266 Matching Results

Search Results

Advanced search parameters have been applied.


Description: An economical process was developed through benchscale experiments for recovering uranium from amine extractants with ammonium carbonate solution. By recycling the strip solution to allow build-up in the concentration of ammonium sulfate (formed in the stripping reactions) to 1-2M, the solubility of uranium in the aqueous phase was limited to <5 g/liter and ammonium uranyl tricarbonate (AUT) precipitated in the stripping system. The AUT, which settled and filtered rapidly, was readily converted to U/sub 3/>i by calcination at 5OO deg C, yielding a high assay (>97% U/sub 3/O/sub 8/) concentrate virtually free of sodium, molybdenum, and vanadium. Estimated reagent costs for the strippingprecipitation step were 7 cent per pound of U/sub 3/O/sub 8/. (auth)
Date: March 1, 1961
Creator: Hurst, F.J. & Crouse, D.J.
Partner: UNT Libraries Government Documents Department

A Bibliography of Sources of Thermodynamic Data for the Systems: CO₂+NH₃+H₂O, CO₂+H₂S+H₂O, H₂S+NH₃+H₂O, and CO₂+NH₃+H₂S+H₂O

Description: Abstract: Contained herein is a bibliography of sources of experimental and correlated thermodynamic data for the systems: CO₂ + NH₃ + H₂O, CO₂ + H₂S + H₂O, H₂S + NH₃ + H₂O, and CO₂ + NH₃ + H₂S + H₂O. The types of data in this bibliography include all types of equilibrium data, including both eqilibria [sic] in solution and vapor-liquid equilibrium data, enthalpies, heat capacities, and densities. There are 215 references cited. Bibliographic Data Sheet.
Date: May 1985
Creator: Goldberg, Robert N. & Steckler, D. K.
Partner: UNT Libraries Government Documents Department

The MAP3S Aerosol Sulfate Acidity Network: A Progress Report and Data Summary, November 1981

Description: Abstract: A network of five atmospheric aerosol samplers was established in the northeastern US starting in February 1977. Size-fractionated samples of the aerosol were collected continuously with four-hour time resolution until the network was dismantled in February 1980. The aerosol-loading and aerosol-chemistry data obtained over this three-year period are summarized in this report. In particular, the samples were analyzed for the sulfate acidity of the aerosol. The acidity was found to be quite high over prolonged periods of time, with the monthly averaged acidity approaching that of ammonium bisulfate at several of the sites. Monthly, seasonal, daily, and diurnal variations in aerosol particle loading and acidity, and sulfate, ammonium, and nitrate ion concentrations are presented. The aerosol-chemistry data are tabulated separately for each of the sampling sites.
Date: November 1981
Creator: Johnson, S. A.; Kumar, R.; Cunningham, P. T. & Lang, T. A.
Partner: UNT Libraries Government Documents Department

Crystal Structure of a KPuO₂CO₃, NH₄ PuO₂CO₃, RbAmO₂CO₃

Description: From abstract: "The preceding article describes the preparation of a number of alkali carbonates of pentavalent neptunium, plutonium, or americium. The results of x-ray diffraction studies of some of these carbonate precipitates are presented in the present paper. The preparations to be dealt with are the K-Pu(V) (at low pH), NH4-Pu(V) and Rb-Am(V) precipitates which form one iso-structural series. In the case of the other preparations discussed in the preceding article, the x-ray work did not lead to reliable conclusions as to chemical formula and crystal structure."
Date: 1953
Creator: Ellinger, F. H. & Zachariasen, William H.
Partner: UNT Libraries Government Documents Department


Description: BS>The separation of rare earth mixtures by ion exchange using ammonium ethylenedisminetetracetate and annmonium N-hydroxyethylethylenediaminetriacetate as eluting agents is discussed in detail. Simple countercurrent separation theory is used to predict the minimum nuinber of displacements of an adsorbed band that are necessary in order to separate the components of binary mixtures. It is shown how the theory can be applied to even more complex systems, and experimental data are presented for some of the more difficultly separablc groups of rare-earth species. Experimental results agree very well with the theoretical predictions. (auth) A detailed description is presented of a process developed by Ames Laboratory for the separation of thorium, rare earths, and uranium from monazite sands. Oxalic acid is used to precipitate rare earths; and thorium from a sulfate and phosphate solution of these elements. The possibility of recovering uranium from the oxalate filtrate by anion exchange was investigated. (W.L.H.)
Date: January 1, 1956
Creator: Powell, J.E. & Spedding, F.H.
Partner: UNT Libraries Government Documents Department

Densities of Ammonium Fluoride-Ammonium Nitrate-Ammonium Hexafluozirconate Solutions

