scholarly journals THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 1 MOLARAND 3 MOLAR NITRIC ACID

2007 ◽  
Author(s):  
F Fondeur ◽  
D David Hobbs ◽  
S Samuel Fink
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Extraction Solvent ◽  
Spectroscopic Analyses

scholarly journals Thermal and Spectroscopic Analyses of Caustic Side Solvent Extraction Solvent Contacted with 16 Molar and 8 Molar Nitric Acid

2008 ◽  
Vol 43 (9-10) ◽  
pp. 2826-2839 ◽  
Author(s):  
F. F. Fondeur ◽  
D. T. Hobbs ◽  
S. D. Fink
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Extraction Solvent ◽  
Spectroscopic Analyses

scholarly journals Neptunium extraction by N,N-dialkylamides

2020 ◽  
Vol 108 (9) ◽  
pp. 707-716
Author(s):  
Jarrod M. Gogolski ◽  
Peter R. Zalupski ◽  
Travis S. Grimes ◽  
Mark P. Jensen
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Radioactive Waste ◽  
Partial Oxidation ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Organic Solutions

AbstractSeparation of neptunium by solvent extraction has been based on tributylphosphate (TBP) for decades, but TBP is not fully incinerable, which adds to the burden of long-lived radioactive waste. Alternatives to TBP for uranium and plutonium extraction, such as the N,N-diakylamides, previously have been explored in the hopes of transitioning to an extractant that is incinerable. Four N,N-diakylamides, N,N-dihexylhexanamide (DHHA), N,N-dihexyloctanamide (DHOA), N,N-di(2-ethylhexyl)butanamide (DEHBA), and N,N-di(2-ethylhexyl)-iso-butanamide (DEHiBA) were considered in this work for their potential to extract millimolar concentrations of Np(IV), Np(V), and Np(VI) from nitric acid solutions into organic solutions containing 1 M extractant in Exxsol D60. Under these conditions the branching of the alkyl substituents affects the extractability of Np(VI) and Np(IV), causing three of the dialkylamides, DHHA, DHOA and DEHBA, to extract neptunium in the expected order Np(VI) > Np(IV) > > Np(V). In contrast, branched DEHiBA is so poor an extractant for Np(IV) that the extraction order becomes Np(VI) > > Np(V) > Np(IV) between 0.1 and 5.6 M HNO3 due to partial oxidation of the Np(V) in nitric acid.

Extraction of tetra- and hexavalent actinide ions from nitric acid solutions using some diglycolamide functionalized calix[4]arenes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rajesh B. Gujar ◽  
Parveen K. Verma ◽  
Prasanta K. Mohapatra ◽  
Mudassir Iqbal ◽  
Jurriaan Huskens ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Extraction Efficiency ◽  
Minor Actinide ◽  
Acid Solutions ◽  
Extraction Mechanism ◽  
Nitrate Ion ◽  
Nitric Acid Solutions ◽  
Actinide Ions ◽  
Acid Extractant

Abstract Neptunium is one of the most important minor actinide elements with some of its isotopes having very long half-lives, therefore necessitating its separation from acidic radioactive wastes. Solvent extraction of Np4+ and NpO2 2+ was studied using three multiple diglycolamide (DGA) extractants with n-propyl, n-octyl and 3-pentyl substituents termed as L I , L II and L III , respectively, in a mixed diluent of 5% isodecanol and 95% n-dodecane. For comparison purpose, the extraction of Pu4+ and UO2 2+ was carried out under identical conditions. The extraction efficiency of the ligands for the tetravalent ions followed the trend: L II  > L I  > L III , which changed to L III  > L II  > L I for the hexavalent ions. While the extraction of the tetravalent ions was reasonably good (ca. 90–98%) with an extremely low (5.0 × 10−5 M) ligand concentration, poor extraction (ca. 5–16%) of the hexavalent ions was seen even with a 20 times higher concentration of the ligand. In general, Pu4+ was better extracted than Np4+, while NpO2 2+ was marginally better extracted then UO2 2+. A ‘solvation’ type extraction mechanism was proposed based on the extraction profiles obtained as a function of the concentrations of the feed nitric acid, extractant as well as nitrate ion. The extracted species were found out to be M(NO3)4·mL and MO2(NO3)2·nL (M = Np or Pu, 1 < m < 2, n ≃ 1).

Syntheses and evaluation of new hydrophilic azacryptands used as masking agents of technetium in solvent extraction processes

2021 ◽  
Vol 50 (5) ◽  
pp. 1620-1630
Author(s):  
Alexiane Thevenet ◽  
Ana Miljkovic ◽  
Sonia La Cognata ◽  
Cécile Marie ◽  
Christelle Tamain ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Acid Medium ◽  
Separation Process ◽  
Nitric Acid Medium ◽  
Masking Agents ◽  
Extraction Processes

New azacryptands with the addition of hydrophilic groups were synthesized to bind selectively the pertechnetate anion in nitric acid medium, and avoid its extraction in the separation process.

Separation of selenium (IV) and tellurium (IV) from nitric acid medium by solvent extraction using CYANEX 301

2021 ◽  
Author(s):  
F. Mahmoudiani ◽  
S. A. Milani ◽  
F. Hormozi ◽  
A. Yadollahi
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Acid Medium ◽  
Nitric Acid Medium ◽  
Cyanex 301

scholarly journals Separation of Ag(I) by Ion Exchange and Cementation from a Raffinate Containing Ag(I), Ni(II) and Zn(II) and Traces of Cu(II) and Sn(II)

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 112 ◽  
Author(s):  
Wei Xing ◽  
Man Lee ◽  
Seung Choi
Keyword(s):  
Ascorbic Acid ◽  
Nitric Acid ◽  
Solvent Extraction ◽  
Ion Exchange ◽  
Anode Slime ◽  
Silver Particles ◽  
Copper Sheet ◽  
Agno3 Solution ◽  
Micron Size ◽  
Leaching Solution

Ion exchange and cementation experiments were done to separate silver(I) from a raffinate containing silver(I), nickel(II), and zinc(II) and small amounts of copper(II) and tin(II). The raffinate resulted from the recovery of gold(III), tin(II) and copper(II) by solvent extraction from a leaching solution of anode slime. Ion exchange with anionic resins was not effective in separating silver(I) because tin(II) and zinc(II) were selectively adsorbed into the anionic resins. It was possible to separate silver(I) by cementation with copper sheet. Treatment of the cemented silver with nitric acid solution increased the purity of silver(I) in the solution from 50.9% to 99.99%. Adjusting the pH of the AgNO3 solution to higher than 6, followed by adding ascorbic acid as a reducing agent, led to the synthesis of silver particles with micron size.

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