402 Matching Results

Search Results

Advanced search parameters have been applied.

A Thermal Type Flow Meter for Low Flow Rates of Anhydrous Hydrofluoric Acid

Description: Report discussing a thermal type flow meter which was adapted for metering anydrous hydrofluoric acid at low flow rates. Corrosive gases, which are not appropriate for handling in standard type rotameters or orifice meters, are also suitable for this thermal type flow meter.
Date: June 24, 1946
Creator: Johnsson, Karl Otto; Peed, W. F. & Clewett, G. H.
Partner: UNT Libraries Government Documents Department

Separation of Metal Ions by Anion Exchange in Mixtures of Hydrochloric Acid and Hydrofluoric Acid

Description: Distribution coefficients were determined for the adsorption of more than 40 elements on anion-exchange resins from mixtures of HCl (0.1 to 12M) and HF (0.1-8M). Two resins, Dowex 1 x 10, 200 to 400 mesh and Dowex 1 x 4, 100 to 200 mesh, were used. Distribution coefficients were also determined for the adsorption of many elements on both resins from 0.1 to 12M HCl and 0.1 to 12M HF. Anion exchange in the presence of HF was found useful for separating impurities from various materials for their subsequent determination, and specific procedures used in our spectrochemical laboratory for this purpose are outlined. The results of a literature search on the use of anion exchange in hydrofluoric acid and fluoride-containing media are presented in an extensive bibliography.
Date: December 1978
Creator: Faris, J. P.
Partner: UNT Libraries Government Documents Department

Chambers Works Process for the Manufacture of Fluorine in East Area Carbon Anode Cells (M.W.38.0)

Description: Historical: This process is based on experimental work done in Jackson Laboratory, Send Works, Blue Products, and East Area. It supersedes the Tentative Chambers Works Process for the Manufacture of Fluorine Using Carbon Anode Units, dated December 2, 1943.
Date: January 18, 1948
Creator: E. I. du Pont de Nemours & Company
Partner: UNT Libraries Government Documents Department

CORROSION ASSOCIATED WITH HYDROFLUORINATION IN THE OAK RIDGE NATIONAL LABORATORY FLUORIDE VOLATILITY PROCESS

Description: Studies carried out on corrosion associated with the hydrofluorination- dissolution phase in the fused-salt Fluoride Volatility Process are summarized. Corrosion for hydrofluorination-dissolver vessels used in bench-scale and semiworks-scale process development at ORNL is discussed. The results of a study on construction materials for the dissolution phase are presented. Corrosion studies at ANL are described for comparison purposes. A full-size hydrofluorinator dissolver is described. (M.C.G.)
Date: November 15, 1961
Creator: Goldman, A.E. & Litman, A.P.
Partner: UNT Libraries Government Documents Department

A new device for filtering hydrofluoric acid and other strong acids. Information report

Description: During the course of a research problem involving hydrofluoric acid it became necessary to filter concentrated hydrofluoric solutions to remove various solid materials. The search for a suitable filter media finally led to the use of a commercially manufactured plastic material known as ``Sponge Teflon`` (polytetrafluoroethylone) which is produced by the DuPont Company. This material, which comes in 1/8 in. sheets, is used primarily as a gasket material in acid lines, and is impervious to all acids, including hydrofluorle acid.
Date: July 9, 1948
Creator: Bell, R.
Partner: UNT Libraries Government Documents Department

Environmentally Assisted Cracking of Commercial Ni-Cr-Mo Alloys - A Review

Description: Nickel-Chromium-Molybdenum alloys (Ni-Cr-Mo) are highly resistant to general corrosion, localized corrosion and environmentally assisted cracking (EAC). Cr acts as a beneficial element under oxidizing acidic conditions and Mo under reducing conditions. All three elements (Ni, Cr and Mo) act synergistically to provide resistance to EAC in environments such as hot concentrated chloride solutions. Ni-Cr-Mo alloys may suffer EAC in environments such as hot caustic solutions, hot wet hydrofluoric acid (HF) solutions and in super critical water oxidation (SCWO) applications. Not all the Ni-Cr-Mo alloys have the same susceptibility to cracking in the mentioned environments. Most of the available data regarding EAC is for the oldest Ni-Cr-Mo alloys such as N10276 and N06625.
Date: November 9, 2004
Creator: Rebak, R B
Partner: UNT Libraries Government Documents Department

