High temperature alkali corrosion of ceramics in coal gas

Technical Report · Mon Feb 24 00:00:00 EST 1992

DOI:https://doi.org/10.2172/6631793· OSTI ID:6631793

Pickrell, G R; Sun, T; Brown, J J

The high temperature alkali corrosion kinetics of SiC have been systematically investigated from 950 to 1100[degrees]C at 0.63 vol % alkali vapor concentration. The corrosion rate in the presence of alkaliis approximately 10[sup 4] to 10[sup 5] times faster than the oxidation rate of SiC in air. The activation energy associated with the alkali corrosion is 406 kJ/mol, indicating a highly temperature-dependent reaction rate. The rate-controlling step of the overall reaction is likely to be the dissolution of silica in the sodium silicate liquid, based on the oxygen diffusivity data.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Center for Advanced Ceramic Materials
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-91PC91309; FG22-92PC92547
• OSTI ID: 6631793
• Report Number(s): DOE/PC/91309-T7; ON: DE93011634
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALI METAL COMPOUNDS
CORROSIVE EFFECTS
CERAMICS
CORROSION
SILICON CARBIDES
ACTIVATION ENERGY
ARRHENIUS EQUATION
MOLTEN SALTS
OXIDATION
PROGRESS REPORT
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
DOCUMENT TYPES
ENERGY
EQUATIONS
SALTS
SILICON COMPOUNDS
360205* - Ceramics
Cermets
& Refractories- Corrosion & Erosion