Description: The densities of various Zirflex-type solutions at 25 gas-cooled C can be expressed by the equation: p calc = (0.99710 + 0.03l57 m) + (0.02046 - 0.002659 m)c -(0.0033460.000703 m)c3/2 + 0.14349x + 0.49z where m = moles liter/ sup -1/ NH/sub 4/NO/sub 3/, c = moles liter/sup -1/ NH/sub 4/F, x = moles liter/ sup -1/ (NH/sub 4/)/sub 2/ZrF/sub 6/, and z = moles liter/sup -1/ UO/sub 2/(NO/ sub 3/)/sub 2/. This eq uation fits the data with a sigma value of 0.00018 g/ml for NH/sub 4/FNH/sub 4/NO/sub 3/ solutions, 0.00024 g/ml for NH/sub 4/F-(NH/sub 4/ )/sub 2/ZrF/sub 6/ solutions, and 0.0002 g/ml for solutions containing UO/sub 2/ (NO/sub 3/)/sub 2/ and/or NH/sub 4/F-NH/sub 4/NO/sub 3/ over the range of 0.0M to 6.0M NH/sub 4/F, 0.0M to 1.6M NH/sub 4/NO/sub 3/, 0.0M to 0.5M (NH/sub 4/)/sub 2/ ZrF/sub 6/, and 0.0M to 0.0025M UO/sub 2/(NO/sub 3/)/sub 2/. (auth)
Date: October 27, 1960
Creator: Teague, J. L. & Pearson, D. P.
Partner: UNT Libraries Government Documents Department


Description: An exothermic reaction was shown to take place between low temperature plutonium dioxide and ammonium bifluoride at 50 to 250 deg C, The reaction goes essentially to completion with the formation of the pink plutonium(IV) ammonium fluoride, This compound can be decomposed at 300 deg C and the resulting plutonium tetrafluoride dehydrated at 500 deg C. Analyses showed that plutonium tetrafluoride prepared in this manner is approximately 90% converted from the dioxide. On a twenty gram scale average reduction yields of over 97% can be obtained by reaction with metallic calcium in a hermetitally sealed, stationary bomb when a calcium-iodine booster is employed. (auth)
Date: March 16, 1954
Creator: Tolley, W.B.
Partner: UNT Libraries Government Documents Department


Description: BS>Experimental studies were performed to define the behavior in ammonium fluoride solutions of uraniumzirconium alloys and of explosive residues isolated from such alloys. The results indicate that once the diffusion layer existing between the uranium core and the Zircaloy cladrung is exposed to such solutions, it will readily and completely dissolve, thus eliminating the possibility of this portion of the diffusion layer entering into an explosive reaction with nitric acid. Because of the probability that the Zircaloy cladding (and, therefore, the diffusion layer) will not be completely removed from the uranium prior to the nitric acid core dissolution step, consideration was also given to the magnitude of a possible explosive reaction resulting from the exposure of the diffusion layer to nitric acid. It is concluded that the probability of an explosive reaction of sufficient magnitude to pressurize a dissolver during normal plant operations is very remote. (auth)
Date: September 30, 1959
Creator: Swanson, J.L.
Partner: UNT Libraries Government Documents Department

The Zirflex Process

Description: tive dissolution of zirconium or Zircaloy fuel cladding. The process involves the dissolution of the cladding material in solutions of ammonium fluoride alone or in mixture with amonium nitrate. Mixtures of amonium fluoride and amonium nitrate are preferred since they result in very little evolution of hydrogen during the is that these solutions attack austenitic stainless steels only slowly, in sharp contrast to the media (e.g., hydrofluoric acid or hydrofluoric-nitric acid mixtures) generng 6 M NH/sub 4/F, the rate of pentration of Zircaloy-2 is nearly 100 mils/hr, while that of typical austentic stainless steels is only about 0.5 mil/month. (auth)
Date: October 31, 1958
Creator: Swanson, J. L.
Partner: UNT Libraries Government Documents Department

Design and Evaluation of Ionic Liquids as Novel CO2 Absorbents

Description: Progress from the third quarter 2006 activity on the project ''Design and Evaluation of Ionic Liquids as Novel CO{sub 2} Absorbents'' is provided. Major activities in two areas are reported: property measurement and molecular modeling. We have measured CO{sub 2} solubility in an ammonium lactate ionic liquid. Previous work has shown that the lactate anion enables chemical complexation to occur. We hypothesized that the lactate anion would not be as effective in complexing when paired with an ammonium cation as compared to when it is paired with an imidazolium cation. The results confirm this. We also measured CO{sub 2} solubility in a functionalized ionic liquid containing an amine group. These so-called task specific ionic liquids (TSILs) are expected to have dramatically higher CO{sub 2} solubility than physical absorbents. We report isotherms as well as entropies and enthalpies of absorption for CO{sub 2} in one TSIL. CO{sub 2} solubilities are higher in this compound than in any previous IL we have observed. Finally, we also developed a new simulation method that will enable us to compute full isotherms of gases in ionic liquids. So far, we have tested the method against model systems and found it to be highly effective.
Date: September 30, 2006
Creator: Maginn, Edward J.
Partner: UNT Libraries Government Documents Department


Description: The results of laboratory studies on sodium carbonate ion exchange are shown. The effect of salt concentration, uranium concentration, and possible interference with ion exchange from vanadium, molybdenum, sulfate and chloride are discussed. Various elution systems and the effect of residual uranium are described. A short discussion of ammonium carbonate ion exchange is also presented. (auth)
Date: May 1, 1958
Creator: Hollis, E.T.
Partner: UNT Libraries Government Documents Department