Chemical and physical stability of refractories for use in coal gasification. Second annual progress report, May 1, 1977--April 30, 1978

Technical Report · Mon May 22 04:00:00 EDT 1978

DOI:https://doi.org/10.2172/6502837· OSTI ID:6502837

Rahman, S. F.; Day, D. E.

With the exception of the weight and porosity changes for the cement bonded castables immersed in water during exposure, the properties of the various refractories after long-term (60-days) exposure in the unsaturated and saturated DOE atmospheres were similar to those observed in 10 to 30 days DOE or CO-Steam atmospheres. The major changes in properties occur within relatively short times, a few days, and depend more upon the degree of saturation of the atmosphere than upon exposure time. Except for the CO/H/sub 2/O = 3.0 atmosphere, all the cement-bonded castables showed higher strengths in saturated than in non-saturated atmospheres. Depending upon the CO/H/sub 2/O ratio, the liquid conditions were generally more reactive then the vapor. With increasing CO content of the atmosphere, the rate of dissolution of CaO increases, particularly for samples immersed in water. In the high alumina castables containing pure calcium aluminate cement, UMR-1 and 2, the strength tends to decrease with increasing CO/H/sub 2/O ratio. Other castables containing silica tend not to show as large a dependence of strength upon CO/H/sub 2/O ratio. No reaction has been observed between the various refractory aggregates and the gases in the DOE atmosphere (including steam), either saturated or non-saturated. In unsaturated atmospheres only calcite is formed. Both calcite and boehmite form in all of the cement-bonded high and intermediate alumina and insulating castables exposed to saturated atmospheres. In saturated atmospheres CaO is leached from the refractories, particularly those in contact with liquid, by a process highly dependent upon the CO/H/sub 2/O ratio.

• Research Organization: Missouri Univ., Rolla (USA). Dept. of Ceramic Engineering
• OSTI ID: 6502837
• Report Number(s): COO-2904-8
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
36 MATERIALS SCIENCE
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ALKALINE EARTH METAL COMPOUNDS
ALUMINATES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ATMOSPHERES
BINDERS
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COAL GASIFICATION PLANTS
COMPARATIVE EVALUATIONS
CONTROLLED ATMOSPHERES
CORROSION
CORROSION RESISTANCE
DENSITY
FLEXURAL STRENGTH
INDUSTRIAL PLANTS
MATERIALS TESTING
MECHANICAL PROPERTIES
NONDESTRUCTIVE ANALYSIS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POROSITY
REFRACTORIES
STEAM
TESTING
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS