Effect of the nature of organophosphorous acid moiety on co-extraction of U(VI) and mineral acid from aqueous solutions using D2EHPA, PC88A and Cyanex 272

Das, Diptendu; Juvekar, Vinay A.; Rupawate, V. H.; Ramprasad, K.; Bhattacharya, R.

doi:10.1016/j.hydromet.2014.12.018

Cited by 22 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of m (HNO 3 ) aq,eq = 1 mol kg –1 and m (Eu 3+ ) aq,eq = 0.032 mol kg –1 , we can see that monomeric HDEHP is globally small. This is a consequence of the strong tendency of HDEHP (and most acidic extractants) toward dimerization and aggregation. , To create monomers, there is a penalty in energy for exposing the polar head groups toward the oil medium. Note that before the experimentally observed CAC, which is reported to be 0.21 mol dm –3 , the concentration of the aggregated HDEHP is moderate.…”

Section: Resultsmentioning

confidence: 99%

Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant

et al. 2019

View full text Add to dashboard Cite

We propose the statistical thermodynamic model for the prediction of the liquid–liquid extraction efficiency in the case of rare-earth metal cations using the common bis(2-ethyl-hexyl)phosphoric acid (HDEHP) extractant. In this soft matter-based approach, the solutes are modeled as colloids. The leading terms in free-energy representation account for: the complexation, the formation of a highly curved extractant film, lateral interactions between the different extractant head groups in the film, configurational entropy of ions and water molecules, the dimerization, and the acidity of the HDEHP extractant. We provided a full framework for the multicomponent study of extraction systems. By taking into account these different contributions, we are able to establish the relation between the extraction and general complexation at any pH in the system. This further allowed us to rationalize the well-defined optimum in the extraction engineering design. Calculations show that there are multiple extraction regimes even in the case of lanthanide/acid system only. Each of these regimes is controlled by the formation of different species in the solvent phase, ranging from multiple metal cation-filled aggregates (at the low acid concentrations in the aqueous phase), to the pure acid-filled aggregates (at the high acid concentrations in the aqueous phase). These results are contrary to a long-standing opinion that liquid–liquid extraction can be modeled with only a few species. Therefore, a traditional multiple equilibria approach is abandoned in favor of polydisperse spherical aggregate formations, which are in dynamic equilibrium.

show abstract

Section: Resultsmentioning

confidence: 99%

Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant

et al. 2019

View full text Add to dashboard Cite

show abstract

“…A process flow sheet has been proposed with 0.2M TEHP in n-paraffin as solvent for the recovery of U(VI) from simulated monazite nitrate leach solution. Among several methods for uranium separation is solvent extraction [10][11][12][13][14][15][16][17][18][19][20] and ionic exchanger resins [20,21] being considered as the simplest, applicable and the cheapest one depending on uranium ores grade. Several solvents were used for either yellow cake purification or uranium extraction such tri-butylphosphate, tri-capryl-methylammonium chloride, di-nonyl phenyl phosphoric acid, Cyanex 272 and tri-ethyl-hexyl-phosphate, [9,10,[12][13][14][15] which varied in its selectivity and costs, among all of these solvents; organophosphorus solvents came being exceedingly used in respect of its low price in comparable to other solvent and more being selective.…”

Section: Introductionmentioning

confidence: 99%

“…Among several methods for uranium separation is solvent extraction [10][11][12][13][14][15][16][17][18][19][20] and ionic exchanger resins [20,21] being considered as the simplest, applicable and the cheapest one depending on uranium ores grade. Several solvents were used for either yellow cake purification or uranium extraction such tri-butylphosphate, tri-capryl-methylammonium chloride, di-nonyl phenyl phosphoric acid, Cyanex 272 and tri-ethyl-hexyl-phosphate, [9,10,[12][13][14][15] which varied in its selectivity and costs, among all of these solvents; organophosphorus solvents came being exceedingly used in respect of its low price in comparable to other solvent and more being selective. TEHP [9,15] in regarding with other organophosphrous solvent shows very high selectivity and potentiality to be used in uranium extraction in only one publication and as an ionophore in potentiometric sensor for uranium determination with high accuracy and wide detection limit and life span for uranium potentiometric sensor [9], so it was recommended and demand as simple low price solvent for production of highly purified yellow cake prior to enrichment processing uranium without any more upgrading processes.…”

Section: Introductionmentioning

confidence: 99%

Upgrading of the Crude Yellow Cake to a Highly Purified Form using Tris(2-ethylhexyl) Phosphate in Presence of EDTA or CDTA

2017

View full text Add to dashboard Cite

A B S T R A C TUpgrading crude yellow cake was done by 0.05 M Tris 2-ethylhexyl Phosphate / kerosene from 5 M nitrate solution. More than 98 % of uranium extracted after 5 stages of contact, shaking time 5 minutes and volume phase ratio 1/1. Uranium stripping efficiency reached 99 % using distilled H2O, 10 minutes shaking time, (O/A) ratio 4/1 and three stripping stages. The purity of the produced cakes was enhanced by addition of EDTA or CDTA. The produced cake using TEHP followed by EDTA addition to the stripping solution before uranium precipitation step was the most preferable cake with lower gangues.

show abstract

“…Acidic organophosphorus extractants are widely used in the traditional hydrometallurgy field for extraction and separation of rare earth ions ), actinides 8 , etc. In recent years, they have also attracted more attention in the fields of secondary resource recycling and high-level liquid waste disposal 9 .…”

Section: Introductionmentioning

confidence: 99%

Synthesis of High Purity Nonsymmetric Dialkylphosphinic Acid Extractants

Wang

Xie

et al. 2017

JoVE

View full text Add to dashboard Cite

We present the synthesis of (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid as an example to demonstrate a method for the synthesis of high purity nonsymmetric dialkylphosphinic acid extractants. Low toxic sodium hypophosphite was chosen as the phosphorus source to react with olefin A (2,3-dimethyl-1-butene) to generate a monoalkylphosphinic acid intermediate. Amantadine was adopted to remove the dialkylphosphinic acid byproduct, as only the monoalkylphosphinic acid can react with amantadine to form an amantadine∙mono-alkylphosphinic acid salt, while the dialkylphosphinic acid cannot react with amantadine due to its large steric hindrance. The purified monoalkylphosphinic acid was then reacted with olefin B (diisobutylene) to yield nonsymmetric dialkylphosphinic acid (NSDAPA). The unreacted monoalkylphosphinic acid can be easily removed by a simple base-acid post-treatment and other organic impurities can be separated out through the precipitation of the cobalt salt. The structure of the (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid was confirmed by P NMR,H NMR, ESI-MS, and FT-IR. The purity was determined by a potentiometric titration method, and the results indicate that the purity can exceed 96%.

show abstract

Effect of the nature of organophosphorous acid moiety on co-extraction of U(VI) and mineral acid from aqueous solutions using D2EHPA, PC88A and Cyanex 272

Cited by 22 publications

References 19 publications

Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant

Colloidal Model for the Prediction of the Extraction of Rare Earths Assisted by the Acidic Extractant

Upgrading of the Crude Yellow Cake to a Highly Purified Form using Tris(2-ethylhexyl) Phosphate in Presence of EDTA or CDTA

Synthesis of High Purity Nonsymmetric Dialkylphosphinic Acid Extractants

Contact Info

Product

Resources

About