Usma CL, Dourdain S, Arrachart G, Pellet-Rostaing S. Solvent extraction of rare earths elements from nitrate media in DMDOHEMA/ionic liquid systems: performance and mechanism studies.
RSC Adv 2021;
11:31197-31207. [PMID:
35496839 PMCID:
PMC9041442 DOI:
10.1039/d1ra05359k]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 09/12/2021] [Indexed: 01/18/2023] Open
Abstract
Extraction of La(iii), Eu(iii) and Fe(iii) was compared in n-dodecane and two ionic liquids (ILs) (1-ethyl-1-butylpiperidinium bis (trifluoromethylsulfonyl)imide [EBPip+] [NTf2−] and 1-ethyl-1-octylpiperidinium bis (trifluoromethylsulfonyl)imide [EOPip+] [NTf2−]). Using the extractant N,N′-dimethyl-N,N′-dioctylhexylethoxymalonamide (DMDOHEMA), the effect of pH was investigated in detail to recover extraction mechanisms. The use of ILs as the organic solvent instead of n-dodecane, greatly enhances extraction efficiency, and an ionic liquid with a shorter alkyl chain [EBPip+] [NTf2−] provides higher extraction than [EOPip+] [NTf2−]. The mechanistic study points out that for low nitric acid concentrations ([HNO3] ≤ 0.01 M), metal is extracted via a cation of the ionic liquids, while for higher nitric acid concentrations ([HNO3] ≥ 1.0 M), extraction occurs through pure solvation mechanism of DMDOHEMA as in conventional diluents. This latter case is of high interest for applications, as higher extraction can be obtained without any loss of ILs by ion exchange mechanisms.
Extraction of La(iii), Eu(iii) and Fe(iii) was compared in n-dodecane and in two ionic liquids (ILs) [EBPip+] [NTf2−] and [EOPip+] [NTf2−]. Extraction mechanisms have been investigated as a function of pH.![]()
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