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Caustic Treatment of Zircon in the Preparation of Pure Zirconium Compounds

Description: From abstract: This investigation was conducted in order to develop a process whereby the most abundant zirconium ore, namely zircon, could economically be put into solution and purified adequately for use in hafnium separation processes employing liquid-liquid extraction. Secondary aims concerned the preparation of pure zirconyl chloride, zirconyl nitrate, zirconyl sulfate, and zirconium oxide from the zircon ore.
Date: June 23, 1953
Creator: Spink, Donald R. & Wilhelm, Harley A.
Partner: UNT Libraries Government Documents Department

Report on Zirconium Nitride

Description: Report presenting the properties and method of preparation of zirconium nitride, a compound that was being considered for use in high temperatures due to its high melting point and hardness.
Date: November 11, 1947
Creator: Hall, George D.
Partner: UNT Libraries Government Documents Department

Delta-Phase Zirconium Hydride as a Solid Moderator

Description: Abstract: "In a study of the preparation and properties of delta-phase zirconium hydride it was found that large, sound bodies of the hydride can be prepared by direct combination of the elements if the rate of the reaction is retarded by limiting the supply of available hydrogen. Specimens up to 1-in. diameter were prepared using this technique. Because delta phase zirconium hydride does not readily form eutectics with iron-and nickel-base alloys below 1800 F these materials may be utilized for clodding the hydride. Delta-phase zirconium hydride is unaffected by exposure to liquid NaK or to nitrogen gas at temperatures below 1000 F. The hot hardness of delta-phase zirconium hydrid is about 130 kg per mm-2 at room temperature and 40 kg per mm-2 at 1500 F. The mean coefficient of thermal expansion (68 to 1337 F) is 6.5 x 10^-6 per deg F. The thermal conductivity varies from 5.7 Btu/(ft)(hr)(F) at 300 F to 5.1 Btu/(ft)(hr)(F) at 1300 F."
Date: December 18, 1957
Creator: Vetrano, James B.
Partner: UNT Libraries Government Documents Department

Effect of Fluoride on the Gravimetric Determination of Zirconium in Zirconium Fluoride

Description: Abstract: "The results of this investigation that it is necessary to remove fluoride prior to precipitation zirconium with mandelic acid or phenyl arsonic acid. Fluoride, however, has little effect on the cupferron method of precipitation. The discovery that zirconium fluoride is soluble in a mixture of aqua regia and sulfuric acid made it possible to dissolve the material without the addition of fluoride from hydrofluoric acid."
Date: June 3, 1952
Creator: McCutchen, R. L. & Susano, C. D.
Partner: UNT Libraries Government Documents Department

The Cladding of Delta-Phase Zirconium Hydride

Description: Abstract: A study has been made of the cladding of solid and powdered delta-phase zirconium hydride is both red and flat shapes with stainless steel. The program included investigations of metallurgical bonding, both with and without the sore of metallic barrier materials. Types 304 and 347 stainless steel were used for cladding material. The intermediate barrier-layer materials used were niobium, molybdenum, a combination of copper and molybdenum, and a combination of copper and niobium. The pressure-bonding techniques, involving the use of gas pressure at elevated temperatures, was employed in this study. Variable times and temperatures with a constant pressure of 10,000 poi were utilized by produce bonding. In this study, the best results were archived is cladding delta-phase zirconium hydride directly with Types 304 or 347 stainless steel. Good bonds were obtained by pressure bonding at 1600 F for 3 or 4 hr subsequent to pressure bonding at 1900 F for 1 to 2 hr at a pressure of 10,000 poi. Partial bonding was achieved between niobium and zirconium hydride and molybdeum and girconium hydride.
Date: December 27, 1957
Creator: Paprocki, Stan J.; Hodge, Edwin S. & Boyer, Charles B.
Partner: UNT Libraries Government Documents Department

Recovery of Zirconium Tetrachloride Powder

Description: Report discussing methods for recovering hafnium-free zirconium from irradiated fuel elements. Two methods are discussed: the fluoride method and the Zircex method. Experimental procedures to evaluate these methods and their results are presented.
Date: April 6, 1956
Creator: Lee, L. A. & Welt, M. A.
Partner: UNT Libraries Government Documents Department

Ultra-thin multilayer capacitors.

