A COMPREHENSIVE EMPIRICAL CORRELATION FOR PREDICTION OF SUPERSOLUBILITY AND WIDTH OF THE METASTABLE ZONE IN CRYSTALLIZATION

Prediction of supersolubility and the width of the metastable zone has been a major concern among the workers in the field of industrial crystallization. Operation of crystallizers under the optimum supersaturation low enough to attain the desired product quality (Median Particle Size, Crystal Size Distribution (CSD), Shape, Purity) being one motif. The inherent relationship between the subject and the most fundamental concepts of crystallization being the other. Studying the conditions of primary homogenous nucleation and the crystal growth kinetics has been conducted for a wide range of inorganic materials. A simple probabilistic term called chance of having the desirable species congregation, has been introduced to account for the effect of solution composition. A semi-empirical model has been developed for occasions where primary homogenous nucleation occurs at a specified undercooling rate (0.2 o C/hr). The model has been found to satisfy the experimental results obtained for 28 inorganic systems under various conditions. Theconcept may be equally applicable in nucleation of organic materials and for cases where liquid nuclei (such as rain droplets) are formed.