PART I. FLUOROCARBON FLAMES. PART II. DISSOLUTION OF URANIUM IN NITRIC ACID

Journal Article · Sun Apr 01 04:00:00 EST 1962 · Dissertation Abstr.

OSTI ID:4830417

Salzman, J D

< The phenomenon of fluorocarbon flames was investigated by: (1) attempting to produce flames by the reaction of several fluorocarbons with oxygen, chlorine, nitrogen dioxide, nitric oxide, and various mixtures of these gases in a flow system, and (2) obtaining thc spectra of the flames thus produced. The fluorocarbons investigated were chlorotrifluoroethylene, 1, 1- difluoroethylene, 1,2-dichloro1,2-difluoroethylene, perfluorocyclobutene, and perfluoroisobutene. All of these compounds react with oxygen to produce luminous diffusion flames, the most intense of which is produced by 1,1-difluoroethylene. The luminosity of the flames resulting from the reaction of chlorotrifluoroethylene with oxygen is decreased by premixing nitric oxide with the fuel. In addition to producing a luminous diffusion flame, chlorotrifluoroethylene also reacts with oxygen to produce a faint, blue glow which is immediately extinguished by the presence of small amounts of nitric oxide or nitrogen dioxide. However, if chlorine is also present, small amounts of these oxides cause the glow to lapse into a series of bright flashes. On the other hand, a steady, luminous diffusion flame can be produced by the reaction of chlorotrifluoroethylene with pure nitrogen dioxide. The reaction is accompanied by the decomposition of nitrogen dioxide and the formation of soot. With most of the flames investigated, the presence of chlorine tends to increase luminosity and soot formation. The spectra of the luminous flames show thermal continua. The spectra of the chlorotrifluoroethylene flames investigated indicate the presence of a continuum which appears to be very similar to that which has been attributed to the reaction: 2C1 yields Cl2/sub 2/. Discrete emission was observed only in the spectra of the flame produced by the reaction of 1,1- difluoroethylene with oxygen and of the flames produced by the reaction of chlorotrifluoroethylene with the oxides of nitrogen. In the spectrum of the former appeared bands due to C/sub 2/, CH, and OH and lines due to Na and Si; bands due to CN appeared in the spectra of the latter flames. Part II. Various factors which influence the rate of dissolution of uranium in nitric acid were investigated by dissolving samples of the metal from ten different lots of varying analysis and metallurgical treatment under various conditions of temperature, acid concentration, and concentration of the products of the reaction. The samples which dissolved most rapidly were those with relatively high carbon and nitrogen contents. This effect appears to be augmented by the amount of metallurgical treatment that the sample has received, i.e., samples with high carbon and nitrogen analyses dissolved even more rapidly as the amount of work'' which the sample had received was increased; however, the amount of work received did not influence the rate of dissolution of samples with relatively low carbon and nitrogen contents. The effect of metallurgical treatment on the rate of dissolution is probably due to the resulting grain size of the metal, which decreases as the amount of work received is increased. Samples of metal which had been worked dissolved more rapidly along the axis of the rod from which they had been cut than in other directions. The rate of dissolution of uranium in nitric acid increases as the reaction proceeds. This effect can be prevented to some- extent by increasing the rate of stirring or by the addition of urea; the rate can be further increased by addition of potassium nitrite. The increase in the rate of dissolution as the reaction proceeds is attributed to the increase in concentration of nitrous acid which is formed during the reaction and also to the increase in surface area of the metal. In nitric acid uranium behaves like a metal below hydrogen in the electromotive series. The rate of the reaction is strongly dependent on acid concentration, and the metal becomes passive in dilute acid. The maximum rate of dissolution occurs at concentrations of 13 to 14 N. The temperature

• Research Organization: Univ. of Colorado, Boulder
• NSA Number: NSA-16-023536
• OSTI ID: 4830417
• Journal Information: Dissertation Abstr., Journal Name: Dissertation Abstr. Vol. Vol: 22
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDITY
ADSORPTION
BUTYLENE
CARBON
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE
COLOR
COMBUSTION
CONCENTRATION
CONFIGURATION
CYCLOALKANES
DECOMPOSITION
ELECTRIC POTENTIAL
ETHYL RADICALS
ETHYLENE
FLAMES
GAS FLOW
GRAIN SIZE
ISOBUTYLENE
LIGHT
METALLURGY
MINERAL ACIDS
MIXING
NITRIC ACID
NITRITES
NITROGEN
NITROGEN OXIDES
NITROUS ACID
ORGANIC CHLORINE COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
OXYGEN
POTASSIUM COMPOUNDS
QUALITATIVE ANALYSIS
QUANTITY RATIO
REACTION KINETICS
RODS
SAMPLING
SILICON
SODIUM
SOLUTIONS
SPECTRA
SPECTROSCOPY
SURFACE AREA
SURFACES
TEMPERATURE
TESTING
TURBULENCE
URANIUM
UREA
VELOCITY