Description: The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.
Date: June 1, 2009
Creator: Renk, Timothy Jerome & Monson, Todd C.
Partner: UNT Libraries Government Documents Department

Polypropylene reinvented: Costs of using metallocene catalysts

Description: This study develops scoping estimates of the required capital investment and manufacturing costs to make a zirconocene catalyst/cocatalyst system [(F{sub 6}-acen)Zr(CH{sub 2}CMe{sub 3})(NMe{sub 2}Ph)][B(C{sub 6}F{sub 5}){sub 4}] immobilized on a silica support. Costs for this fluorine-based system are compared with estimates for two other metallocene catalysts using methylaluminoxane (MAO)-based cocatalysts. Including wt of support and cocatalyst, each of the production facilities for making the 3 zirconocene catalyst systems is sized at 364--484 tonnes/year. Cost to make the F-based catalyst system is estimated to be $10780/kg, assuming 20% return on capital invested. Costs for the two MAO-based catalyst system fall in the range of $10950--12160/kg, assuming same return. Within the {plus_minus}50% accuracy of these estimates, these differences are not significant. Given a catalyst productivity of 250 kg resin/gram zirconocene, the cost contribution in the finished ethylene-propylene copolymer resin is 4.4 cents/kg, excluding selling, administrative, research costs.
Date: May 1, 1996
Creator: Brockmeier, N.F.
Partner: UNT Libraries Government Documents Department

Zirconium-Hafnium Separation : Mixer-Settler Studies : Final Report

Description: Abstract: Use of the mixer-settler apparatus as a rapid means of determining improved conditions for plant operation is described including the experimental details. The preparation of highly purified samples of both zirconium oxide and hafnium oxide is discussed. (This document is concerned almost entirely with explorations of small scale continuous systems. Another document dealing with this general problem using small scale batch operations is being published simultaneously. It should prove of advantage to the reader to study this companion report, Document Y-611, by Barton, Overholser, and Grimes, to obtain a complete picture of the available information.).
Date: November 17, 1955
Creator: Waldrop, F. B.; Ward, W. T. & Leaders, W. M.
Partner: UNT Libraries Government Documents Department

Technical Foundations of TRIGA

Description: From foreword: The TRIGA is a novel and unusually safe training, research, and isotope-production reactor that contains solid homogeneous uranium-zirconium-hydride-moderator fuel elements and operates at power levels in the range of from 10 kw to 250 kw.
Date: August 27, 1958
Creator: General Dynamics Corporation. General Atomic Division
Partner: UNT Libraries Government Documents Department

Scoping corrosion tests on candidate waste package basket materials for the Yucca Mountain Project

Description: A scoping corrosion test was performed on candidate waste package basket materials. The corrosion medium was a pH-buffered solution of chemical species expected to be produced by radiolysis. The test was conducted at 90{degrees}C for 96 hours. Samples included aluminum-, copper-, stainless steel-, and zirconium-based metallic materials and several ceramics, incorporating neutron-absorbing elements. Sample weight losses and solution chemical changes were measured. Both corrosion of the host materials and dissolution of the neutron- absorbing elements were studied. The ceramics and the zirconium-based materials underwent only minor corrosion. the stainless steel-based materials performed well except for a welded sample. The aluminum- and copper-based materials exhibited the highest corrosion rates. Boron dissolution depends on it chemical form. Boron oxide and many metal borides dissolve readily in acidic solutions while high- chromium borides and boron carbide, though thermodynamically unstable, exhibit little dissolution in short times. the results of solution chemical analyses were consistent with this. Gadolinium did not dissolve significantly from monazite, and hafnium showed little dissolution from a variety of host materials, in keeping with its low solubility.
Date: March 1, 1998
Creator: Van Konynenburg, R.A.; Curits, P.C. & Summers, T.S.E.
Partner: UNT Libraries Government Documents Department

Plasma enhanced chemical vapor deposition of ZrO{sub 2} thin films

Description: Amorphous ZrO{sub 2} thin films were deposited in an inductively coupled PECVD system using a Zr {beta}-diketonate, Zr(C{sub 11}H{sub 19}O{sub 2}){sub 4}, as the precursor. The deposits were air annealed at 900C for 5 min to get pure, single phase, oriented, polycrystalline {alpha}-ZrO{sub 2}. Feasibility of using 2 different types of reactors was investigated. The inductively heated horizontal reactor depositions at 600C had a lower deposition rate and the films were non-uniform in thickness with a columnar structure. The resistively heated vertical reactor depositions at 350C had a higher deposition rate and the films were more uniform in thickness with a fine grained microstructure. The statistical design was demonstrated as an effective technique to analyze the effect of process conditions on the rate of deposition and relative (h00) orientation. The factorial design was used to quantify the two responses in terms of the process variables and their mutual interactions. The statistical design for rate of deposition was found to correlate with the trends observed in classical design.
Date: December 9, 1993
Creator: Saravanan, Kolandaivelu
Partner: UNT Libraries Government Documents Department

Fractal Polyzirconosiloxane Cluster Coatings

Description: Fractal polyzirconosiloxane (PZS) cluster films were prepared through the hydrolysis-polycondensation-pyrolysis synthesis of two-step HCl acid-NaOH base catalyzed sol precursors consisting of N-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole, Zr(OC{sub 3}H{sub 7}){sub 4}, methanol, and water. When amorphous PZSs were applied to aluminum as protective coatings against NaCl-induced corrosion, the effective film was that derived from the sol having a pH near the isoelectric point in the positive zeta potential region. The following four factors played an important role in assembling the protective PZS coating films: (1) a proper rate of condensation, (2) a moderate ratio of Si-O-Si to Si-O-Zr linkages formed in the PZS network, (3) hydrophobic characteristics, and (4) a specific microstructural geometry, in which large fractal clusters were linked together.
Date: August 1, 1992
Creator: Sugama, T.
Partner: UNT Libraries Government Documents Department

