Fractal formation description of agglomeration in low shear mixer

Three raw granular materials: kaolin, microcrystalline cellulose, and calcium phosphate, usually used in various industrial areas, are wetted and mixed independently with distilled water. Agglomeration in a low shear mixer is then analyzed. The measurements of agglomerates granulometric (d25, d50 and d75) and hydro-textural (solid volume fraction, saturation degree and water content) parameters resulting from the wetting/mixing process are carried out. The later are plotted on a phase diagram, called the hydro-textural diagram. This study brings complementary information about the traditional description of agglomeration: (i) the first stage of nucleation represents that during which the fractal growth patterns (the nuclei) are built, (ii) the second stage of growth by coalescence was proven to conform to a fractal structuring behaviour. In low shear conditions, this experimental observation contradicts the classical description of agglomeration insofar as no consolidation phenomena are observed during coalescence.