Isothermal Evaporation of Quaternary System Li^＋, K^＋, Mg^2＋//Cl^--H2O at 348K  

作　　者：LI Jiajia ZENG Ying WANG Chun YU Xudong 

机构地区：[1]College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, P. R. China [2]Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, Chengdu 610059, P. R. China

出　　处：《Chemical Research in Chinese Universities》2014年第4期676-680,共5页高等学校化学研究（英文版）

基　　金：Supported by the National High Technology Research and Development Program of China（No.2012AA061704）, the National Natural Science Foundation of China（No.41173071）, the Sichuan Youth Science and Technology Innovation Research Team Funding, China（2013TD0005） and the Innovation Team of Chengdu University of Technology, China （No.KYTD21405）.

摘　　要：The solubilities of the quaternary system Li^＋,K^＋,Mg2^＋//Cl^--H2O were investigated at 348 K via isothermal evaporation.The densities and refractive indices of its equilibrated solution were also determined experimentally.On the basis of the obtained data,the metastable phase diagram,the water content diagram,the diagrams of the density and refractive index against the composition of this quaternary system were constructed.The quaternary system Li^＋,K^＋,Mg^2＋//Cl^--H2O at 348 K belongs to a complex type with the formation of two carnallite double salts,which are potassium carnallite（K-carnallite） and lithium carnallite（Li-carnallite）.There are five salts like potassium chloride （KCl）,lithium chloride monohydrate（LiCl.H2O）,bischofite（MgCl2·6H2O）,K-carnallite（KCl·MgCl2·6H2O） and Li-carnallite（LiCl·MgCl2·7H2O）,seven unvariant curves named AH3,BH2,CH3,DH1,EH1,H1H2 and H2H3,and three invariant points,namely H1,H2 and H3,included in this metastable phase diagram.Comparisons between the stable phase diagram at 298 K and metastable phase diagram at 348 K of this quaternary system show that all the crystalline forms of the salts are not changed,whereas the crystallization areas of salts are changed significantly with temperature.The scope of KCl crystallization increases from 82% to 95% and that of K-carnallite decreases from 15.80% to 0.32% along with the temperature increasing from 298 K to 348 K,respectively.The solubilities of the quaternary system Li^＋,K^＋,Mg2^＋//Cl^--H2O were investigated at 348 K via isothermal evaporation.The densities and refractive indices of its equilibrated solution were also determined experimentally.On the basis of the obtained data,the metastable phase diagram,the water content diagram,the diagrams of the density and refractive index against the composition of this quaternary system were constructed.The quaternary system Li^＋,K^＋,Mg^2＋//Cl^--H2O at 348 K belongs to a complex type with the formation of two carnallite double salts,which are potassium carnallite（K-carnallite） and lithium carnallite（Li-carnallite）.There are five salts like potassium chloride （KCl）,lithium chloride monohydrate（LiCl.H2O）,bischofite（MgCl2·6H2O）,K-carnallite（KCl·MgCl2·6H2O） and Li-carnallite（LiCl·MgCl2·7H2O）,seven unvariant curves named AH3,BH2,CH3,DH1,EH1,H1H2 and H2H3,and three invariant points,namely H1,H2 and H3,included in this metastable phase diagram.Comparisons between the stable phase diagram at 298 K and metastable phase diagram at 348 K of this quaternary system show that all the crystalline forms of the salts are not changed,whereas the crystallization areas of salts are changed significantly with temperature.The scope of KCl crystallization increases from 82% to 95% and that of K-carnallite decreases from 15.80% to 0.32% along with the temperature increasing from 298 K to 348 K,respectively.

关 键 词：SOLUBILITY CARNALLITE Underground brine 

分 类 号：O642.42[理学—物理化学] TS352[理学—化学]