不同微观形貌的半水硫酸钙脱水动力学对比  

Comparation on dehydration kinetics of calcium sulfate hemihydrate with different morphologies

作　　者：叶家兴 黄姗姗 孙玉柱[1] 陈杭[1] 宋兴福[1] YE Jiaxing;HUANG Shanshan;SUN Yuzhu;CHEN Hang;SONG Xingfu(National Engineering Research Center for Comprehensive Utilization of Salt Lake Resources,East China University of Science and Technology,Shanghai 200237,China;Qinghai Salt Lake Magnesium Industry Co.,Ltd.,Geermu 816000,Qinghai Province,China)

机构地区：[1]华东理工大学国家盐湖资源综合利用工程技术研究中心,上海200237 [2]青海盐湖镁业有限公司,青海格尔木816000

出　　处：《化学工程》2024年第12期63-69,共7页Chemical Engineering(China)

摘　　要：对比α-半水石膏、β-半水石膏、α-半水晶须3种不同形貌的半水硫酸钙晶体的热脱水动力学的差异。利用热重分析数据计算拟合三者脱水过程的动力学参数和机理函数,结果表明:3种半水硫酸钙晶体的脱水活化能分别为105.01、107.02、93.57 kJ/mol。2种短柱状的石膏相半水硫酸钙的脱水机理符合不同级数的Avrami-Erofeev方程,脱水速率受晶核的形成及生长控制。而纤维状的晶须相半水硫酸钙的脱水机理则转变为相边界反应中的收缩圆柱体模型。通过得到的动力学方程预测3种形貌的半水硫酸钙在不同温度下脱水所需时间。The differences in thermal dehydration kinetics of calcium sulfate hemihydrate crystals withα-hemihydrate gypsum,β-hemihydrate gypsum andα-hemihydrate whiskers were compared.The kinetic parameters and mechanism functions of the three dehydration processes were calculated and fitted using thermogravimetric analysis data.The results show that the dehydration activation energies of the three calcium sulfate hemihydrate crystals are 105.01,107.02 and 93.57 kJ/mol.The dehydration mechanisms of two short columnar gypsum phases of calcium sulfate hemihydrate conform to Avrami-Erofeev equations of different levels,and the dehydration rate is controlled by the formation and growth of crystal nuclei.The dehydration mechanism of the fibrous whisker phase calcium sulfate hemihydrate is transformed into a shrinking cylinder model in the phase boundary reaction.The time required for dehydration of three morphologies of calcium sulfate hemihydrate at different temperatures is predicted through the obtained kinetic equations.

关 键 词：半水硫酸钙 晶体形貌 热重分析 动力学模型 

分 类 号：TQ132.3[化学工程—无机化工]