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Abstract: Mineral particles are used in many industrial applications as fillers, in coatings, as ad- and absorbers or in catalysis. In these manifold fields the particle size and shape control the final performance and properties of the minerals. Much has been published using different techniques to describe the aspect ratio of platy particles. This study describes a simple method to calculate aspect ratios for platy particles based on particle size data and specific surface area determined by nitrogen adsorption, exemplified with three different talc grades which vary in their amount of specific surface area and geological origin, as well as with one nano-sized synthetic Laponite (Laponite® RD) to illustrate the sensitivity to input parameters and their physical interpretation. The contrast between mass/volume and number probability distribution of particle size is discussed and illustrated. [Copyright &y& Elsevier]

Abstract: Mineral particles are used in many industrial applications as fillers, in coatings, as ad- and absorbers or in catalysis. In these fields the particle size and shape may control the final performance and properties of the minerals. This work aims to develop a size distribution and surface area defined particle aspect ratio for rod-like particles, using a previously discussed improvement of the input parameters to the Hohenberger model. The tested aragonite particles were shown to have an aspect ratio of ~2 determined using laser scattering particle size data and surface area data, proven by image analysis. Palygorskite showed the limitation of the current model with respect to the surface area input parameter as measured by nitrogen adsorption due to its internal porosity. An aspect ratio of 21 of the fibrous material was calculated in contrast to the value of 7 found by image analysis. The calculation procedure can thus be recommended to approximate the aspect ratio of non-porous fibrous and rod-like particles in a fast, easy and reproducible way. [Copyright &y& Elsevier]