三元体系Li2SO4-MgSO4-H2O在273.15K时介稳相平衡  

Metastable equilibria of ternary system Li_2SO_4-MgSO_4-H_2O at 273. 15 K

作　　者：李栋婵[1,2] 王士强[2] 

机构地区：[1]河北工业大学海水资源高效利用化工技术教育部工程研究中心,天津300170 [2]天津科技大学海洋科学与工程学院天津市海洋资源与化学重点实验室,天津300457

出　　处：《化学工程》2014年第1期37-39,44,共4页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(20936003);天津市应用基础与前沿技术研究计划项目(12JCQNJC03400);天津市海洋资源与化学重点实验室开放基金资助项目(201202)

摘　　要：采用等温蒸发法,测定了三元体系Li2SO4-MgSO4-H2O在273.15 K时介稳平衡的溶解度和液相的物化性质(密度和折光率)。根据实验数据绘制了相应的介稳相图和物化性质-组成图。研究结果表明:该三元体系有1个共饱点(Li2SO4·H2O+MgSO4·7H2O),2条单变量溶解度曲线,2个单盐结晶区:Li2SO4·H2O,MgSO4·7H2O,其中MgSO4·7H2O的结晶区域较大。该体系属简单共饱型,无复盐及固溶体产生。介稳平衡溶液的物化性质密度、折光率随溶液中MgSO4含量的变化而有规律变化,并且在共饱点处有最大值。采用经验公式预测了该体系介稳平衡溶液的密度和折光率,预测值与实验值吻合较好。The solubilities and the physicochemical properties （density and refractive index） of the ternary system Li2SOa-MgSOn-H20 at 273.15 K were determined by isothermal evaporation method. According to the experimental data, the metastable equilibrium phase diagram and the physicochemical properties vs. composition diagram were plotted. The experimental results of the metastable equilibria show that there is one eutectic point for （Li2SO4 ·H20 ＋ MgSO4· 7H20）, two univariant curves, and two crystallization regions corresponding to the large area of epsomite （MgSO4·7H20） and the relative small area of lithium sulphate monohydrate （Li2SO4 · H20）. The system belongs to a simple co- saturated type, and neither double salt nor solid solution was found. It also indicates that the physieochemical properties of the metastable equilibrium solution are in regular changes with the change of sulfate ion concentration, and achieve the maximum values at the invariant point in the system. The calculated values of densities and refractive indices in the quaternary system by the empirical equations agree well with the experimental values.

关 键 词：介稳相平衡 等温蒸发 硫酸锂 硫酸镁 

分 类 号：O642.42[理学—物理化学]