Extraction Of Lithium from Salt Lake Brine with a High Mg/Li Ratio Using Nantf2·Tbp

Abstract

NTf2--based ionic liquids (ILs)/tri-n-butyl phosphate (TBP) systems can be used for extraction of Li+, but ILs are very expensive and their cations can cause the contamination of the aqueous phase in the extraction process. In this study, an inexpensive raw material lithium bis(trifluoromethanesulphonyl)imide (LiNTf2) for preparing NTf2--based ILs is used to prepare extraction organic phase NaNTf2·TBP. The preparation conditions of extraction organic phase NaNTf2·TBP was investigated. Under the optimal extraction condition, the single extraction efficiency of Li+ is 91.7%. The extraction system is stable after seven extraction cycles.

Keywords: Lithium extraction, high Mg/Li ratio, magnesium/lithium separation, lithium bis(trifluoromethanesulphonyl)imide