搅拌结晶器中硫酸钾的成核动力学  

Nucleation Kinetics of Potassium Sulfate in Stirred Crystallizer

作　　者：马钰蓝 郑雅元 吴谢萍 田永琪 徐梦琳 王娇 杨美会 沈栎秋 MA Yulan;ZHENG Yayuan;WU Xieping;TIAN Yongqi;XU Menglin;WANG Jiao;YANG Meihui;SHEN Liqiu(Department of Chemical Engineering,Sichuan University of Science&Engineering,Zigong 643000,China)

机构地区：[1]四川轻化工大学化学工程学院,四川自贡643000

出　　处：《化学反应工程与工艺》2024年第5期428-435,共8页Chemical Reaction Engineering and Technology

基　　金：泸州市重点实验室开放课题(HYJH-2305-B);四川省大学生创新训练项目(S202210622048)。

摘　　要：硫酸钾具有很好的水溶性和稳定的安全性能,阐明其晶体成核过程可以为控制硫酸钾晶体尺寸和质量提供指导。本工作对硫酸钾在搅拌结晶器中的成核结晶动力学进行了实验探讨,利用经典成核理论研究了硫酸钾结晶的均相和非均相成核机理,测定不同温度和过饱和比下硫酸钾的成核诱导时间,计算了不同温度及过饱和比时的晶体界面张力和成核参数,包括临界成核半径(r^(*))、临界成核自由能(ΔG^(*))、临界成核分子数(i^(*))。结果表明:当温度和过饱和比提高时,诱导时间、临界成核自由能、临界成核半径及临界分子数均减小,成核速率增大;随着温度和过饱和比的变化,晶体的形态变化可忽略不计,而平均粒径随着过饱和比的增加和温度的增大而增大,所测得的成核参数的变化规律与经典的成核理论一致。Potassium sulfate has good water solubility and stable safety performance.Elucidating its crystal nucleation process can provide guidance for controlling the size and quality of potassium sulfate crystals.In this paper,the nucleation and crystallization kinetics of potassium sulfate in a stirring crystallizer were experimentally investigated.The homogeneous and heterogeneous nucleation mechanisms of potassium sulfate crystallization were studied by using the classical nucleation theory.The nucleation induction times of K2SO4 at different temperatures and supersaturation ratios were measured,and the interfacial tension and various nucleation parameters were calculated,including the critical nucleation radius(r^(*)),the critical nucleation free energy(ΔG^(*)),and the critical number of nucleating molecules(i^(*)).The results showed that when the temperature and supersaturation ratio increased,the induction time,critical nucleation free energy,critical nucleation radius and critical molecular number decreased,while the nucleation rate increased.With changes of temperature and supersaturation,the morphological changes of the crystal could be ignored,while the average particle size increased with the increase of supersaturation and temperature.The variation pattern of the measured nucleation parameters was consistent with that of classical nucleation theory.

关 键 词：硫酸钾 成核动力学 过饱和比 搅拌结晶 

分 类 号：TQ424.2[化学工程] O647.33[理学—物理化学]