Modeling of strontium chloride hexahydrate growth during unseeded batch cooling crystallization by two-dimensional population balance equation

Abstract

In this study, the growth of strontium chloride hexahydrate during unseeded batch cooling crystallization was investigated and modeled by the two-dimensional population balance equation. The results suggested that in a well-mixed crystallizer, no obvious agglomeration and breakage were observed. The initial supersaturation and cooling rate were the key factors of crystal growth and the crystals grew following a size dependent mechanism. Thus, the growth of SrCl₂·6H₂O was modeled as a function of supersaturation, temperature, and crystal size. The calculated crystal size and size distribution showed good agreement with the experimental values, proving that the model could well predict the growth behavior of SrCl₂·6H₂O in the system. This study not only fills the research vacancy of SrCl₂·6H₂O crystallization, but also contributes to the optimal design of the crystallization process, aiming at preparing SrCl₂·6H₂O crystals with a larger size and a narrower size distribution.