杂质离子对共晶冷冻结晶过程中冰晶结晶特性的影响  

Effect of impurity ions on crystallization properties of ice crystals in eutectic freeze crystallization process

作　　者：胡超群[1] 朱亮[1,2] 沙作良[1] 王彦飞[1] 杨立斌[1] 赵楠楠[1] Hu Chaoqun Zhu Liang Sha Zuoliang Wang Yanfei Yang Libin Zhao Nannan(College of Chemical Engineering and Materials Science, Tianjin University of Science ＆ Technology, Tianjin 300457, China Myande Group Limited)

机构地区：[1]天津科技大学化工与材料学院,天津300457 [2]迈安德集团有限公司

出　　处：《无机盐工业》2017年第5期25-29,共5页Inorganic Chemicals Industry

基　　金：天津市应用基础与前沿技术研究计划(重点项目)(14JCZDJC40900)

摘　　要：以硝酸钾水溶液为研究对象,考察了杂质离子对共晶冷冻结晶过程中冰晶结晶特性的影响。首先,建立并验证了共晶冷冻结晶过程冰点的测定方法,并基于Extend-UNIQUAN模型对硝酸钾体系的冰点进行模拟计算。同时考察了不同种类杂质离子对硝酸钾水溶液冰点、结晶点、以及冷冻介稳区宽度的影响,实验研究结果表明:硝酸钾水溶液中离子杂质浓度越高,冰点、结晶点的温度越低,介稳区宽度越宽;杂质离子浓度相同的硝酸钾水溶液其冰点温度随着杂质离子半径减小而减小,结晶点温度和介稳区宽度与阳离子杂质价态成反比,与阴离子杂质价态成正比。并利用基于经典成核理论所推导的介稳区宽度模型方程对实验数据进行模拟计算,模拟结果与实验值符合较好,计算得到硝酸钾水溶液的冰晶成核级数为1.46。The effect of impurity ions in potassium nitrate solution on the crystallization properties of ice crystals during the eutectic freeze crystallization was investigated.At first,the determination method of freezing point was developed and verified,and the freezing point predicted model was developed based on Extend-UNIQUAN model.With the determination method of freezing point, the influence of impurities ions on the freezing point, crystallization point, and metastable width was investigated.Resuhs showed that the higher concentrations of impurities in potassium nitrate aqueous solution,the lower temperature of freezing point and crystallization point and the wider of metastable zone.However, given the same concentrations of different impurity ions in potassium nitrate aqueous solutions, the temperature of freezing point was inversely proportional to the radius of ions.In addition, the temperature of crystallization point decreased with increase in valence of cations and decreased in valence of anions, as well as the width of metastable zone.The simulation model of metastable zone width was derived by means of the classical nucleation theory.The calculated results were in good agreement with the experimental data, and the nucleation order of ice crystal in potassium nitrate aqueous solutions was estimated to be 1.46.

关 键 词：冰晶 介稳区 硝酸钾 共晶冷冻结晶 

分 类 号：TQ131.13[化学工程—无机化工]