Prediction of release-etch times for surface-micromachined structures

Description: A one-dimensional model is presented which describes the release-etch behavior of sacrificial oxides in aqueous HF. Starting from first principles and an empirical rate law, release etch kinetics are derived for primitive geometries. The behavior of complex three-dimensional structures is described by joining the solutions of constituent primitives and applying appropriate boundary conditions.The two fitting parameters, k{sub 1} and k{sub 2}, are determined from the simplest structure and describe the more complex structures well. Experimental validation of the model is presented with data for all of the geometries and four types of sacrificial oxides.
Date: May 1, 1997
Creator: Eaton, W.P.; Jarecki, R.L. & Smith, J.H.
Partner: UNT Libraries Government Documents Department

Insensitive HE EOS

Description: A typical insensitive high explosive such as LX-17 has a large carbon-content and produces hydrogen fluoride (HF) as a detonation product. It is also characterized by slow energy release as indicated by a large curvature of the detonation front. We analyze these new physics issues which are needed to predict the performance of a insensitive high explosive. (U)
Date: December 1, 1997
Creator: Ree, F.H.; Viecelli, J. & van Thiel, M.
Partner: UNT Libraries Government Documents Department

Depleted uranium plasma reduction system study

Description: A system life-cycle cost study was conducted of a preliminary design concept for a plasma reduction process for converting depleted uranium to uranium metal and anhydrous HF. The plasma-based process is expected to offer significant economic and environmental advantages over present technology. Depleted Uranium is currently stored in the form of solid UF{sub 6}, of which approximately 575,000 metric tons is stored at three locations in the U.S. The proposed system is preconceptual in nature, but includes all necessary processing equipment and facilities to perform the process. The study has identified total processing cost of approximately $3.00/kg of UF{sub 6} processed. Based on the results of this study, the development of a laboratory-scale system (1 kg/h throughput of UF6) is warranted. Further scaling of the process to pilot scale will be determined after laboratory testing is complete.
Date: December 1, 1994
Creator: Rekemeyer, P.; Feizollahi, F.; Quapp, W.J. & Brown, B.W.
Partner: UNT Libraries Government Documents Department

The Uptake of Hydrogen Fluoride by a Forest

Description: A mathematical model of hydrogen fluoride (HF) deposition and accumulation of fluoride in a Eucalyptus rostrata forest has been developed. The model is based on tree physiology and meteorological principles. The data base for the model was derived from a literature survey of the physiological characteristics of E. rostrata and similar eucalyptus species and from current knowledge of meteorological processes in plant canopies.
Date: December 18, 1980
Creator: Murphy, C.E. Jr.
Partner: UNT Libraries Government Documents Department

Synthetic infrared spectra for correlation spectroscopy

Description: As a first step toward the development of a new remote sensing technique that the authors call holographic correlation spectroscopy, they demonstrate that diffractive optics can be used to synthesize the infrared spectra of real compounds. In particular, they have designed, fabricated, and characterized a diffractive element that successfully reproduces the major features f the spectrum of gaseous HF in the region between 3,600 cm{sup {minus}1} and 4,300 cm{sup {minus}1}. The reflection-mode diffractive optic consists of 4,096 lines, each 4.5 {micro}m wide, at 16 discrete depths relative to the substrate (from 0 to 1.2 {micro}m), and was fabricated on a silicon wafer using anisotropic reactive ion-beam etching in a four-mask-level process. The authors envision the use of diffractive elements of this type to replace the cumbersome reference cells of conventional correlation spectroscopy and thereby enable a new class of compact and versatile correlation spectrometers.
Date: December 1, 1997
Creator: Sinclair, M.B.; Butler, M.A.; Ricco, A.J.; Kravitz, S.H.; Zubrzycki, W.J. & Warren, M.E.
Partner: UNT Libraries Government Documents Department

Electrodeposition progress report, October 1--31, 1948

Description: The general points being considered in the construction of equipment for the production of High Level Postum Gauzes were mentioned in the last progress report. A more detailed discussion of the progress to date will be made here. The development work of plating postum out of hydrofluoric acid has proceeded to the point where it is desired to make some runs plating out quantities of postum from 10--250 units per gauze. The following points have been considered in a report for limited distribution.
Date: December 31, 1948
Creator: Orban, E.
Partner: UNT Libraries Government Documents Department

An Evaluation of the Sulfuric Acid-Sodium Nitrite Etch for Zircaloy-2

Description: Preliminary experiments indicate that there are no significant differences in the corrosion rates of zirconium or Zircaloy-2 after etching with the nitric--hydrofluoric solution or the sulfuric--nitrite solution, provided proper etching and washing techniques are followed. Incomplete removal of the residual etchant is deleterious to the corrosion resistance; however, this effect in the case of the sulfuric--nitrite solution is not as pronounced as in the case of the nitric--hydrofluoric acid solution. The anticipated advantages in the new etch were not completely realized. Additional development aimed at modifying the sulfuric--nitrite etch would have to be performed in order to overcome the disadvantages before recommendation for the adoption of the etch could be made. (auth)
Date: February 17, 1954
Creator: Kass, S.
Partner: UNT Libraries Government Documents Department

