Phase Equilibria in the Quaternary Systems (KCl + CaCl₂ + SrCl₂ + H₂O) and (LiCl + NaCl + SrCl₂ + H₂O) at 288.15 K and 0.1 MPa

Abstract

Phase equilibria of the quaternary systems (KCl + CaCl 2 + SrCl 2 + H 2 O) and (LiCl + NaCl + SrCl 2 + H 2 O) at 288.15 K and 0.1 MPa were studied using the isothermal dissolution method, and the phase diagrams of the two systems mentioned above were plotted. There are two invariant points and four crystallization regions in the quaternary system (KCl + CaCl 2 + SrCl 2 + H 2 O). Besides the crystallization regions of the minerals KCl, CaCl 2 •6H 2 O, and SrCl 2 •6H 2 O, the solid solution (Ca,Sr)Cl 2 •6H 2 O was found. The strontium and calcium salts can be separated from each other by avoiding crystallization in the solid solution region. There are two invariant points and four crystallization regions corresponding to NaCl, SrCl 2 • 6H 2 O, SrCl 2 •2H 2 O, and LiCl•2H 2 O in the quaternary system (LiCl + NaCl + SrCl 2 + H 2 O). Lithium chloride has a strong salting-out effect on NaCl and SrCl 2 •6H 2 O. The experiment results of the quaternary systems (KCl + CaCl 2 + SrCl 2 + H 2 O) and (LiCl + NaCl + SrCl 2 + H 2 O) have a significant value for separating and purifying minerals from the oilfield brine in the Nanyishan Section of the Qaidam Basin.

Experimental and Thermodynamic Modeling Study of the Solid–Liquid Equilibria in the Quaternary System (LiCl + MgCl2 + Li2SO4 + MgSO4 + H2O) at 288.15 K and 0.1 MPa

“…The method of isothermal dissolution was adopted in this work. , Briefly, a series of synthesized complexes were put into polyethylene bottles and a certain amount of deionized distilled water was added, then the bottles were sealed and placed in a thermostatic bath with magnetic stirring at (288.15 ± 0.1) K. A stirring speed of 150 rev/min was used to accelerate the equilibrium of the solution. The supernatant was extracted quickly using a syringe connected to a 4# glass filter tube for composition analysis at intervals.…”

Phase Equilibria in the Quaternary System LiCl–NaCl–SrCl2–H2O at 273 and 323 K

“…Some phase equilibria containing lithium chloride or strontium chloride have been reported, such as the following systems, the ternary system LiCl–NaCl–H 2 O at 273, 288, 308, 323, 333, and 348 K, − LiCl–KCl–H 2 O at 273, 288, 308, 323, and 333 K, , LiCl–SrCl 2 –H 2 O at 273, 308, and 323 K, − NaCl–KCl–H 2 O at 293–360 K, and NaCl–SrCl 2 –H 2 O at 273, 288, 323, 333, and 373 K, − as well as the quaternary systems NaCl–KCl–SrCl 2 –H 2 O at 323, 348, and 373 K, − and LiCl–NaCl–SrCl 2 –H 2 O at 308, 288, and 298 K, ,, and the multicomponent system LiCl–NaCl–KCl–SrCl 2 –H 2 O at 298 K . Our research group has been committed to the study of the phase equilibria of the water–salt system.…”

“…Secondly, the study of multi-temperature phase balance can find and excavate some or all of the mother liquor in the chemical production process to recycle rationally, improve the recovery rate of active ingredients in the mother liquor, and achieve the purpose of saving resources, energy saving, and emission reduction. For experimental and theoretical research of water–salt systems including lithium chloride, sodium chloride, and strontium chloride, only the quaternary system LiCl–NaCl–SrCl 2 –H 2 O at 308, 288 and 298 K was studied. ,, In this work, the solubility data were obtained, water-content diagrams were drawn, and the X-ray powder diffraction (XRD) patterns were gained at some invariant points of the quaternary system LiCl–NaCl–SrCl 2 –H 2 O at 273 and 323 K.…”

“…"salt lakes lithium" reserves in China include about 19.82 million tons of lithium chloride in Qinghai salt lakes, and salt lakes in Tibet have identified more than 17.4 million tons. 7,8 Some phase equilibria containing lithium chloride or strontium chloride have been reported, such as the following systems, the ternary system LiCl−NaCl−H 2 O at 273, 288, 308, 323, 333, and 348 K, 9−12 LiCl−KCl−H 2 O at 273, 288, 308, 323, and 333 K, 12,13 LiCl−SrCl 2 −H 2 O at 273, 308, and 323 K, 14−16 NaCl−KCl−H 2 O at 293−360 K, 17 and NaCl−SrCl 2 −H 2 O at 273, 288, 323, 333, and 373 K, 18−21 as well as the quaternary systems NaCl−KCl−SrCl 2 −H 2 O at 323, 348, and 373 K, 21−23 and LiCl−NaCl−SrCl 2 −H 2 O at 308, 288, and 298 K, 18,24,25 and the multicomponent system LiCl−NaCl−KCl−SrCl 2 −H 2 O at 298 K. 26 Our research group has been committed to the study of the phase equilibria of the water−salt system. Some of the ternary, quaternary, and quinary subsystems of the water−salt system Li + , Na + , K + //CO 3 2− , SO The study of multi-temperature phase equilibria can provide theoretical support for comprehensive and efficient utilization of salt lake brine resources.…”

“…For experimental and theoretical research of water−salt systems including lithium chloride, sodium chloride, and strontium chloride, only the quaternary system LiCl−NaCl−SrCl 2 −H 2 O at 308, 288 and 298 K was studied. 18,24,25 In this work, the solubility data were obtained, water-content diagrams were drawn, and the X-ray powder diffraction (XRD) patterns were gained at some invariant points of the quaternary system LiCl− NaCl−SrCl 2 −H 2 O at 273 and 323 K.…”