Crystallization of Calcium Carbonate: Modeling Thermodynamic Equilibrium, Pathway, Nucleation, Growth, Agglomeration, and Dissolution Kinetics with the Presence of Mg²⁺, Ba²⁺, and Sr²⁺

Calcium carbonate (CaCO 3 ) crystallization is a complex operation due to the diverse thermodynamic and kinetic factors involved during the particle formation of vaterite, aragonite, and calcite. This article involves the experimental and computational study of CaCO 3 crystallization in the presence of Mg 2+, Ba 2+, and Sr 2+ . Crystallization experiments were performed varying the Mg 2+, Ba 2+, and Sr 2+ concentration, monitored by dynamic light scattering, scanning electron microscopy, and X-ray diffractometry techniques. The crystallization model includes the thermodynamic equilibrium, pathway, and kinetic rates associated with a populational balance. It was obtained that the Mg 2+ inhibited vaterite nucleation and accelerated its transformation to calcite. The Ba 2+ and Sr 2+ ions accelerate both calcite growth and vaterite-calcite transformation rates. All external ions produced an increase in crystal size and a decrease in the total crystalline mass, albeit in different proportions. Simulation results with the developed model presented a good agreement with experimental data with an error of 12% per variable. Thus, the proposed model framework may be helpful for the evaluation of the calcium carbonate crystallization process as a practical tool to provide insight into the extensively experimentally studied effects of external ions on CaCO 3 crystal populations.