AbstractA fluidized bed crystallizer is employed to investigate the effect of pH of the solution on the growth and dissolution rates of potassium chloride crystals. The growth rate shows a minimum value at the pH range between 7 and 10, whereas the dissolution rate shows a minimum at the range between 7 and 9. It is found in this study that the growth‐ and the dissolution rate of potassium chloride in the acidic solutions are higher than in the alkaline solutions. A mechanism is suggested to explain the growth kinetics based on the interaction between the different species found in the electrolyte solutio