Cumulative study on solvent extraction of elements by N,N,N′,N′-tetraoctyl-3-oxapentanediamide (TODGA) from nitric acid into n-dodecane

Zhixuan, Zhu; Sasaki, Yoshiyuki; Suzuki, H.; Suzuki, Shinichi; Kimura, Takaumi

doi:10.1016/j.aca.2004.09.023

Cited by 277 publications

(158 citation statements)

References 16 publications

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“…The greatest advantage of TODGA in hydrometallurgical recycling of the NdFeB magnets is the very limited extraction of Fe by TODGA ligands, the element making the majority of the material, from nitric acid solutions. In a study by Zhu et al [9], it was shown that divalent ions with ionic radii smaller than 80 pm and trivalent ions with ionic radii smaller than 70 pm show very weak extraction with TODGA in n-dodecane, which is in accordance with this study. The ionic radius thus plays a role in solvent extraction with TODGA, with REEs having larger ionic radii being prioritized in the extraction process.…”

Section: Effects Of Todga Concentration and Diluents On Solvent Extrasupporting

confidence: 92%

“…A promising extractant that complies with the CHNO principle and could be used for the extraction of REEs out of the leachate formed from NdFeB magnet waste is TODGA (N, N, N 0 , N 0 -tetraoctyl-diglycolamide). This molecule has previously shown good extraction properties of lanthanides and actinides when extracted from highly acidic solutions [8,9]. It has also been found that the loading capacity of 0.1 M TODGA-n-dodecane is 0.008 M Nd(III) with an aqueous phase of 3 M HNO3 [8].…”

Section: Introductionmentioning

confidence: 83%

“…It has also been found that the loading capacity of 0.1 M TODGA-n-dodecane is 0.008 M Nd(III) with an aqueous phase of 3 M HNO3 [8]. An especially interesting fact for this research is the very low distribution ratios (\10 -2 ) of Fe(III) and Al(III) which were observed during extractions with 0.1 TODGA in n-dodecane from 2.9 M nitric acid, since aluminum and iron are expected to be present in the leachate produced [9]. In 2015 at the Oak Ridge National Laboratory, Tennessee, a process with membrane solvent extraction was conducted comparing the extraction of REEs from a neodymium magnet leachate with Cyanex 923 and TODGA.…”

Section: Introductionmentioning

confidence: 91%

“…The organic-to-aqueous phase ratio was H = 1. The vials were shaken for 50 min, which was enough to achieve equilibrium [9] at a temperature of 25 ± 1°C using a shaking machine (IKA Vibrax VXR Basic) with an adjacent thermostatic bath. The shaking speed was 1750 vibrations per minute.…”

Section: Model Solution Testingmentioning

confidence: 99%

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Characterization and Leaching of Neodymium Magnet Waste and Solvent Extraction of the Rare-Earth Elements Using TODGA

Gergorić

Ekberg

Foreman

et al. 2017

J. Sustain. Metall.

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The rare-earth elements (REEs) are considered as some of the most critical elements in the EU and the USA today. E-scrap, such as end-of-life neodymium magnets, could be a viable secondary source for the recovery of these elements. Neodymium magnets (NdFeB) consist of considerable amounts of Nd, Dy, Pr, and some other REEs, depending on the specific application. Apart from REEs, neodymium magnets are made up of around 60% iron, which can pose a challenge in their recycling. For example, iron can be dissolved along with other elements during leaching or co-extracted during solvent extraction. In this work, extraction of REEs with TODGA (tetraoctyl-diglycolamide) from a real leachate, obtained by neodymium magnet powder dissolution in nitric acid, was studied. The goal was to selectively extract the REEs from other elements in the solution. TODGA was used as the extracting agent due to its selective extraction properties for REEs and other f-block elements. The influence of the diluent on the overall extraction and the selectivity of the extraction was studied in order to determine application feasibility of future processes. To this end, experiments using Solvent 70 (hydrocarbons C11-C14, B0.5 wt% aromatics), hexane, toluene, cyclohexanone and 1-octanol as the diluents were performed. TODGA has shown good selectivity between REEs and other elements in solution under almost all conditions, reaching the highest distribution ratios of REEs in the aliphatic diluents, while the distribution ratios of other non-REEs reach a mere value of 0.1. An exception was cyclohexanone, which has the ability to extract small amounts of ions itself. The highest separation factors between Dy and the light REEs (Nd and Pr) were observed with a 0.01 M solution of TODGA in Solvent 70. REEs, as group, were extracted with 0.1 M solutions of TODGA in all diluents except for cyclohexanone, which led to extraction of Al and B at amounts greater than 10%. Stripping with over 98% efficiency was achieved using MQ water in one step.

