Rb^(+)(Cs^(+)),Mg^(2+)//SO_(4)^(2-)-H_(2)O三元体系273.2 K固液相平衡研究  

Solid-Liquid Phase Equilibria in the Aqueous Ternary System Rb^(+)(Cs^(+)),Mg^(2+)//SO_(4)^(2-)-H_(2)O at 273.2 K

作　　者：俞章法 曾英 李学群[1,2] 贺玉华 吕欣欣 于旭东 YU Zhangfa;ZENG Ying;LI Xuequn;HE Yuhua;LÜXinxin;YU Xudong(CITIC Guoan Industrial Group Co.,Ltd.,Beijing,100020,China;Key Laboratory of Comprehensive Utilization of Sulfate Salt Lake Resources,Golmud,816000,China;College of Materials and Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu,610059,China)

机构地区：[1]中信国安实业集团有限公司,北京100020 [2]硫酸盐型盐湖资源综合利用青海省重点实验室,青海格尔木816000 [3]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《盐湖研究》2024年第5期35-41,共7页Journal of Salt Lake Research

基　　金：中信集团十大科技创新项目(2023ZXKYA05100);国家自然科学基金项目(U1607121)。

摘　　要：为了获取铷镁、铯镁共存硫酸盐体系在273.2 K下各盐结晶的形式,文章采用等温溶解平衡法、Schreinemakers湿渣法,结合X射线粉晶衍射开展了在273.2 K下三元体系Rb^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O和Cs^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O固液相平衡研究。结果表明,两个三元体系在273.2 K时均为复杂体系,分别生成拥有较大结晶相区的复盐Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O和Cs_(2)SO_(4)·MgSO_(4)·6H_(2)O,即铷镁、铯镁共存硫酸盐体系在273.2 K下铷铯不易单独析出。多温对比结果表明,三元体系Rb^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O在273.2、298.2和308.2 K时均生成Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O、Rb_(2)SO_(4)和MgSO_(4)·7H_(2)O,且复盐Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O的结晶区均最大,单盐Rb2SO4的结晶区均最小,三个结晶区均随温度升高而增大。三元体系Cs^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O在273.2、298.2和308.2 K均有三个结晶区(Cs_(2)SO_(4)·MgSO_(4)·6H_(2)O>MgSO_(4)·7H_(2)O>Cs_(2)SO_(4)),随着温度的升高,三个结晶区均略有减小。In order to determine the crystalline forms of in the rubidium-magnesium and cesiummagnesium coexisting sulfate system at 273.2 K,the isothermal dissolution method combined with Schreinemakers method and X-ray powder diffraction was used to conduct the solid-liquid phase equilibria studies of two ternary systems Rb^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O and Cs^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O at 273.2 K.The results indi‐cate that these two ternary systems are both complex systems at 273.2 K,each forming a double salt with large crystallization region,namely Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O and Cs_(2)SO_(4)·MgSO_(4)·6H_(2)O,which means that rubidium and cesium are not easily precipitated and separately in the coexisting sulfate system of Rb^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O and Cs^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O.Comparative results at multiple temperatures show that the ter‐nary system Rb^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O at 273.2,298.2 and 308.2 K consistently forms Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O,Rb_(2)SO_(4) and MgSO_(4)·7H_(2)O.The crystallization region of the double salt Rb_(2)SO_(4)·MgSO_(4)·6H_(2)O is the larg‐est,while that of salt Rb_(2)SO_(4) is the smallest,with all three crystallization regions increasing as the tempera‐ture rises.For the ternary system Cs^(+),Mg^(2+)//SO_(4)^(2-)-H_(2)O has three crystalline regions at 273.2,298.2 and 308.2 K(Cs_(2)SO_(4)·MgSO_(4)·6H_(2)O>MgSO_(4)·7H_(2)O>Cs2SO4),and these areas slightly decrease as the tem‐perature rises.

关 键 词：相平衡 硫酸铷 硫酸铯 复盐 

分 类 号：O642.42[理学—物理化学]