Determination of the characteristics of agglomerates in aqueous suspensions using nonlinear optimization

Measurement of characteristics of particles in suspensions without dilution has a practical interest in formulation, mineral processing, material sciences and environmental technologies.These characteristics are the size, shape, and surface properties of the primary particles, and also the size, structure and the number of primary particles in the agglomerates.In this work, the multiple light-scattering model through the optical analyzer, Turbiscan MA 2000 is used to determine the mean settling velocities of monodisperse glass beads and two polydisperse samples of powders, kaolin D and alumina, differing by their particle size distribution, their shape and their surface properties.Beyond the experimental validation of theoretical and empirical predictions, the nonlinear adjustment of experimental settling data gives the number of primary particles per agglomerate and the agglomerate size. These two characteristics lead to the determination of the fractal dimension of the agglomerates. The latter was found in the range of 2.5–2.7 for all suspensions examined. The calculation of permeability and spherical factor reveals the nonspherical impermeable agglomerates.

Graphical AbstractSedimentation process of suspensions is recorded using the Turbiscan MA 2000 device. It allows determining the settling velocity of particles. Nonlinear adjustment of the latter property gives the number of primary particles per agglomerate N, agglomerate radius R, its fractal dimension Df and thus most of the hydrodynamic characteristics of agglomerates.Figure optionsDownload as PowerPoint slide