Solubility and crystallization kinetics of NH4Cl in Water-Ethylene glycol binary systems
Ammonium chloride (NH 4 CI) finds extensive applications across numerous sectors such as chemicals, pharmaceuticals, and agriculture, necessitating enhancement in the quality of crystal products and precision in designing the NH 4 CI crystallization process. In this paper, we conducted an investigation into the solubility and supersolubility of NH 4 CI in H 2 O-Ethylene Glycol(EG) binary system with various proportions via dynamic laser method. We utilized the Apelblat model, Van’t Hoff model, and Redlich-Kister model to correlate the experimental findings, and derived thermodynamic parameters through these correlations. Further, we determined the solid-liquid surface tension and crystal surface entropy factor of NH 4 CI in the system using the Mersmann equation and Barata equation, thereby providing essential input for understanding crystallization kinetics. Afterward, we meticulously examined the crystallization kinetics of NH₄Cl in the H₂O-EG solvent by utilizing the batch dynamic approach. We established equations that correlated the rates of crystal nucleation and growth obtained through regression analysis. Additionally, we explored in - depth the effects of supersaturation and suspension density on the crystallization kinetics of NH₄Cl. Our results reveal that the dissolution of NH 4 CI in the binary solvent system under different proportions takes place as a non-spontaneous endothermic process, and importantly, the Redlich-Kister model appears to offer a superior comprehension of the solubility of NH 4 CI. An increase in supersaturation and stirring rate augments both the growth and nucleation rates, while an increase in suspension density elevates the nucleation rate. These research findings are expected to be advantageous for those designers involved in the industrial crystallization process of NH₄Cl.
危险品化学品经营许可证（带存储）