Ion-pair induced solvent extraction of lithium(Ⅰ) from acidic chloride solutions with tributyl phosphate

作者：Li Cui; Lijuan Wang; Ming Feng; Li Fang; Yanxia Guo; Fangqin Cheng^*

来源：Green Energy & Environment, 2021, 6(04): 607-616.

Lithium (Li) is an important energy metal in the 21st century.However,the selective recovery of Li is still a big challenge,especially from acidic solutions with multiple metal ions existence.Herein we report a new ion pair induced mechanism for selectively extracting Li+from acidic chloride solutions by tributyl phosphate (TBP).It is shown that the acidity and the chloride ions in the aqueous phase have great effects on the extraction of Li+.The FT-IR,UV-Vis and ESI-MS experiments provide solid evidence for the formation of ion-pair complex[Li(TBP)n(H2O)m]+[FeCl4]-(n?1,2,3;m?0,1) in the organic phase,which brings about the effective and efficient extraction of Li+.This mechanism can overcome the Hofmeister bias and allow for the selective extraction of Li+from the extremely hydrophilic chlorides.It has also been proved that the loaded Li in TBP can be effectively stripped by concentrated HCl solution with a Li/Fe separation factor>500.The understanding of the ion-pair transport mechanism is helpful for optimizing the recovery process or further advancing more efficient recovery techniques for Li from acidic liquor.

• 出版日期2021
• 单位山西大学