OBSERVATIONS OF CHEMICAL REACTIONS IN BORON-CONTAINING GRAPHITE PELLETS IN THE DIRECT-CURRENT ARC (in German)
Journal Article
·
· Zeitschrift fuer Analytische Chemie (West Germany) Changed to Fresnius Z. Anal. Chem.
OSTI ID:4109480
Graphite pellets containing 5 wt% boron in the form of B, B/sub 2/O/sub 3/, H/sub 3/BO/sub 3/, BN, Na/sub 2/B/sub 4/O/sub 7/, CaB/sub 4 /O/sub 7/, B/sub 2/O/sub 3/ + NaCl, or B + NaF, respectively, are heated in argon-oxygen atmosphere in a d-c arc. The discharged pellets were sectioned and investigated by x-ray diffraction. The results were correlated with thermo-chemical calculations, kinetic considerations, and with the observed intensities of the boron lines. In all cases, B/sub 4/C was formed. The reaction rates were controlled by solid state diffusion. Most favorable. for B/sub 4/C formation was elementary boron. The other compounds at reaction temperature formed volatile or gaseous products, which were lost through channels and cracks and by diffusion and fractionation through the electrode walls. The B/sub 4/C formation was favored by Na and Ca compounds. An increased material transport within the excitation zone caused by the carrier effect of the gaseous products was noted. (auth)
- Research Organization:
- Kernforschungsanlage, Julich, Ger.
- NSA Number:
- NSA-18-010105
- OSTI ID:
- 4109480
- Journal Information:
- Zeitschrift fuer Analytische Chemie (West Germany) Changed to Fresnius Z. Anal. Chem., Journal Name: Zeitschrift fuer Analytische Chemie (West Germany) Changed to Fresnius Z. Anal. Chem. Vol. Vol: 198; ISSN ZANCA
- Country of Publication:
- Country unknown/Code not available
- Language:
- German
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Related Subjects
ARGON
ATMOSPHERE
BORATES
BORAX
BORON
BORON CARBIDES
BORON HYDROXIDES
BORON NITRIDES
BORON OXIDES
CALCIUM COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
CONTROL
DIFFRACTION
DIFFUSION
ELECTRIC ARCS
ELECTRIC CHARGES
ELECTRIC DISCHARGES
ELECTRODES
EXCITATION
GASES
GRAPHITE
HEATING
MEASURED VALUES
NUMERICALS
OXYGEN
PELLETS
QUALITATIVE ANALYSIS
REACTION KINETICS
SEPARATION PROCESSES
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM FLUORIDES
SOLIDS
TEMPERATURE
TRANSPORT
VOLATILITY
X RADIATION
ATMOSPHERE
BORATES
BORAX
BORON
BORON CARBIDES
BORON HYDROXIDES
BORON NITRIDES
BORON OXIDES
CALCIUM COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
CONTROL
DIFFRACTION
DIFFUSION
ELECTRIC ARCS
ELECTRIC CHARGES
ELECTRIC DISCHARGES
ELECTRODES
EXCITATION
GASES
GRAPHITE
HEATING
MEASURED VALUES
NUMERICALS
OXYGEN
PELLETS
QUALITATIVE ANALYSIS
REACTION KINETICS
SEPARATION PROCESSES
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM FLUORIDES
SOLIDS
TEMPERATURE
TRANSPORT
VOLATILITY
X RADIATION