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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

Injection of Treated Wastewater for Ground-Water Recharge in the Palo Alto Baylands, California, Hydraulic and Chemical Interactions--Preliminary Report

Description: From Purpose and Scope: The objectives of this study are: (1) to define, both qualitatively and quantitatively, the clogging processes associated with injection, and (2) to determine the three-dimensional migration paths of injection water and native ground water.
Date: September 1983
Creator: Hamlin, Scott N.
Partner: UNT Libraries Government Documents Department

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

Calculated Equilibrium Distributions for the Uranyl Nitrate - Tributyl Phosphate - Dilute Nitric Acid System for Temperatures Between 25 and 75 C

Description: Report discussing the "equilibrium uranium distribution between an aqueous nitric acid solution and a 30 per cent by volume solution of tributyl phosphate in a hydrocarbon diluent" (p. 2). This includes the necessary equations.
Date: August 12, 1960
Creator: Wilburn, N. P.
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

Treatability Test Report: Characterization of Vadose Zone Carbon Tetrachloride Source Strength Using Tomographic Methods at the 216-Z-9 Site

Description: A treatability test was conducted in 2011 at the 216-Z-9 Trench to evaluate methods for collecting characterization information that supports refined assessment of SVE performance goals based on impact to groundwater. The characterization information can also provide input to operational strategies for continued SVE operation and decisions regarding closure of the SVE system or transition to other remedies, if necessary.
Date: September 28, 2012
Creator: Truex, Michael J.; Carroll, Kenneth C.; Rohay, Virginia J.; Mackley, Rob D. & Parker, Kyle R.
Partner: UNT Libraries Government Documents Department

Graph-Based Keyphrase Extraction Using Wikipedia

Description: Keyphrases describe a document in a coherent and simple way, giving the prospective reader a way to quickly determine whether the document satisfies their information needs. The pervasion of huge amount of information on Web, with only a small amount of documents have keyphrases extracted, there is a definite need to discover automatic keyphrase extraction systems. Typically, a document written by human develops around one or more general concepts or sub-concepts. These concepts or sub-concepts should be structured and semantically related with each other, so that they can form the meaningful representation of a document. Considering the fact, the phrases or concepts in a document are related to each other, a new approach for keyphrase extraction is introduced that exploits the semantic relations in the document. For measuring the semantic relations between concepts or sub-concepts in the document, I present a comprehensive study aimed at using collaboratively constructed semantic resources like Wikipedia and its link structure. In particular, I introduce a graph-based keyphrase extraction system that exploits the semantic relations in the document and features such as term frequency. I evaluated the proposed system using novel measures and the results obtained compare favorably with previously published results on established benchmarks.
Date: December 2010
Creator: Dandala, Bharath
Partner: UNT Libraries

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

A Vibration Model for Centrifugal Contactors

Description: Using the transfer matrix method, we created the Excel worksheet "Beam" for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k(sub B)) of a motor after measuring the k(sub B) value for three different motors. The k(sub B) value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.
Date: November 1992
Creator: Leonard, R. A.; Wasserman, M. O. & Wygmans, D. G.
Partner: UNT Libraries Government Documents Department