不同类型媒晶剂对硫酸铵晶体形态学指标的影响  

Effect of crystallization additives on crystal morphology of ammonium sulfate

作　　者：高毅颖[1,2] 张懿[1,2] 王静康[3] 陈巍[3] 徐红彬[1,2] 

机构地区：[1]中国科学院过程工程研究所,北京100190 [2]湿法冶金清洁生产技术国家工程实验室,北京100190 [3]天津大学化工学院,天津300072

出　　处：《化工学报》2011年第12期3575-3579,共5页CIESC Journal

摘　　要：选用硫酸铵这一物系,从实验和模拟两个角度研究了在媒晶剂作用下的结晶过程,探讨媒晶剂对晶体产品形态学指标的影响规律。利用粉末衍射仪(XRD)和扫描电镜(SEM)对晶体产品的晶体结构、形态学指标进行了测定与分析。应用分子摸拟软件Materials Studio计算媒晶剂和硫酸铵各个晶面之间的单分子结合能数值,结合能数值与其对晶面生长速率的影响具有良好的对应关系,进而确定了媒晶剂对硫酸铵晶体晶习的影响,结合硫酸铵晶体成核和生长动力学规律,推断出媒晶剂的影响机理。A series of additives were introduced to crystallization process of ammonium sulfate, and different forms of ammonium sulfate crystal were obtained. The crystallization process was studied based on experiments and computer simulation. The effect of crystallization additives on morphology of ammonium sulfate was investigated. The ammonium sulfate crystals were characterized by XRD and SEM analysis to examine crystal habit and crystal form. Materials Studio is employed to calculate molecule binding energies between additive ions and ammonium sulfate crystal surfaces. The results indicate that the values of binding energy have certain relationship with growth rates of crystal faces, which illustrates the effects of impurities and additive ions on crystal habit of ammonium sulfate. Molecule binding energy of cationic additives is higher than that of molecules. The higher valence of cationic additive is, the higher molecule binding energy is. Based on the kinetic data and molecular simulation results, the effect mechanism of different impurities on crystallization is analyzed.

关 键 词：硫酸铵 媒晶剂 晶习 分子结合能 

分 类 号：TQ026.5[化学工程]