Abstract

In this study, a hydroxyl-functionalized ionic liquid 1-hydroxyethyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide ([OHEMIM][NTf₂]) and tri-n-butyl phosphate (TBP) were used as co-extraction reagent and extractant, respectively, to improve the extraction efficiency of Li⁺ and the separation factor of Li–Mg from brine with a high Mg/Li ratio. The extraction efficiency of Li⁺ is 94.2% and the separation factor of Li–Mg is 539 under the optimal condition. The washing efficiency of Mg²⁺ and K⁺ is close to 100% using 0.6 mol L⁻¹ LiCl and 1.8 mol L⁻¹ NaCl as the washing solution at an organic-to-aqueous phase ratio (O/A) of 4, and the stripping efficiency of Li⁺ is about 98.0% using 1.0 mol L⁻¹ HCl as the stripping agent at an O/A phase ratio of 1. The extraction efficiency of Li⁺ is reduced by less than 4.4% after seven cycles, indicating that the extraction system is stable and reusable.

Graphical Abstract

中文翻译：

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羟基官能化离子液体和磷酸三正丁酯从卤水中回收高Mg / Li比率的锂

摘要

在这项研究中，羟基官能化的离子液体1-羟乙基-3-甲基咪唑鎓双（三氟甲基磺酰）亚胺（[OHEMIM] [NTF ₂ ]）和三- ñ丁基磷酸酯（TBP）作为共萃取试剂和萃取剂，分别提高Li ⁺的萃取效率和从高Mg / Li比的盐水中分离Li-Mg的分离系数。在最佳条件下，Li ⁺的萃取效率为94.2％，Li–Mg的分离系数为539。使用0.6 mol L ^-1 LiCl和1.8 mol L ^-1 NaCl作为洗涤液，Mg ²⁺和K ⁺的洗涤效率接近100％（Ó /阿的）4和Li的汽提效率⁺有关使用98.0％1.0摩尔L为^-1以HCl为汽提剂Ó /阿立的提取效率的相位1.比⁺是由小于减少七个循环后为4.4％，表明萃取系统稳定且可重复使用。

图形概要