Towards a unified theory of wet agglomeration

Abstract

Size control in granulation is of great importance yet is often difficult to achieve. While numerical and analytical models have previously been reported there is still no comprehensive model to describe wet agglomeration systems. In this paper the basis for a new analytical solution towards predict limiting granule size is suggested. The focus of the model is on bulk behaviour of the granules where the interactions in the granular bulk after the initial contact between agglomerating granules continues to affect the properties, such as in high-shear granulation as well as flow processes such as pan or drum agglomeration. The model as developed assumes that granule size is limited by both saturation and dynamic interactions, and matches the results in the literature regarding the final and continuous growth behaviour in those systems where the model is appropriate. Based on the factors that limit the size, granule growth behaviour can be predicted as a consequence of consolidation. The model matches the behaviour of systems captured by classical growth regime maps in a more quantitative manner, and should allow improved scaling as the model develops.