Steam-induced volatilization of silica from refractories. Rept. of Investigations/1986

Technical Report · Wed Jan 01 00:00:00 EST 1986

OSTI ID:6511938

Sadler, L Y; Davis, E G

The Bureau of Mines conducted a study to determine the loss in weight of silica (SiO/sub 2/) volatilization from low-alumina Al/sub 2/O/sub 3/ refractories used as hot face liner materials in such process equipment as coal gasifiers, synthesis gas transfer lines, and ammonia plant secondary reformers. Small specimens of 80- and 40-pct-Al/sub 2/O/sub 3/ brick and 95-pct-SiO/sub 2/ brick were exposed to steam in high-pressure furnaces at pressures of up to 1000 psig and temperatures up to 1400/sup 0/C for periods ranging up to 120 h. Weight losses from the 40-pct-A1/sub 2/O3 brick after 40 h of exposure were highest, 2.75% at 1400/sup 0/C and 1,00 psig. The rate of weight loss had dropped to near zero after 80 h of exposure at all temperatures. No relationship between total silica content of the specimen and weight loss could be established, nor did scanning electron microscopic examination of the specimens before and after exposure identify specific regions (e.g., surface) suffering a disproportionate share of the silica loss. It was concluded that minor silica volatilization is likely to occur, if at all, at temperatures of less than 1000/sup 0/C and pressures below 1000 psig, and that low-alumina refractories should be used as dry-ash coal gasifier hot-face linings.

• Research Organization: Bureau of Mines, Tuscaloosa, AL (USA). Tuscaloosa Research Center
• OSTI ID: 6511938
• Report Number(s): PB-87-167425/XAB; BM-RI-9052
• Resource Relation: Other Information: Library of Congress catalog card no. 86-600218
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
01 COAL, LIGNITE, AND PEAT
COAL GASIFICATION
LINERS
REFRACTORIES
SILICA
EVAPORATION
FURNACES
STEAM
VAPOR PRESSURE
CHALCOGENIDES
GASIFICATION
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
SILICON COMPOUNDS
SILICON OXIDES
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
360204* - Ceramics
Cermets
& Refractories- Physical Properties
010404 - Coal
Lignite
& Peat- Gasification