Amine/Carboxylic Acid Based Bifunctional Ionic Liquids as Extractants for Nd(III), Sm(III) and Eu(III) from Aqueous Solution Containing EDTA

Abstract

Two bi-functional ionic liquid extractants (Bif-ILs) comprising tertiary amine and carboxylic acids, namely [TOAH] + [OHex] À (Tri-n-octylaminehexanoate) and [TOAH] + [ODec] À (Tri-n-octylaminedecanoate) in kerosene have been used for extraction of Nd(III), Sm(III) and Eu(III) from aqueous phase with EDTA as a complexing agent. The extraction ability of both the extracting agents has been analyzed with respect to variations in shaking time, concentration of extractant, aqueous phase pH, molarity of EDTA, diluents and phase volume ratio. Using 0.08 mol/L EDTA,extraction of Nd(III) was maximum with both the extractants followed by Sm(III) and Eu(III).At 4 : 1 (O/A) phase volume ratio, the extraction percentages using [TOAH] + [OHex] À were 93.42 % (Nd), 89.83 % (Sm), 84.14 % (Eu) and with [TOAH] + [ODec] À the values were 90.42 % (Nd), 89.37 % (Sm), 83.65 % (Eu), respectively.Extraction efficiency of both Bif-ILs is maximum for Nd(III). Stripping was quantitative with HNO 3 and HCl.Speciation studies and FTIR spectra provide valuable information regarding the stoichiometry of the extracted species.

Thermodynamic Data of Separating Yttrium from Heavy Rare Earths via a Phenoxypropionate-Based Ionic Liquid

“…For the aim of efficient separation of REEs, solvent extraction and adsorption have been broadly used in the past decades. ,− Neutral phosphorus, organic phosphonic acid, and carboxylic acid are widely used extractants, such as tri-butyl phosphate (TBP), di­(2-ethylhexyl) phosphoric acid (P204), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507), and naphthenic acid (NA). ,− However, these extraction systems also have some shortcomings that need to be improved and developed. TBP needs a higher salinity and peracid system, which means that larger number of chemical reagents are consumed.…”