Investigation of poling processor, charge trapping and preservation - some ferroelectric and polymeric material. Final report, July 1, 1984--June 20, 1990

Description: A single crystalline (Yttrium stabilized) Zirconia was extensively studied in order to get insight into the charge transport process in Zirconia as compared to other crystalline samples. One thing examined was the effect of crystalline-orientation charge retention on the electret formation discs. The authors did not find any significant difference in the electret formation or retention on cutting the crystal in different orientations. They did, however, notice and collect data on the increase of the charge density and the half life when the sample thickness was increased. They are trying to correlate this with their theory developed for the charge retention and relaxation for the two different mechanisms of monocharge and bipolar charge retention. They also examined the increase in the relaxation time by storage at colder temperature and drier atmosphere. The result was an exponential increase of the half life with the fall of temperature as expected. They began investigating different new materials, all obtained from single crystalline structure. Some new materials like deuterated triglycine fluoroberyliate, (TGA) etc., were found to have much lower insulation property to be able to retain the charges. On the other hand the single crystalline samples of Lithium Niobate and lead zirconium titanate were found to be much better than the single crystal-zironia.
Date: September 1, 1997
Partner: UNT Libraries Government Documents Department

Mixed metal phospho-sulfates for acid catalysis

Description: Mixed metal phospho-sulfates have been prepared and evaluated for use as acid catalysts via 2-methyl-2-pentene isomerization and o-xylene isomerization. Particular members of this class of materials exhibit greater levels of activity than sulfated zirconia as well as lower rates and magnitudes of deactivation. {sup 31}P MAS NMR has been used to examine the role of phosphorus in contributing to the activity and deactivation behavior of these materials, while powder x-ray diffraction, BET surface area, IR, and elemental analysis were used to characterize the bulk catalysts.
Date: December 1, 1997
Creator: Thoma, S.G.; Jackson, N.B.; Nenoff, T.M. & Maxwell, R.S.
Partner: UNT Libraries Government Documents Department


Description: Process and product requirements to be met in the fabrication of Type 3 fuel elements are presented. The fuel elements specified consist of thin plates of a dispersion of highly enriched UO/sub 2/ and ZrB/sub 2/ in a stainless steel matrix which is clad with stainless steel on all surfaces. Quality assurance provisions are discussed. Process and material specifications and packaging and packing for shipment are described. Sample calculations and drawings are included. (M.C.G.)
Date: April 27, 1962
Creator: Edgar, E.C. & Clayton, H.R.
Partner: UNT Libraries Government Documents Department


Description: The feasibility of the containment of a molten sodium fluoride- zirconium fluoride salt at 550 deg C in vessels with a protective inner liner of frozen salt of the same composition was demonstrated. Two different designs were used for supplying internal heat directly to the molten salt: induction heating and electrolytic heating. The test equipment was of a size practical for processing zirconiumuranium alloy reactor fuel by the Fused Salt Process. (auth)
Date: August 1, 1961
Creator: Kessie, R.W.; Gabor, J.D.; Mecham, W.J. & Jonke, A.A.
Partner: UNT Libraries Government Documents Department


Description: Continuous dissolution of Zircaloy-2 in a titanium dissolver appears practical using as a dissolvent refluxing 3 M HNO/sub 2/-l.2 M HF--0.4 M HBF/sub 4/-0.6 M Cr(III)-0.4 M Cr(VI)--0.46 M Zr. Dissolution and corrosion rates were 10 mg/cm/sub 2/-min and 0.0 mil/mo in short term tests, respectively. A stable product solution containing 0.36 M Zr was obtained after addition of aluminum nitrate to complex fluoride ion. Another reagent investigated for use in continuous dissolution was 16 M HNO/sub 3/-2.6 M F-0.025 M HBF/sub 4/-1.4 M Zr with short term titanium corrosion rates of 0.0 mil/mo. However, Zircaloy-2 dissolution rates were only 3 mg/cm/sup 2/-min in the latter reagent. (auth)
Date: October 11, 1961
Creator: Gens, T.A.
Partner: UNT Libraries Government Documents Department

Study of ZrCl by self-consistent band calculation

Description: A nonrelativistic self-consistent electronic band structure calculation has been performed on zirconium monochloride using the KKR method. The exchange potential was approximated by the X..cap alpha.. method. The compound contains homoatomic layers in the sequence Cl--Zr--Zr--Cl and has the characteristics of a graphite-like two-dimensional metal. A substantial charge transfer is found toward the metallic layers and away from the loosely bonded halogen layer. There is also significant admixture of Zr-d character within the filled Cl-3p bands. The total density of states is in good agreement with the valence band photoemission results.
Date: July 1, 1979
Creator: Marchiando, J.F.
Partner: UNT Libraries Government Documents Department