三元体系K_2B_4O_7-KBr-H_2O在298K的相平衡研究  

A study on equilibrium solubilities and properties of solutions in the ternary system K_2B_4O_7-KBr-H_2O at 298K

作　　者：桑世华[1] 殷辉安[1] 倪师军[1] 张成江[1] 

机构地区：[1]成都理工大学材料与化学化工学院,成都610059

出　　处：《成都理工大学学报（自然科学版）》2006年第4期414-416,共3页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：国家自然科学基金资助项目(40303010);四川省教育厅自然科学基金资助项目(2004C020)

摘　　要：采用等温溶解平衡法研究了三元体系K2B4O7-KBr-H2O在298 K时的相平衡关系及平衡液相的主要物化性质(密度,电导率,pH值)。研究发现:该三元体系为简单共饱和型,无复盐及固溶体形成,根据溶解度数据绘制了相图。该体系298 K相图有2条单变度曲线,一个共饱点,相图中单变量曲线所对应的平衡固相分别为:K2B4O7.4H2O,KBr。绘制了物化性质组成图,并简要讨论了物化性质的变化规律。This paper studies the solubilities and properties （density, electrical conductivity and pH） of the solution in the ternary system K2B4O7-KBr-H2O at 298 K by the isothermal equilibrium method. Based on the solubility data, the phase diagram of the ternary system is plotted. It consists of two univariant curves and one eutectic point. The phase equilibrium solids are potassium borate （K2B4O7 · 4H2O） and potassium bromide （KBr）. Potassium bromide （KBr） has a relatively high concentration and a strong salting-out effect on potassium borate. A diagram of the properties and concentration of solution is constructed. It can be seen from the diagram that the equilibrium solution density values and electrical conductivity values increase apparently with the rise of potassium bromide （KBr） concentration, reaching the maximum values at eutectic point. The pH values, however, fall down with the rise of potassium bromide （KBr） on the whole. The results of experiments for the solution are discussed simply.

关 键 词：水盐体系 相平衡 硼酸钾 澳化钾 

分 类 号：O642.42[理学—物理化学]