NaBr-CaBr_(2)-H_(2)O和KBr-CaBr_(2)-H_(2)O三元体系273.15 K相平衡实验及计算  

Experiment and calculation of phase equilibrium in ternary systems NaBr-CaBr_(2)-H_(2)O and KBr-CaBr_(2)-H_(2)O at 273.15 K

作　　者：张学平[1,2] 崔瑞芝 桑世华[1] ZHANG Xueping;CUI Ruizhi;SANG Shihua(College of Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu 610059,Sichuan,China;College of Chemical&Chemical Engineering,Sichuan University of Arts and Science,Dazhou 635000,Sichuan,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,Qinghai,China)

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059 [2]四川文理学院化学化工学院,四川达州635000 [3]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海西宁810008

出　　处：《化工学报》2021年第9期4479-4486,共8页CIESC Journal

基　　金：国家自然科学基金项目(41873071,41903051);青海省自然科学基金项目(2020-ZJ-970Q)。

摘　　要：采用等温溶解平衡法对两个三元体系NaBr-CaBr_(2)-H_(2)O和KBr-CaBr_(2)-H_(2)O在273.15 K下的固液相平衡关系进行了研究,测定了相关盐在水溶液中的溶解度,绘制其等温相图。结果表明,两个三元体系均为水合物型,即平衡固相中未发现任何复盐及固溶体。两个三元体系在273.15 K下的等温相图均由一个共饱点、两条等温溶解度曲线、两个平衡固相结晶区组成。三元体系NaBr-CaBr_(2)-H_(2)O在273.15 K的两个结晶区的平衡固相分别为NaBr·2H_(2)O和CaBr_(2)·6H_(2)O,NaBr·2H_(2)O的结晶区远大于CaBr_(2)·6H_(2)O。三元体系KBr-CaBr_(2)-H_(2)O在273.15 K的两个结晶区的平衡固相分别为KBr和CaBr_(2)·6H_(2)O,KBr的结晶区远大于CaBr_(2)·6H_(2)O。基于Pitzer模型,运用已报道的Pitzer参数对所研究的两个三元体系在273.15 K下的等温溶解度进行模拟计算,其计算结果与实验结果基本吻合。The relationship of solid-liquid phase equilibrium in the two ternary systems NaBr-CaBr_(2)-H_(2)O and KBr-CaBr_(2)-H_(2)O were conducted at 273.15 K by using the isothermal dissolution equilibrium method.The results show that the two ternary systems are of hydrate type.That is,there is absence for double salt and solid solution identified in the equilibrium solid phase.The isothermal phase diagrams of the two ternary systems NaBr-CaBr_(2)-H_(2)O and KBr-CaBr_(2)-H_(2)O at 273.15 K are composed of an invariant point,two isothermal dissolution curves,and two equilibrium solid phase crystallization regions.The equilibrium solid phases of the ternary system NaBr-CaBr_(2)-H_(2)O in the two crystallization regions at 273.15 K are NaBr·2H_(2)O and CaBr_(2)·6H_(2)O,respectively,and the crystallization region of NaBr·2H_(2)O is much larger than that of CaBr_(2)·6H_(2)O.The equilibrium solid phases of the ternary system KBr-CaBr_(2)-H_(2)O in the two crystalline regions at 273.15 K are KBr and CaBr_(2)·6H_(2)O,respectively,and the crystalline region of KBr is much larger than CaBr_(2)·6H_(2)O.Based on the Pitzer model,the reported Pitzer parameters are used to calculate the isothermal solubility of the two ternary systems studied at 273.15 K,and the calculated results are basically consistent with the experimental results.

关 键 词：相平衡 溶解度 溴化钙 PITZER模型 

分 类 号：O642[理学—物理化学]