The nucleation process and crystallization kinetics of KCl were studied in order to investigate the problems in KCl production in Qarhan salt lake. The correlation between particle size and KCl crystal growth rate was studied in a continuous mixed-suspension mixed-product removal (MSMPR) crystallizer. Classical theory of primary nucleation was used to study the homogeneous and heterogeneous nucleation mechanism of I(Cl crystallization. Several size-independent growth models and size-dependent growth models, such as Bransom, C-R, MJ2, ASL, and MJ3, were examined by the population balance theory. Results showed that MJ3 model closely fitted the experimental data, the mean relative deviation was 0.94%, the crystal growth rate G=2068 {1-exp[-1.081 x 10-5(L+961.882)]}. (C) 2009 Elsevier B.V. All rights reserved.