation of the powder into the liquid being the first. Under some circumstances, such as when the powder has poor wetting properties, imbibation can be the rate-determining step. The effects of different powder properties on the imbibation rate were evaluated using an experimental imbibation model based on the imbibing process employed in an industrial powder-in-liquid mixer. A multivariate analysis of the results suggests that bulk density and capillary penetration rate, and to some extent cohesivity, play an important role in determining the powder imbibation rate. The results also suggest that the capillary penetration rate is increasing on a large particle radius, slow solubilisation of the particles and a low ability of the particles to generate viscosity. (C) 2011 Elsevier B.V. All rights reserved.