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Application of Ascorbic Acid Method to Uranium in Salvage Solutions

Description: Abstract: The erroneously high values for uranium content of salvage solutions as determined by the ether extraction-ascorbic acid procedure have been demonstrated to be due to the presence of colored organic materials in these solutions. Evaporation of such solutions to fumes of HC104 before extraction has been shown to be completely successful in preventing such interference while pretreatment with activated carbon is sufficiently successful for application in Control laboratories. Complete procedures for application of either protreatment and results of such application to composite salvage solutions received over a six-month period are included.
Date: June 11, 1947
Creator: Rothenberger, C. D. & Grimes, W. R.
Partner: UNT Libraries Government Documents Department

A Miniature Mixer Settler

Description: Unit developed at Knolls Atomic Power Laboratory for extraction and overcomes the disadvantages of the batch countercurrent units currently in use.
Date: January 5, 1956
Creator: Alter, H. Ward
Partner: UNT Libraries Government Documents Department

Factors Affecting the Extraction of Uranium with Dibutyl Carbitol

Description: Abstract: "This is a compilation of the material in several reports on the extraction of uranium from aqueous solutions with dibutyl carbitol. Data is presented concerning the optimum conditions for the extraction of the uranium and elimination of impurities."
Date: July 8, 1946
Creator: Weaver, Boyd S. & Larson, C. E.
Partner: UNT Libraries Government Documents Department

Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

Description: This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University developed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter Laboratory efforts were coordinated in complementary fashion with engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.
Date: July 1, 2013
Creator: Duncan, Nathan C; Delmau, Laetitia Helene; Ensor, Dale; Lee, Denise L; Birdwell Jr, Joseph F; Hill, Talon G et al.
Partner: UNT Libraries Government Documents Department

Recommended Guanidine Suppressor for the Next-Generation Caustic-Side Solvent Extraction Process

Description: The guanidine recommended for the Next-Generation Caustic-Side is N,N ,N -tris(3,7-dimethyloctyl)guanidine (TiDG). Systematic testing has shown that it is significantly more lipophilic than the previously recommended guanidine DCiTG, the active extractant in the commercial guanidine product LIX -79, while not otherwise changing the solvent performance. Previous testing indicated that the extent of partitioning of the DCiTG suppressor to the aqueous strip solution is significantly greater than expected, potentially leading to rapid depletion of the suppressor from the solvent and unwanted organic concentrations in process effluents. Five candidate guanidines were tested as potential replacements for DCiTG. The tests included batch extraction with simulated waste and flowsheet solutions, third-phase formation, emulsion formation, and partition ratios of the guanidine between the solvent and aqueous strip solution. Preliminary results of a thermal stability test of the TiDG solvent at one month duration indicated performance approximately equivalent to DCiTG. Two of the guanidines proved adequate in all respects, and the choice of TiDG was deemed slightly preferable vs the next best guanidine BiTABG.
Date: January 1, 2013
Creator: Moyer, Bruce A; Delmau, Laetitia Helene; Duncan, Nathan C; Ensor, Dale; Hill, Talon G; Lee, Denise L et al.
Partner: UNT Libraries Government Documents Department

Solvent Blending Strategy to Upgrade MCU CSSX Solvent to Equivalent Next-Generation CSSX Solvent

Description: The results of the present study have validated an equal-volume blending strategy for upgrading freshly prepared CSSX solvent to a blended solvent functionally equivalent to NG-CSSX solvent. It is shown that blending fresh CSSX solvent as currently used in MCU with an equal volume of an NG-CSSX solvent concentrate of appropriate composition yields a blended solvent composition (46.5 mM of MaxCalix, 3.5 mM of BOBCalixC6, 0.5 M of Cs-7SB, 3 mM of guanidine suppressor, and 1.5 mM of TOA in Isopar L) that exhibits equivalent batch ESS performance to that of the NG-CSSX solvent containing 50 mM of MaxCalix, 0.5 M of Cs-7SB, and 3 mM of guanidine suppressor in Isopar L. The solvent blend composition is robust to third-phase formation. Results also show that a blend containing up to 60% v/v of CSSX solvent could be accommodated with minimal risk. Extraction and density data for the effect of solvent concentration mimicking diluent evaporation or over-dilution of the equal-volume blended solvent are also given, providing input for setting operational limits. Given that the experiments employed all pristine chemicals, the results do not qualify a blended solvent starting with actual used MCU solvent, which can be expected to have undergone some degree of degradation. Consequently, further work should be considered to evaluate this risk and implement appropriate remediation if needed.
Date: December 1, 2012
Creator: Delmau, Laetitia Helene & Moyer, Bruce A
Partner: UNT Libraries Government Documents Department

