N523-TBP混合萃取体系从盐湖卤水中萃取锂的机理研究

Mechanism Study of Extracting Lithium from Brine with N523-TBP Mixed Extraction System

中文关键词:  锂  N523  TBP  溶剂萃取  共萃取效应  盐析效应  共存离子

英文关键词:N523  TBP  Solvent Extraction  Co-extraction Effect  Salting-out Effect  Co-existing Ion  Lithium

中文摘要:

      研究了N523(N,N-二乙基己基乙酰胺)-TBP(磷酸三丁酯)混合萃取体系从盐湖卤水中萃取锂的共萃取效应、盐析效应及共存离子影响。FeCl₃、CoCl₂、NiCl₂、CuCl₂、ZnCl₂等过渡金属氯化物盐对锂的共萃取效应研究表明,FeCl₃是最佳的共萃剂,Fe/Li摩尔比为1.3时萃取效果最优。卤水中KCl、CaCl₂、NaCl、MgCl₂、AlCl₃的盐析效应研究表明,MgCl₂是萃取锂天然的最佳盐析剂。卤水中Na⁺、K⁺、Ca²⁺等共存离子对锂萃取效果的影响研究表明,锂与共存离子的分离因数顺序为βLiMg>βLiK>βLiNa>βLiCa。N523-TBP混合萃取体系特别适合从高镁卤水中萃取锂,但不适于从含钙较高的卤水中萃取锂。

英文摘要:

      :The co-extraction effect, salting-out effect and effect of coexistence ions on lithium extraction by N523-TBP mixed extraction system were studied in this paper.The effects of lithium extraction of different co-extraction agent (FeCl₃, CoCl₂, NiCl₂, CuCl₂ and ZnCl₂) and different Fe/Li molar ratio were studied respectively.The results showed that the optimum co-extraction agent was FeCl₃, and the optimum Fe/Li molar ratio was 1.3.The study of the salting-out effect of KCl, CaCl₂, NaCl, MgCl₂ and AlCl₃ on lithium extraction showed that MgCl₂ was the best natural salting-out agent. The effect of coexisting ions (Na⁺, K⁺, Ca²⁺) on lithium extraction showed that the sequence of separation factor between lithium and coexisting ions was βLiMg>βLiK>βLiNa>βLiCa.The mixed extraction system is especially suitable for extracting lithium from brine with high concentration of magnesium,but cannot be applied to brine containing calcium.