Brittle fracture in crystallization processes Part A. Attrition and abrasion of brittle solids

摘要

In chemical engineering processes in which solids are produced or handled, the strength of the substance plays a key role. The following presents a comprehensive model for one of these processes, crystallization from suspensions. When crystallizataion kinetics are determined by the formation of fragments and their subsequent growth, the developed model equations can predict the whole crystallization process in a quantitative manner. The size dependent growth behaviour of fragments is explained by the attrition process itself. The predicted influence of material propreties on the fracture behaviour of a great number of crystalline substances as well as the suggested grwoth function for attriton fragments compare well with experimental results. The model equations can be used to estimate when and how brittle fracture will occur in chemical engineering processes and, more specifically, to scale-up suspension crystallizers.