Distribution of selected lanthanides and actinides between 30% TBP in n- paraffin and various metal nitrate solutions

Description: Distributions were measured for nitric acid, americium, curium, cerium, neodymium, samarium, europium, manganese, and mercury between 30 vol % THP in n- paraffin and aqueous solutions containing nitric acid, aluminum nitrate, lithium nitrate, and/or sodium nitrate. Equations for the distributions were derived from the data and used in designing solvent extraction flowsheets for recovery and decortamination of americium and curium from irradiated plutonium- aluminum alloy. Also investigated was the effect of DTPA acid on the distribution of the actinides and lanthanides in the same systems. The actinides (Am and Cm) are more strongly complexed than the light lanthanides (La, Ce, Pr, and Nd) by DTPA acid. By controlling the solution pH in the range of 1 to 3, separation of actinides from lanthanides by factors of 10 to 100 may be obtained by extraction with 30% THP. (auth)
Date: November 1, 1973
Creator: Thompson, M.C.
Partner: UNT Libraries Government Documents Department

Summary Report: AEC Reference Fuel-Processing Plant

Description: From introduction: The primary purpose of this report is to record the bases chosen in setting the Commission's policy on processing charges to assure that individual charges are on a consistent basis in conformance with the policy. Secondly, it may aid reactor operators in estimating the AEC processing charges for a variety of fuels and reactor conditions. It may also be of interest to potential chemical processors by showing the approach followed in developing these charges.
Date: October 1957
Creator: U.S. Atomic Energy Commission
Partner: UNT Libraries Government Documents Department

The Use of a Centrifugal Contactor for Component Concentration by Solvent Extraction

Description: Theoretical and experimental work was undertaken to explore the use of the Argonne design centrifugal contactor as a concentrating device for metal ions in solutions such as transuranic-containing waste streams and contaminated groundwater. First, the theoretical basis for operating the contactor as a concentrator was developed. Then, the ability of the contactor to act as a concentrating device was experimentally demonstrated with neodymium over a wide range of organic-to-aqueous (O/A) flow ratios (0.01 to 33). These data were also used to derive a correlation for the effect of O/A flow ratio on extraction efficiency.
Date: July 1992
Creator: Leonard, R. A.; Wygmans, D. G.; McElwee, M. J.; Wasserman, M. O. & Vandegrift, G. F.
Partner: UNT Libraries Government Documents Department

Separation of americium from europium by solvent extraction from aqueous phosphonate media

Description: Complexes between Am{sup 3+} or Eu{sup 3+} and phosphonoacetic acid differ in relative stability in accord with the electrostatic model of cation binding. The smaller Eu{sup 3+} cation forms stronger complexes with PAA than the larger Am{sup 3+} cation. The observed metal complexes in the acid range from 0.005 M to 0.02 M (at I= 0.5 M) are Eu(HL){sup +}, Eu(H{sub 3}L){sub 2}{sup +}, Eu(HL){sub 2}{sup {minus}} and Am(H{sub 2}L){sup 2+}, Am(HL){sup +}, Am(H{sub 2}L){sub 2}{sup +}. When used as a holdback reagent, PAA slightly enhances the separation of Am/Eu when used with sulfonic acids or CMPO/nitrate, but reduces separation efficiency with HDEHP. In a CMPO/SCN{sup {minus}} extraction system which favors extraction of Am over Eu, addition of PAA increases the separation efficiency by a factor of 2-3 at 0.3 M PAA/0.5 M SCN{sup {minus}}. The calculated stability constants can be used to explain the separation factors, but do not always accurately predict metal distribution ratios in the CMPO systems, implying that there are details of this system which have not been fully elucidated.
Date: December 31, 1994
Creator: Ensor, D.D. & Nash, K.L.
Partner: UNT Libraries Government Documents Department