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Section: Effects Of Todga Concentration and Diluents On Solvent Extrasupporting

confidence: 92%

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 91%

Section: Model Solution Testingmentioning

confidence: 99%

See 2 more Smart Citations

Characterization and Leaching of Neodymium Magnet Waste and Solvent Extraction of the Rare-Earth Elements Using TODGA

Gergorić

Ekberg

Foreman

et al. 2017

J. Sustain. Metall.

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show abstract

“…From a detailed investigation, TODGA shows high D values of di-, tri-, tetravalent metal ions. 6 Because of the variety of metal concentrations in SF and HLW, it is important to know the extraction capacity of metals with the different oxidation states using TODGA. For neodymium, an example of trivalent lanthanides and actinides, it was already reported that the stoichiometric extraction of Nd(III) to DGA concentration can be attained by mixing with the modifier of monoamide and using DGA with a long alkyl chain, i.e., N,N,N',N'-tetradodecyl-diglycolamide (TDdDGA).…”

Section: Introductionmentioning

confidence: 99%

Extraction Capacity of Diglycolamide Derivatives for Ca(II), Nd(III) and Zr(IV) from Nitric Acid to n-Dodecane Containing a Solvent Modifier

Sasaki¹,

Zhixuan²,

Sugo³

et al. 2005

ANAL. SCI.

Self Cite

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In order to evaluate the extraction property of new extractants, diglycolamide (DGA) compounds, we investigated the maximum extraction of di-, tri-, and tetravalent metal ions using nitric acid and n-dodecane. The limits of metal concentration (LOC) for Ca(II), Nd(III) and Zr(IV) in the organic phase are strongly influenced by HNO3 and the extractant concentration. For the purpose of enhancing the LOC value, we employed a modifier of the solvent, N,Ndihexyl-octanamide (DHOA) and DGA with a long alkyl chain, and examined the results. It was evident that LOC increased with the DHOA concentration and the length of the alkyl chain attached to the N atom of DGA. The stoichiometric values of LOC(Zr) estimated from the extraction reaction were confirmed by using the extraction condition: tetraoctyl-DGA/1 M DHOA + n-dodecane and 3 M HNO3.

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Highly Efficient Diglycolamide‐Based Task‐Specific Ionic Liquids: Synthesis, Unusual Extraction Behaviour, Irradiation, and Fluorescence Studies

Mohapatra

Sengupta

Iqbal

et al. 2013

Chemistry A European J

123

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Two new diglycolamide-based task-specific ionic liquids (DGA-TSILs) were evaluated for the extraction of actinides and lanthanides from acidic feed solutions. These DGA-TSILs were capable of exceptionally high extraction of trivalent actinide ions, such as Am(3+), and even higher extraction of the lanthanide ion, Eu(3+) (about 5-10 fold). Dilution of the DGA-TSILs in an ionic liquid, C(4)mim(+)·NTf(2)(-), afforded reasonably high extraction ability, faster mass transfer, and more efficient stripping of the metal ion. The nature of the extracted species was studied by slope analysis, which showed that the extracted species contained one NO(3)(-) anion, along with the participation of two DGA-TSIL molecules. Time-resolved laser fluorescence spectroscopy (TRLFS) analysis showed a strong complexation with no inner-sphere water molecule in the Eu(III)-DGA-TSIL complexes in the presence and absence of C(4)mim(+)·NTf(2)(-) as the diluent. The very high radiolytic stability of DGA-TSIL 6 makes it one of the most-efficient solvent systems for the extraction of actinides under acidic feed conditions.

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Cumulative study on solvent extraction of elements by N,N,N′,N′-tetraoctyl-3-oxapentanediamide (TODGA) from nitric acid into n-dodecane

Cited by 277 publications

References 16 publications

Characterization and Leaching of Neodymium Magnet Waste and Solvent Extraction of the Rare-Earth Elements Using TODGA

Characterization and Leaching of Neodymium Magnet Waste and Solvent Extraction of the Rare-Earth Elements Using TODGA

Extraction Capacity of Diglycolamide Derivatives for Ca(II), Nd(III) and Zr(IV) from Nitric Acid to n-Dodecane Containing a Solvent Modifier

Highly Efficient Diglycolamide‐Based Task‐Specific Ionic Liquids: Synthesis, Unusual Extraction Behaviour, Irradiation, and Fluorescence Studies

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