Wet agglomeration of powders: from physics toward process optimization

A general method to optimize a wet powder agglomeration process for achieving desired properties of granulated products is suggested. The different states of a wet powder are characterized by a cohesion function, i.e. the evolution of the torque of the stirred system as a function of the moisture content. Two different types of agglomeration behaviours are shown: Stepwise Growing Behaviour (SGB) and Continuous Growing Behaviour (CGB). The influence of various parameters such as the particle-size distribution and the wettability of the solid surface on the cohesion function are highlighted. Such functions are shown to be very helpful to define the granulation process and the properties of the granulated products, revealing a promising methodology.