Mixing quality characterization in separations process tanks

Description: An experimental study has been performed on distribution of a dilute immiscible organic liquid dispersed in an aqueous phase contained baffled, paddle-agitated vessel, fitted with cooling coils. Acceptable total liquid levels in the vessel and minimum impeller speed were established for plant scale operation. Axial and radial distributions of the dispersed organic phase as functions of total liquid height, impeller speed, and the number of impellers were examined and some recurring trends were identified. Four stages of dispersion of organic phase in predominantly aqueous phase were identified with increasing rotational speed of impeller(s). The stages were: (1) non-dispersion stage in which the organic layer was undisturbed, (2) the organic layer was decreasing with impeller speed until complete but nonuniform dispersion was attained, (3) the non-uniformity of the completely dispersed mixture decreased with increasing rotational speed of impeller(s), and (4) a grossly uniform dispersion in which the local volume fraction of dispersed phase (organic) in mixture was the same throughout the vessel. Scale-up relations were developed for reproducing a defined mixing quality on two geometrically similar scales of operation, for the attainable condition of complete but non-uniform dispersion. The mixing quality was observed to decrease with increasing liquid depth over acceptable range, but variations in the overall concentration of organic liquid appeared to have only slight effect on the mixing quality.
Date: January 31, 1995
Creator: Hassan, N.M.
Partner: UNT Libraries Government Documents Department

Combined solvent extraction-liquid scintillation methods for radioassay of alpha emitters

Description: Alpha emitting nuclides frequently can be separated from one another and from interfering ions by solvent extraction procedures. If the last step of such a scheme automatically incorporates the nuclide of interest in a liquid scintillator (containing an extractant), a simple procedure for radioassay of the nuclide results. It is shovwn that correct choices of scintillators and detector systems produce further advantages. Quenching is minimized and held constant, so that the pulse height obtained from a given alpha energy is reproducible, and the energy resolution is improved over that obtainable with conventional liquid scintillation methods, so that alpha peak widths are decreased from around 1 MeV to 0.2 to 0.3 MeV at half maximum. Compatibility of several extractants with scintillator solutions is described. Procedures are described for separation and analysis of several nuclides (e.g., plutonium, uranium, and tnivalent actinides), including a specific application to the assay of plutonium in enviromnental samples. (auth)
Date: January 1, 1974
Creator: McDowell, W.J. & Coleman, C.F.
Partner: UNT Libraries Government Documents Department

Complexation of Plutonium (IV) with Fluoride at Variable Tempeartures

Description: Complexation of Pu(IV) with fluoride was studied by solvent extraction at 25, 40 and 55 C in 2.2 mol {center_dot} kg{sup -1} HClO{sub 4}. The distribution ratio of Pu(IV) between the organic and aqueous phases decreased as the concentration of fluoride was increased due to the formation of Pu(IV)-F complexes in the aqueous phase. Two complexes, PuF{sup 3+} and PuF{sub 2}{sup 2+}, were identified under the conditions in this work and their stability constants at 25, 40 and 55 C and I = 2.2 mol {center_dot} kg{sup -1} HClO{sub 4} were determined from the distribution data. The Specific Ion Interaction approach (SIT) was used to extrapolate the constants to the state of infinite dilution. Data from this work indicate that the complexation of Pu(IV) with fluoride is endothermic and entropy-driven. The complexation becomes stronger at higher temperatures.
Date: June 10, 2009
Creator: Xia, Yuanxian; Rao, Linfeng; Friese, Judah I.; Moore, Dean A. & Bachelor, P. P.
Partner: UNT Libraries Government Documents Department