三元体系KCl–KBr–H_2O 323K相平衡理论计算

Phase Equilibrium of a KCl–KBr–H_2O Ternary System at 323 K

根据三元体系KCl–KBr–H_2O相平衡实验数据,回归了该体系中K（Cl,Br）固溶体的组成和平衡液相组成对应的二次方程,对固溶体组成的计算值和实验值进行了对比讨论,计算值的偏差范围在0.36%~3.31%;应用文献报道的Pitzer方程参数与温度的关联方程计算了323 K时该三元体系中盐的Pitzer方程单盐参数,并拟合了该三元体系中固溶体K（Cl,Br）和溴盐关联的活度积。在此基础上应用Pitzer方程和粒子群算法（PSO）,对323 K时三元体系KCl–KBr–H_2O的溶解度数据进行理论计算,并用计算出的溶解度数据绘制出该三元体系323 K时的相图,计算结果表明,溶解度的理论计算值与实验值吻合好。

The relationship between solid solution K（Cl,Br）composition and equilibrium liquid composition of a KCl–KBr–H_2O ternary system at 323 K was fitted based on the solubility data, and the calculated results were compared with the experimental data. The results show that the relative deviation of the calculated data varies from 0.36% to 3.31%. Single salt parameters of KCl and KBr at 323 K were calculated via correlation of Pitzer equation and temperature. Activity products（Q） of the solid solution salt K（Cl,Br） were evaluated using the Pitzer＇s model and the particle swarm optimization（PSO） algorithm based on the solubility data of the ternary system KCl–KBr–H_2O at 323 K. The relationship between activity product of K（Cl,Br） and the mole fraction of each bromine salt are given and a phase diagram of the ternary system is plotted. The results show that the calculated solubility results agree well with the experimental data.