Inorganic Chemicals Industry ›› 2023, Vol. 55 ›› Issue (2): 61-66.doi: 10.19964/j.issn.1006-4990.2022-0273

• Research & Development • Previous Articles     Next Articles

Study on phase equilibrium of quinary system of Li+,Na+,Mg2+//SO42-,Cl--H2O at 258.15 K

YAN Fangning(),GUO Jinchun,HUANG Xueli(),ZHOU Tingting,WANG Xueying,LUO Qinglong,ZOU Xuejing   

  1. College of Chemical Engineering,Xinjiang University,Key Laboratory of Cleaner Transition of Coal & Chemicals Engineering of Xinjiang Uyghur Autonomous Region,Urumqi 830017,China
  • Received:2022-05-07 Online:2023-02-10 Published:2023-02-16
  • Contact: HUANG Xueli E-mail:1324648810@qq.com;xuelih@163.com

Abstract:

Most lithium salt lakes in China are located in areas with drought,little rain,cold and long winters,such as Qinghai Tibet and Xinjiang.To guide the process of lithium extraction at low temperature,enrich the target ions by using cold energy in winter and clarify the salt precipitation law of lithium-containing salt lake at low temperature,the phase equilibrium of the interactive quinary system of Li+,Na+,Mg2+//SO42-,Cl--H2O under saturated NaCl·2H2O at 258.15 K was investigated by isothermal dissolution method and the phase diagram was constructed.There were four invariant points,six two-salt crystallization fields(NaCl·2H2O+Na2SO4·10H2O,NaCl·2H2O+MgCl2·8H2O,NaCl·2H2O+MgSO4·7H2O,NaCl·2H2O+Li2SO4·H2O,NaCl·2H2O+LiCl·2H2O, NaCl·2H2O+LiCl·MgCl2·7H2O)and nine univariate solubility curves in the phase diagram.LiCl·MgCl2·7H2O was the only double salt in the phase diagram,and its crystallization field was the smallest.The crystallization field of Na2SO4·10H2O was the largest in the phase diagram.Compared with the stable phase diagram of the quinary system at 273.15 K,the sulfate type double salt was disappeared,the double salt crystallization zone was reduced to 1,and the invariant point was reduced to 4,and the correlation system was simplified.Cooling the brine of Seniehu lake to 258.15 K could effectively separate sulfate and achieve the purpose of enriching lithium.

Key words: salt lake, lithium, low temperature, quinary system, phase equilibrium

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