Batch Crystallization of KCl: the Influence of the Cooling and Mixing Rate on the Granulometric Properties of Obtained Crystals

The influence of the intensity of mixing (100-500 rpm) and three different cooling rates on crystallization kinetics of KCl and granulometric properties of produced crystals has been investigated on a laboratory scale batch crystallizer. Different process conditions result with different crystal size distribution and crystal shapes. Obtained results show that cooling rate influences the supersaturation rate more intensively, the kinetics curves, and the average crystal size. On the other hand, crystal habit changes more with the intensity of agitation. Crystal size distribution can be expressed by log-normal distribution, i.e. its characteristic parameters, d 5 0 and a. Population density of crystal nuclei and overall linear growth rate are evaluated from crystal size distribution. The influence of cooling rate on both quantities (n°, L) is more intense than the influence of mixing rate.