Solid–liquid phase equilibria in the quinary system Na+, K+, Mg2+//Cl-, NO3-–H2O and its subsystem at 258 K
Solid–liquid phase equilibria in the quinary system Na+, K+, Mg2+//Cl-, NO3-–H2O and its subsystem at 258 K
复制标题
258 K 下五元体系 Na 、 K 、 Mg2 //Cl-、NO3-→H2O 及其子系统的固液相平衡
DOI：
10.1007/s10953-020-00978-0
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发表时间：
2020
影响因子：
1.2
通讯作者：
He Huang
中科院分区：
文献类型：
--
作者：
Xueying Wang;Xueli Huang;Xuefeng Wang;Zeyan Sun;Qinglong Luo;He Huang
采用等温溶解平衡法在258 K下研究了四元体系Na⁺、K⁺、Mg²⁺//Cl⁻ - H₂O和五元体系Na⁺、K⁺、Mg²⁻//Cl⁻、NO₃⁻ - H₂O的相平衡。根据测量数据绘制了相图。在258 K时，四元体系和五元体系中均发现了复盐KCl·MgCl₂·6H₂O。在四元体系Na⁺、K⁺、Mg²⁺//Cl⁻ - H₂O中，有两个不变点、五条单变曲线和四个结晶区。饱和有NaCl·2H₂O的五元体系包含四个不变点、九条单变曲线以及六个分别对应于KCl、NaNO₃、KNO₃、Mg(NO₃)₂·6H₂O、KCl·MgCl₂·6H₂O和MgCl₂·8H₂O的结晶区。Mg(NO₃)₂·6H₂O和MgCl₂·8H₂O具有较高的浓度，对其他盐有较强的盐析作用。因此，低温预处理可以根据当前卤水处理工艺减少复盐存在的需求，为卤水的处理提供一种替代方法，并且对于分离出更纯净的产品至关重要。
The phase equilibrium of quaternary system Na＋, K＋, Mg2＋//Cl–H2O and quinary system Na＋, K＋, Mg2＋//Cl, NO3–H2O were investigated at 258 K using isothermal dissolution equilibrium method. The phase diagrams were obtained based on the measured data. Double salt KCl·MgCl2·6H2O was found in the quaternary and the quinary systems at 258 K. In the quaternary system Na＋, K＋, Mg2＋//Cl–H2O, there are two invariant points, five univariant curves, and four crystallization fields. The quinary system saturated with NaCl·2H2O contains four invariant points, nine univariant curves, and six crystallization fields corresponding to KCl, NaNO3, KNO3, Mg(NO3)2·6H2O, KCl·MgCl2·6H2O and MgCl2·8H2O. Mg(NO3)2·6H2O and MgCl2·8H2O have higher concentration and stronger salting-out effect on other salts. Therefore, the low-temperature pretreatment can offer an alternative way for the treatment of brines in accordance with the necessity for current brine treatment processes to reduce the presence of double salts and be crucial for more pure products to be separated.