交互四元体系Li^+,K^+//CO_3^(2-),B_4O_7^(2-)-H_2O298K相关系及平衡液相物化性质的研究  

A Study on the Phase Equilibrium and Solution Properties of the Quaternary System Li^+,K^+//CO_3^(2-),B_4O_7^(2-)-H_2O298K

作　　者：曾英[1] 肖霞[1] 殷辉安[1] 唐明林[1] 魏贤华[1] 

机构地区：[1]成都理工大学材料与生物工程学院,四川成都610059

出　　处：《高校化学工程学报》2002年第6期591-596,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金项目(49773200#);国土资源部"九五"重点学科生长点基金项目。

摘　　要：针对西藏扎布耶盐湖卤水组成,用等温溶解平衡法研究了四元体系Li+,K+//CO32-,B4O72--H2O 298K时的溶解度,测定了该体系的物化性质(密度、粘度、pH值、电导率、折光率)。该四元体系298K时的相图由5条溶解度单变量线、4个结晶区及2个共饱点组成。4个结晶区分别对应于盐Li2CO3、K2CO3 3/2H2O、Li2B4O7 3H2O及K2B4O7 4H2O。2个共饱点中,一个为Li2CO3、K2CO3 3/2H2O及K2B4O7 4H2O三盐共饱点,另一个为Li2CO3、Li2B4O7 3H2O及K2B4O7 4H2O的三盐不相称共饱点。体系属四元水合物相图Ⅰ型,四种原始组份间未形成复盐或固溶体。应用Pitzer电解质溶液理论拟合了Li2CO3、K2CO3、Li2B4O7和K2B4O7的单盐参数及有关的混合离子作用参数,在此基础上计算了该四元体系298K时的溶解度,计算值与实验值基本吻合。The phase equilibrium and physicochemical properties(density, refractive index, viscosity, conductivity and pH value) of the quaternary system Li+,K+//CO32-,B4O72--H2O corresponding to the composition of the brine in Zabuye saline lake, Tibet, China, were studied at 298K using the isothermal method. The isothermal solubility diagram of the quaternary system consists of five univariant curves, two invariant points, and four crystallization regions for Li2CO3, K2CO3?.5H2O, Li2B4O7?H2O and K2B4O7?H2O. One of the invariant point is incongruent point, saturated with Li2CO3, K2CO3?.5H2O and K2B4O7?H2O, and the other is congruent point, saturated with Li2CO3, Li2B4O7?H2O and K2B4O7?H2O. This system is of hydrate type Ⅰ, no complex salt or solid solution was formed among the four initial composition. Pitzer抯 theory of aqueous electrolyte solutions was used for solubility calculating. Using solubility data of ternary sub-system, the single salt parameters of Li2CO3, K2CO3, Li2B4O7 and K2B4O7, the solubility product of each solid phase being in equilibrium with the related solution, and the corresponding ion-interaction parameters qij and yijk were fitted with the multiple linear regression method. Using the fitted parameters, the solubilities for the quaternary system were predicted. The calculated solubilities basically garee with the experimental values.

关 键 词：交互四元体系 锂盐 碳酸盐 硼酸盐 相平衡 溶解度 盐湖 

分 类 号：O642.42[理学—物理化学] TS31[理学—化学]