Solvent extraction of rare earths elements from nitrate media in DMDOHEMA/ionic liquid systems: performance and mechanism studies

Abstract

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.

Long-Range Organization Study of Piperidinium-Based Ionic Liquids by Polarizable Molecular Dynamics Simulations

“…This class of ILs is, however, very promising not only for various electrochemical applications 49 such as high-voltage supercapacitors, 50 electrolytes in lithium−metal batteries at room temperature, 50,51 and high capacity anodes for lithium-ion batteries 15 but also for applications in liquid−liquid extraction. 19,20 Most of molecular dynamics (MD) studies focusing on the nanoscale organization of ILs use the nonpolarizable force field developed by Canongia Lopes and Padua. 52−54 This force field allowed great advances in the understanding of the ILs structure.…”

“…They have many properties of interest such as good thermal and electrochemical stability and very low volatility. − The air stability of ILs makes them theoretically recyclable and therefore more advantageous from economic and environmental points of view. Associated with their performance versatility under slight modifications of the chemical architecture, these properties make them tunable and interesting for many applications in electrochemistry, catalysis, or extraction. − …”

“…To our best knowledge, only one study has been conducted to understand the long-range organization of piperidinium-based ILs and none via simulations. This class of ILs is, however, very promising not only for various electrochemical applications such as high-voltage supercapacitors, electrolytes in lithium–metal batteries at room temperature, , and high capacity anodes for lithium-ion batteries but also for applications in liquid–liquid extraction. , …”

Exploring the Aggregation Behavior of Extractant Molecules in Ionic Liquids: A Coupled Polarizable Molecular Dynamics and SAXS Study

“…In this study, we investigated the aggregation behavior of the N , N ′-dimethyl, N , N ′-dioctylhexylethoxymalonamide (DMDOHEMA) molecules, a malonamide commonly employed in industrial processes for the extraction of lanthanide and actinide cations, − in three different solvents: two piperidinium- and (trifluoromethylsulfonyl)­imide-based ILs (1-ethyl-1-butylpiperidinium bis­(trifluoromethylsulfonyl)­imide ([EBPip + ]­[NTf 2 – ]) and 1-ethyl-1-octylpiperidinium bis­(trifluoromethylsulfonyl)­imide ([EOPip + ]­[NTf 2 – ])) and n -dodecane that mimics a typical conventional aliphatic solvent. As reported by Usma et al, when compared to conventional aliphatic organic solvents, the selected ILs exhibit a higher extraction efficiency, and no cation exchange was detected in the aqueous phase to account for this high efficiency. Conventional techniques for fitting small-angle X-ray scattering (SAXS) data are not applicable for studying the aggregation behavior in ILs, mainly due to the presence of solvent peaks at relatively low q -values.…”

“…Therefore, there is a need to develop efficient and sustainable solvents for extracting and recycling these metals. While ionic liquids (ILs) are considered as greener alternatives to common solvents due to their low vapor pressure and nonflammability, − their use in extraction systems is not widespread because no prediction allows one to choose the right IL to obtain efficient extraction. Thus, understanding and predicting the extraction mechanisms of ILs are critical for their efficient use in solvent extraction.…”