Solvent extraction of lithium ions by tri-n-butyl phosphate using a room temperature ionic liquid
Solvent extraction of lithium ions by tri-n-butyl phosphate using a room temperature ionic liquid
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DOI：
10.1016/j.molliq.2016.01.025
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发表时间：
2016-03
影响因子：
6
通讯作者：
Chenglong Shi;Y. Jing;Yongzhong Jia
中科院分区：
文献类型：
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作者：
Chenglong Shi;Y. Jing;Yongzhong Jia
锂离子和镁离子之间的分离仍然具有挑战性。本文研究了以中性磷化合物磷酸三正丁酯(TBP)为萃取剂，将含镁盐湖卤水中的锂离子从离子液体1-丁基-3-甲基咪唑双(三氟甲基磺酰基)亚胺([C4mim][NTf2])中萃取。考察了盐湖卤水酸度、离子液体用量和相比对锂离子萃取行为的影响。在最佳条件下，锂的单次萃取率为92.37%，是一种回收锂离子的有效萃取体系。在热力学研究的基础上，得到了锂离子萃取反应的热力学参数。通过斜率分析确定了萃合物的存在形式，表明络合物中金属与配体的比例为1：1。还进行了紫外-可见光谱和傅里叶变换红外光谱(FTIR)研究，以了解提取物种的性质。
Separation among lithium ion and magnesium ion remains challenging. In this work, solvent extraction of lithium ions from the Mg(II)-containing salt lake brine into a commonly used ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([C4mim][NTf2]) using the neutral phosphorus compound tri-n-butyl phosphate (TBP) as the extractant was investigated. The extraction behavior of lithium ions was investigated as a function of various parameters: acidity of the salt lake brine, dosage of ionic liquid and phase ratio. Under the optimal conditions, the single extraction efficiency of lithium was 92.37%, which indicated that it was an efficient extraction system for the recovery of lithium ions. Based on the study of thermodynamics, thermodynamic parameters of the lithium ion extraction reaction were obtained. The extracted species were ascertained from slope analysis method which indicated 1:1 (metal:ligand) ratio in the complex. UV–visible and Fourier transform infrared spectroscopy (FTIR) studies were also carried out to understand the nature of the extracted species.