Extraction from nitric acid solutions

Butex A process for separating the radioactive components of spent nuclear fuel by solvent extraction from nitric acid solution, using diethylene glycol dibutyl ether (also called Butex, or dibutyl carbitol) as the solvent. Developed by the Ministry of Supply (later the UK Atomic Energy Authority) in the late 1940s. Operated at Windscale from 1952 until 1964 when it was superseded by the Purex process. 

Americium extraction from nitric acid solutions by 0.1 M chloroform solution of reagent I... 

Since 1958, more than 20 nuclides of actinides ranging from neptunium to einsteinium were identified and prepared for tracer studies. From neutron-irradiated uranium samples 2 9Np was adjusted to the pentavalent state and separated by TBP extraction from perchloric acid media. Plutonium-239 was separated by TBP extraction from nitric acid solution followed by anion exchange in a system of Dowex-1 resin and nitric acid. Neptunium-237 was separated from a spent fuel solution of JRR-1 (Japan Research Reactor -1) using anion exchange and TBP extraction. The TBP extraction in the hydrochloric acid medium is a simple and effective technique to purify neptunium from plutonium contamination. On the other hand, both anion exchange and solvent extraction with HDEHP could be used to separate tracer scale plutonium from irradiated neptunium targets. 

Although Celv (also Zr v, ThIV and Pulv) is readily extracted from nitric acid solutions by tributyl phosphate dissolved in kerosene or other inert solvent and can thus be readily separated from the + 3 lanthanide ions, the trivalent lanthanide nitrates can also be extracted under suitable conditions with various phosphate esters or acids. Extractability under given conditions increases with increasing atomic number it is higher in strong acid or high nitrate concentrations. 

Again methyltrioctylammonium based IL is proposed for La and Y + extraction from nitric acid solution (Belova et al., 2010). After analysis of extraction constants for various extraction reactions of [A336][Bis] (bis(2,4,4-trimethylpentyl)phosphinate) and lanthanides (Ln +), these authors have suggested that several species are formed in the organic phase according to eq. (15) (Table 5). The ratio between them depends on their stability and is difficult to evaluate. 

Tri-n-butyl phosphate, ( -C4H9)3P04. This solvent is useful for the extraction of metal thiocyanate complexes, of nitrates from nitric acid solution (e.g. cerium, thallium, and uranium), of chloride complexes, and of acetic acid from aqueous solution. In the analysis of steel, iron(III) may be removed as the soluble iron(III) thiocyanate . The solvent is non-volatile, non-flammable, and rapid in its action. 

The extractabilities of metal-organic complexes depend on whether inner or outer sphere complexes are formed. Case 1, section 4.2.1, the extraction of ura-nyl nitrate by TBP, is a good example. The free uranyl ion is surrounded by water of hydration, forming U02(H20)f, which from nitric acid solutions can be crystallized out as the salt U02(H20)6 (N03), though it commonly is written U02(N03)2(H20)6. Thus, in solution as well as in the solid salt, the UOf is surrounded by 6 HjO in an inner coordination sphere. In the solid nitrate salt, the distance du.o(nitrate) between the closest oxygen atoms of the nitrate anions, (0)2N0, and the U-atom is longer than the corresponding distance, du-o(water), to the water molecules, OH2, i.e., du.o(nitrate) > 4u.o(water) thus the nitrate anions are in an outer coordination sphere. 

Horwitz, E. R, Dietz, M. L., Fisher, D. E., Extraction of strontium from nitric acid solutions using dicyclohexano-18-crown-6 and its derivatives, Solv. Extr. Ion Exch., 8, 557-572,1990. 

The extraction of U022+ from nitric acid solutions by the shorter alkyl chain organophosphate HDBP has been investigated in various diluents by Hardy.117 The variation of D,jvi with nitric acid concentration for U022+ extraction into 0.01 M and 0.05 M HDBP in toluene is shown in... 

Suzuki, S., Tamura, K., Tachimori, S., Usui, Y. 1999. Extraction of uranium(VI) and plutonium(IV) from nitric acid solution by substituted cyclic amides. Solvent Extr. Res. Dev. Jpn. 6 72-79. 

Spjuth, L., Liljenzin, J.-O., Skalberg, M. et al. 1997. Extraction of actinides and lanthanides from nitric acid solution by malonamides. Radiochim. Acta 78 39 16. 

