On the Use of Quaternary Ammonium Nitrates

Shabana, R.; Ruf, H.

doi:10.1524/ract.1976.23.34.148

Cited by 9 publications

(4 citation statements)

References 8 publications

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“…The extraction of tervalent americium by quaternary ammonium salts from acidic nitrate medium has been reported by several workers [3][4][5][6][7][8][9][10]. The extraction studies of Am(III) from thiocyanate media by mixtures of Aliquat 336 and neutral donors like TOPO, TBPO and TBP have been investigated from pH = 2.5 solution [11],…”

Section: Introductionmentioning

confidence: 99%

Synergistic Extraction of Americium(III) by the Mixture of Aliquat 336 and TOPO from Acidic Nitrate Medium

1996

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The extent of synergism in case of the extraction of Americium(III) by the mixture of Aliquat 336 nitrate and TOPO, increases with increase in TOPO concentration. The increase in lanthanide concentration reduces the distribution ratio of Am(III) with the binary mixture of Aliquat 336 nitrate and TOPO. The negative enthalpy change and negative entropy change in the synergistic extraction confirm the adduct formation mechanism.

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Section: Introductionmentioning

confidence: 99%

Synergistic Extraction of Americium(III) by the Mixture of Aliquat 336 and TOPO from Acidic Nitrate Medium

1996

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“…The partial replacement of an aqueous acidic solution by an organic polar additive, completely miscible with water, influences strongly the extraction process. The organic additive increases or decreases the extraction yield of cations [1 -3], Several studies concerning potential applications to liquid -liquid extractions have been published [1,2,[4][5][6][7], but the extraction behaviour of actinides from binary aqueous-organic solutions particularly by macrocyclic crown compounds has not yet been examined. This paper describes the extraction of plutonium(IV) at the tracer level into various organic solvents in the presence of dicyclohexano-18-crown-6 (DC18C6) from aquoorganic solutions.…”

Section: Introductionmentioning

confidence: 99%

Liquid-Liquid Extraction of Plutonium(IV) by Dicyclohexano-18-crown-6 from Aqueous-Organic Solutions

1993

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Extraction of Pu(IV) was examined in the presence of several polar water-miscible organic solvents like methanol, ethanol, isobutanol, dioxane, acetone, propylene carbonate (PC) and acetonitrile. The extraction increased several fold with concentrations (up to 30%) of acetonitrile, dioxane, ethanol and PC, but decreases with the addition of acetone, isobutanol and methanol. Maximum enhancement took place in presence of PC and acetonitrile.

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“…Separation methods based on extraction [18], on paperand thin layer-chromatographies [19], on extraction-chromatography and sorption on silica gel [21 ], as well as on precipitation and extraction have been published, but they are time consuming, require much manpower and manual operation, require elaborated chemical operations prior to the actual chemical separation, and suffer from the lack of cross-controls.…”

mentioning

confidence: 99%

Determination of the Distribution of Neptunium at Tracer Concentrations Among its Oxidation States in Aqueous Nitric Acid Media

Toeroek¹,

Ruf²

1982

Radiochimica Acta

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A method has been worked out to determine quantitatively trace amounts of neptunium-ions of different oxidation states. The procedure is based on the selective retention of neptunium(IV) on Hydrated Antimony Pentoxid (HAP) as well as on the disproportionation of neptunium(V) in a second aliquot. Quantitative determination is performed by means of radiometric analysis, if necessary after neutron activation. Neptunium(VI) can be calculated from the material balance after determining the total amount of neptunium: Np(VI) = Np total -Np(V)-Np(IV). The reproducibility is better than 5 %. The deviation of the results from those obtained by the method of FOTI and FREILING [22] is less than 10%abs.The +4, +5 and +6 oxidation states of neptunium can be simultaneously found in diluted nitric acid solutions, e.g., in the process stream of nuclear reprocessing plants. This may be explained by the numerous redox processes which may run as parallel and consecutive pathways, e.g., disproportionation of neptunium [1,2], redox reactions induced by irradiation or by photochemical processes [5,8], reactions between Np(IV) on one side and Pu(IV) [9], Pu(VI) [10], Np(VI) [10] or Fe(III) [11 ] on the other side. In this way slight changes in the experimental conditions or in the technological parameters may have very profound effects on the reaction rates and on the position of equilibria. For this reason fast analytical techniques are required to determine the oxidation state of trace amounts of neptunium, and chemical separation procedures should be avoided. NMR-methods [12] and spectrophotometry techniques[13]fulfill these requirements, but the sensitivity is not sufficient for the analysis of solutions with a neptunium content of 1 μg/ cm 3 and below, which holds also for most of the methods used for overall neptunium analysis. This is why separation techniques could not be omitted, and a composite method had to be designed.As far as quantitative analysis is concerned, neutron activation analysis seemed to be one of the best choices, as the technique proved to be rather effective for the analysis of total neptunium [14][15][16][17], and the counting technique can also be used for radiometric analysis in process control.The development of an oxidation state separation scheme at the tracer level is beset not only with the well known difficulties of sorption, formation of radiocolloids, etc., but also with problems caused by the sensitive redox system to be dealt with. (In the presence of oxidizable or reducible substances, e.g., extracting agents or organic ionexchangers, one has to bear in mind possible reactions with the reagent!). The separation should therefore be as fast as possible, with an option for remotely controlled operation.Separation methods based on extraction [18], on paperand thin layer-chromatographies [19], on extraction-chromatography and sorption on silica gel [21 ], as well as on precipitation and extraction have been published, but they are time consuming, require much manpower and manual operation, require el...

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On the Use of Quaternary Ammonium Nitrates

Cited by 9 publications

References 8 publications

Synergistic Extraction of Americium(III) by the Mixture of Aliquat 336 and TOPO from Acidic Nitrate Medium

Synergistic Extraction of Americium(III) by the Mixture of Aliquat 336 and TOPO from Acidic Nitrate Medium

Liquid-Liquid Extraction of Plutonium(IV) by Dicyclohexano-18-crown-6 from Aqueous-Organic Solutions

Determination of the Distribution of Neptunium at Tracer Concentrations Among its Oxidation States in Aqueous Nitric Acid Media

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