scholarly journals SEPARATION OF PROTACTINIUM FROM THORIUM IN NITRIC ACID SOLUTIONS BY SOLVENT EXTRACTION WITH TRIBUTYL PHOSPHATE OR BY ADSORPTION ON PULVERIZED UNFIRED VYCOR GLASS OR SILICA GEL

1963 ◽  
Author(s):  
J. G. Moore ◽  
R. H. Rainey
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Silica Gel ◽  
Tributyl Phosphate ◽  
Acid Solutions ◽  
Vycor Glass ◽  
Nitric Acid Solutions

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).

Extraction of tetravalent berkelium by tributyl phosphate from nitric acid solutions

1982 ◽  
Vol 75 (1-2) ◽  
pp. 113-120 ◽  
Author(s):  
N. G. Yakovlev ◽  
V. N. Kosyakov ◽  
G. M. Kazakova
Keyword(s):  
Nitric Acid ◽  
Tributyl Phosphate ◽  
Acid Solutions ◽  
Nitric Acid Solutions

Solvent extraction of silver from nitric acid solutions by calix[4]arene amide derivatives

2008 ◽  
Vol 61 (3) ◽  
pp. 366-374 ◽  
Author(s):  
V. Stankovic ◽  
L. Outarra ◽  
F. Zonnevijlle ◽  
Ch. Comninellis
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Amide Derivatives

Solvent extraction of thorium(IV) ion with N,N,N,N-tetrabutylsuccinylamide from nitric acid solutions

1996 ◽  
Vol 213 (3) ◽  
pp. 199-205 ◽  
Author(s):  
You-Shao Wang ◽  
Chao-Hong Shen ◽  
Yong-hui Yang ◽  
Jian-Kang Zhu ◽  
Bo-Rong Bao
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Acid Solutions ◽  
Nitric Acid Solutions
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