Chan, G.Y.S., Drew, M.G.B., Hudson, M.J. et al. 1997. Solvent extraction of metal ions from nitric acid solutions using N,N -substituted malonamides. Experimental and crystallographic evidence for two mechanisms of extraction, metal complexation and ion-pair formation. J. Chem. Soc. Dalton Trans. 1997 (4) 649-660. 

Nakamura, T., Miyake, C. 1995. Extraction of lanthanide(III) and uranyl(VI) from nitric acid solution by N,N -dimethyl-N,N -dibutylmalonamide. Solvent Extr. Ion Exch. 13 (2) 253-273. 

Tachimori, S., Sato, A., Nakamura, H. 1978. Extraction of lanthanides(III) with di-Ao-decyl phosphoric acid from nitric acid solution. J. Nucl. Sci. Technol. 15 421 -25. 

Babain, V.A., Alyapyshev, M.Yu., Kiseleva, R.N. 2007. Metal extraction by N,N -dialkyl-N,N -diaryl-dipicolinamides from nitric acid solutions. Radiochim. Acta 95 (4) 217-223. 

Tachimori, S., Suzuki, Y., Sasaki, Y., Apichaibukol, A. 2003. Solvent extraction of alkaline earth metal ions by diglycolic amides from nitric acid solutions. Solvent Extr. Ion Exch. 21 (5) 707-715. 

Lin, Y. Smart, N.G. Wai, C.M. Supercritical fluid extraction of uranium and thorium from nitric acid solutions with organophosphorus reagents, Environ. Sci. Tech. 29 (1995)... 

Patil, C.B. Mohapatra, P.K. Singh, R.R. Gurba, P.B. Janardan, P. Changrani, R.D. Manchanda, V.K. Transport of uranium from nitric acid solution by non-dispersive solvent extraction using a hollow fibre contactor, Radiochim. Acta 94 (2006) 331-334. 

The ZEALEX Process Researchers from KRI have shown that the zirconium salt of dibutyl phosphoric acid (ZS-HDBP) was soluble in Isopar-L in the presence of 30% TBP. This super PUREX solvent, known as ZEALEX, extracts actinides (Np-Am) together with lanthanides and other fission products, such as Ba, Cs, Fe, Mo, and Sr from nitric acid solutions. The extraction yields depend on both the molar ratio between Zr and HDBP in the 30% TBP/Isopar-L mixture and the concentration of HN03 (232). Trivalent transplutonium and lanthanide elements can be stripped together from the loaded ZEALEX solvent by a complexing solution, mixing ammonium carbonate, (NH4)2C03, and ethylenediamine-N.N.N. N -tetraacetic acid (EDTA). An optimized version of the process should allow the separation of... 

This difference of behavior of calixarenes bearing CMPO residues either on the wide rim or on the narrow rim was confirmed by extraction of europium (from nitric acid solutions by CPw2 and CPn2 diluted in chloroform) by implementing ESI-MS for the two calixarenes. Complexes with 1 1 and 1 2 Eu calix-CMPO stoichiometry were evidenced. The major species for CPw2 is the 1 2 complex, while for CPn2 the predominant complex is the 1 1 complex.165... 

Turanov, A.N. Karandashev, V.K. Baulin, V.E. Extraction of man and thorium with neitral phosphoryl containing podands from nitric acid solutions. Radiokhim. (Russ.) 1998,40(1), 36 13. 

Kyrs, M., Svoboda, K., Lhotak, P., Alexova, J. Solvent extraction of europium from nitric acid solutions into chlorobenzene in the presence of calixarenes and dicarbollides. J. Radioanal. Nucl. Chem. (2002), 254 (3), 455 -64. 

Shmidt, O.V., Zilberman, B.Ya., Fedorov, Yu.S., Suglobov, D.N., Puzikov, V.A., Mashkov, L.G., Palenik, Yu.V., Glekov, R.G. Extraction properties of dibutylphosphoric acid zirconium salt in recovery of transplutonium and rare-earth elements from nitric acid solution. Radiokhimiya (2002), 44 (5), 428 133. 

The variation of strontium distribution ratios DSr from nitric acid solution was investigated as a function of the irradiation dose. In toluene DCH18C6 solution, DSl was minimally affected by radiolysis, but decreased with the absorbed dose in the other nonaromatic solvents (254). Nevertheless, the distribution ratios measured after radiolysis were higher than expected, given the remaining extractant concentration, indicating some contribution from the degradation products (e.g., after an irradiation of 0.84 MGy, 70% of the crown ether was destroyed in chloroform, while the distribution ratio exhibited a decrease of only 30%) (254). 

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