Effects of wet etch processing on laser-induced damage of fused silica surfaces

Description: Laser-induced damage of transparent fused silica optical components by 355 nm illumination occurs primarily at surface defects produced during the grinding and polishing processes. These defects can either be surface defects or sub-surface damage.Wet etch processing in a buffered hydrogen fluoride (HF) solution has been examined as a tool for characterizing such defects. A study was conducted to understand the effects of etch depth on the damage threshold of fused silica substrates. The study used a 355 nm, 7.5 ns, 10 Hz Nd:YAG laser to damage test fused silica optics through various wet etch processing steps. Inspection of the surface quality was performed with Nomarski microscopy and Total Internal Reflection Microscopy. The damage test data and inspection results were correlated with polishing process specifics. The results show that a wet etch exposes subsurface damage while maintaining or improving the laser damage performance. The benefits of a wet etch must be evaluated for each polishing process.
Date: December 22, 1998
Creator: Battersby, C.L.; Kozlowski, M.R. & Sheehan, L.M.
Partner: UNT Libraries Government Documents Department

Justification for Selecting Level A vs. Level B Personal Protective Equipment to Remediate a Room Containing Concentrated Acids, Bases and Radiological Constituents

Description: Selecting the appropriate personal protective equipment (PPE) is based on providing an adequate level of employee protection relative to the task-specific conditions and hazards. PPE is categorized into four ensembles, based on the degree of protection afforded; e.g., Levels A (most restrictive), B, C, and D (least restrictive). What is often overlooked in preparing an ensemble is that the PPE itself can create significant worker hazards; i.e., the greater the level of PPE, the greater the associated risks. Furthermore, there is confusion as to whether a more ''conservative approach'' should always be taken since Level B provides the same level of respiratory protection as Level A but less skin protection. This paper summarizes the Occupational Safety and Health Administration regulations addressing Level A versus Level B, and provides justification for selecting Level B over Level A without under-protecting the employee during a particular remediation scenario. The scenario consisted of an entry team performing (1) an initial entry into a room containing concentrated acids (e.g., hydrofluoric acid), bases, and radiological constituents; (2) sampling and characterizing container contents; and (3) retrieving characterized containers. The invasive nature of the hydrofluoric acid sampling and characterization scenario created a high potential for splash, immersion, and exposure to hazardous vapors, requiring additional skin protection. The hazards associated with this scenario and the chemical nature of hydrofluoric acid provided qualitative evidence to justify Level A. Once the hydrofluoric acid was removed from the room, PPE performance was evaluated against the remaining chemical inventory. If chemical breakthrough from direct contact was not expected to occur and instrument readings confirmed the absence of any hazardous vapors, additional skin protection afforded by wearing a vapor-tight, totally-encapsulated suit was not required. Therefore, PPE performance and instrument data provided quantitative evidence to justify Level B.
Date: February 25, 2002
Creator: Hylko, J. M.; Thompson, A. L.; Walter, J. F. & Deecke, T. A.
Partner: UNT Libraries Government Documents Department

Electrodeposition progress report, September 1--30, 1948

Description: Two difficulties which have been encountered in the attempts to prepare hydrofluoric acid solutions by precipitation and resolution are (1) dissolution of postum out of the solid precipitate leaving behind a solid bismuth compound and (2) the plastics used for a reaction vessel. Plastics tried have not held up under the combined effects of hydrofluoric acid, moderate heat, and alpha bombardment and the overall yield of the method is rather low. The plastics problem may be solved by the use of ``Fluorothene`` which is on order from the Atomic Energy Commission and should arrive soon. The problem of leaching the postum from the precipitate may be solved by careful control of pH during precipitation procedure to avoid the precipitation of as much bismuth as possible.
Date: December 31, 1948
Creator: Orban, E.
Partner: UNT Libraries Government Documents Department

CORROSION OF STAINLESS STEEL IN HNO$sub 3$-HF SOLUTIONS

Description: Studies were made on the safe handling of HHO/sub 3/-HF solutions in 304 L and 309SCb stainless-steel equipment under carefully controlled conditions. The corrosion behavior of both wrought and welded 304L and 309SCb was investigated in various HNO/sub 3/--HF solutions, ranging in HNO/sub 3/ concentration from 0 to 10.0 M and HF concentration from 0.01 to 1.5 M, at temperatures from 24 deg C to the boiling point. (auth)
Date: July 1, 1960
Creator: Kranzlein, P.M.
Partner: UNT Libraries Government Documents Department