三元水盐体系冰点共晶点温度与溶液组成的关系

The relationship betweenfreezing point,eutectic point and the composition of solution in ternary salt-water system

文章研究了三元水盐体系溶液的冰点共晶点与溶液组成的关系。针对三个常见的基础三元水盐体系K^+∥Cl^-、NO_3^--H_2O,K^+∥Cl^-、SO_4^(2-)-H_2O和Na^+、K^+∥SO_4^(2-)-H_2O,测定了不同组成下的溶液冰点温度,结合冰盐共晶点,构筑了体系相图冰点面,并通过数学拟合,研究了其形态;借助Matlab软件,建立了上述体系冰点共晶点温度的计算公式。结果表明:冰点共晶点温度与溶液组成呈二次曲面关系;所获得的冰点共晶点计算公式的计算结果与实验值吻合较好。为研究低温条件下的水盐溶液相态变化提供了依据。

In this paper,the relationships between freezing points,eutectic pointsand compositions of solutions of ternary salt-water systems,such as K^＋∥Cl^-,NO_3^--H_2O,K^＋∥Cl^-,SO4^2--H_2O and Na^＋,K^＋∥SO4^2--H_2O,have been investigated. The freezing points of these systems have been measured; combining eutectic points,the freezing point surfaces of these systems were constructed,and studied by Matlab software; the formula of predicting the freezing points and eutectic points were obtained. The results show： the relationships between freezing points,eutectic pointsand compositions of solutions are quadric surface; the predictedfreezing points and eutectic points are in good agreement with the experimental ones. This work provides guidance for studying the phase change of the ternary salt-water system at low temperature.