258.15K下五元体系Na^＋,K^＋//Cl^-,SO4^2-,NO3^-―H2O相平衡研究  

Phase Equilibria of a Na^+,K^+//Cl^-,SO_4^(2-),NO_3^-―H_2O Quinary System at 258.15 K

作　　者：廖玲[1] 黄雪莉[1] 宋欢 

机构地区：[1]石油天然气精细化工教育部&自治区重点实验室,新疆大学化学化工学院,新疆乌鲁木齐830046

出　　处：《高校化学工程学报》2016年第1期7-12,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(21166022);新疆大学创新团队(培育)资助项目

摘　　要：采用等温溶解平衡法研究了258.15 K下五元体系Na^+,K^+//Cl^-,SO_4^(2-),NO_3^-―H_2O及其子体系Na^+,K^+//Cl^-,NO_3^-―H_2O的相平衡关系。测定了两个体系各盐的溶解度及溶液密度(冰相区除外),并绘制相图。研究结果表明:在258.15 K,氯化钠饱和时,该五元体系平衡干盐相图由四个两盐结晶区、五条单变量溶解度曲线和两个零变量点构成,四个两盐结晶区分别对应于Na Cl×2H_2O+Na NO_3,Na Cl×2H_2O+KNO_3,Na Cl×2H_2O+KCl,Na Cl×2H_2O+Na_2SO_4×10H_2O;与该体系298.15 K下的相图相比,K_3Na(SO_4)2和Na NO_3×Na_2SO_4×H_2O结晶区消失,Na_2SO_4×10H_2O结晶区扩大,相图大为简化;在258.15 K时,上述四元体系的平衡干盐相图由四个单盐结晶区(除冰区外)、五条单变量溶解度曲线和两个零变量点构成,四个单盐结晶区分别对应于Na NO_3、Na Cl×2H_2O、KNO_3和KCl;与该体系在298.15 K下的相图相比,硝酸钾结晶区扩大很多。The phase equilibria of a quinary system Na^＋,K^＋//Cl^-,SO4^2-,NO3^-―H2O and one of its subsystems（a quaternary system Na^＋, K^＋//Cl^-, NO3^-―H2O） were investigated by an isothermal method at 258.15 K. Solubilities and densities of the quinary system and its quaternary subsystem（except ice phase zone） were determined experimentally, and the equilibrium phase diagrams were plotted. The results show that the phase diagram of the system Na^＋,K^＋//Cl^-,SO4^2-,NO3^-―H2O saturated with Na Cl consists of five univariant curves, two invariant points and four crystallization regions corresponding to Na Cl×2H2O＋Na NO3, Na Cl×2H2O＋KNO3, Na Cl×2H2O＋KCl and Na Cl×2H2O＋Na2SO4×10H2O. Compared with the phase diagram of the quinary system at 298.15 K, the crystalline regions of the double salts（K3Na（SO4）2 and Na NO3×Na2SO4×H2O） disappeared, and the crystalline region of Na2SO4×10H2O became larger. Therefore, the phase diagram of the quinary system was greatly simplified at 258.15 K. For the Na^＋,K^＋//Cl^-,NO3^-―H2O system, the phase diagram consisted of five univariant curves, two invariant points and four crystallization regions（except ice phase zone） corresponding to Na NO3, Na Cl×2H2O, KNO3 and KCl. In addition, compared with the phase diagram of the quaternary system at 298.15 K, the crystalline region of KNO3 became larger.

关 键 词：硝酸盐 四元水盐体系 五元水盐体系 相平衡 溶解度 

分 类 号：O642.42[理学—物理化学]