Study On The Stable Equilibrum Of Subsystems Of Li⁺,Na⁺,K⁺,Ca²⁺,Sr²⁺//Cl^-- H₂O At 288K

In order to study the salt water system of Oil-field brine in Nanyishan,the stable equilibria of subsystems of the multi-system Li⁺,Na⁺,K⁺,Ca²⁺,Sr²⁺//Cl^-–H₂O were studied at 288K used isothermal dissolution method,respectively.The subsystems include five quaternary systems LiCl-KCl-SrCl₂-H₂O,LiCl-NaCl-SrCl₂-H₂O,LiCl-NaCl-KCl-H₂O,NaCl-CaCl₂-SrCl₂-H₂O and KCl-CaCl₂-SrCl₂-H₂O,and five ternary systems NaCl-SrCl₂-H₂O,KCl-SrCl₂-H₂O,LiCl-KCl-H₂O,LiCl-SrCl₂-H₂O and SrCl₂-CaCl₂-H₂O.According to the experimental data,the phase diagrams of the quaternary and ternary system,and the water content diagrams of the quaternary system were plotted.The NaCl-SrCl₂-H₂O system at 288K is simple system.The phase diagram consists of one invariant point,two univariant curves and two fields of crystallization corresponding to NaCl and SrCl₂·6H₂O.In KCl-SrCl₂-H₂O system at 288K there are neither complex salt nor solid solution formed.The phase diagram consists of one invariant point,two univariant curves and two fields of crystallization corresponding to KCl and SrCl₂·6H₂O,respectively.The ternary system LiCl-KCl-H₂O at 288K is a simple saturation system,there are neither complex salt nor solid solution formed.The phase diagram consists of one invariant point,two univariant curves and two fields of crystallization corresponding to KCl and LiCl·2H₂O.The ternary system LiCl-SrCl₂-H₂O at 288K is a simple saturation system,there are neither complex salt nor solid solution formed.The phase diagram consists of two invariant point,three univariant curves and three fields of crystallization corresponding to LiCl·2H₂O,SrCl₂·2H₂O and SrCl₂·6H₂O.The ternary system CaCl₂-SrCl₂-H₂O has solid solution formed.and its phase diagram is composed of two invariant points,three univariate curves and three crystal phase regions.The three crystallization fields correspond to the single salt SrCl₂·6H₂O,CaCl₂·6H₂O and the solid solution Ca_x(Sr_1-x)Cl₂·6H₂O.The quaternary system LiCl–KCl–SrCl₂–H₂O at 288K is a simple system,and its phase diagram is composed of two invariant points,five univariate curves and four crystal phase regions.The four crystallization fields correspond to KCl,LiCl·2H₂O,SrCl₂·2H₂O and SrCl₂·6H₂O.The quaternary system LiCl–NaCl–SrCl₂–H₂O is a simple system at 288K,and its phase diagram is composed of two invariant points,five univariate curves and four crystal phase regions.The four crystallization fields correspond to NaCl,LiCl·2H₂O,SrCl₂·2H₂O and SrCl₂·6H₂O.The quaternary system LiCl–NaCl–KCl–H₂O is a simple system at 288K,and its phase diagram is composed of one invariant points,three univariate curves and three crystal phase regions.The four crystallization fields correspond to NaCl,KCl and LiCl·2H₂O.The quaternary system NaCl-CaCl₂-SrCl₂-H₂O at 288K has solid solution formed.and its phase diagram is composed of two invariant points,five univariate curves and four crystal phase regions.The four crystallization fields correspond to the single salt NaCl,SrCl₂·6H₂O,CaCl₂·6H₂O and the solid solution Ca_x(Sr_1-x)Cl₂·6H₂O.The quaternary system KCl-CaCl₂-SrCl₂-H₂O at 288K has solid solution formed.and its phase diagram is composed of two invariant points,five univariate curves and four crystal phase regions.The four crystallization fields correspond to the single salt KCl,SrCl₂·6H₂O,CaCl₂·6H₂O and the solid solution Ca_x(Sr_1-x)Cl₂·6H₂O.