( 1. 中南大学 冶金科学与工程学院，长沙 410083；
2. 湖南冶金职业技术学院 冶金系， 株洲 412000)
摘 要: 采用等温溶解平衡法， 研究了Mn2+-NH＋4-SO2-4-H2O三元体系在298 K下的相平衡及其平衡液相的主要物理化学性质（密度和pH值）， 绘制了溶解度平衡相图及物化性质组成图。结果表明： 在三元体系Mn2+-NH＋4-SO2-4-H2O相图中存在3条饱和曲线、 2个共饱和点及3个纯盐结晶区。根据经验公式对平衡液相的密度进行了计算， 计算值与实验测定结果的变化趋势相一致， 但少数计算值的相对误差较大。
关键字: 水盐体系; 溶解度; 相平衡
Mn2+-NH＋4SO2-4-H2O system
（ 1. School of Metallurgical Science and Engineering,
Central South University, Changsha 410083, China;
2. Metallurgical Department, Hunan Metallurgical and
Professional Institute, Zhuzhou 412000, China）
Abstract: The solubility and physicochemical properties of solution, such as density and pH value, were studied in the ternary system of Mn2+-NH＋4-
SO2-4-H2O at 298 K by isothermal equilibrium method. According to the experimental data and calculated ones, the phase diagram and density-composition and pH-composition curves of the system were plotted. The results show that in the ternary system of Mn2+-NH＋4-SO2-4-H2O, there exist three saturated curves, two co-saturated points and three purity salt crystal areas. The density values were calculated by the experimental formulas and were also measured. The calculated values are not all in agreement with the experimental results.
Key words: salt-water system; solubility; phase equilibrium
