Chemical and physical stability of refractories for use in coal gasification. Third annual progress report, May 1, 1978-April 30, 1979

Technical Report · Tue May 22 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5841276· OSTI ID:5841276

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

Of all the refractories examined, the cement-bonded castables showed the most chemical reaction with the test atmospheres. In most cases, the reactions consisted of the formation of boehmite (Al/sub 2/O/sub 3/.H/sub 2/O) and CaCO/sub 3/ in saturated atmospheres (below 500/sup 0/F) while only CaCO/sub 3/ formed in unsaturated atmospheres (1000/sup 0/F). The formation of boehmite, especially in the dense alumina castables, resulted in large increases (doubling or tripling) of the flexural strength. No significant differences in chemical reactivity was noted between the three commercial calcium aluminate cements examined nor between different commercial or laboratory-prepared castables. Any differences between different manufacturers of the same type of refractory is at best a second order factor affecting their performance for the conditions investigated. Other property changes, such as weight, dimension, density, and porosity, especially those of intermediate alumina and insulating castables, were small. The physical/mechanical properties of phosphate-bonded refractories showed relatively little change except for specimens exposed to saturated atmospheres where a large reduction in flexural strength occurred. This reduction in strength is attributed to chemical attack of phosphate bond phases by high pressure, saturated steam. Steam and CO/CO/sub 2/ were the only gases found to react significantly with the refractories.

• Research Organization: Missouri Univ., Rolla (USA)
• OSTI ID: 5841276
• Report Number(s): COO-2904-12
• 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
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
CHEMICAL REACTIONS
COAL GASIFICATION PLANTS
COMPARATIVE EVALUATIONS
FLEXURAL STRENGTH
INDUSTRIAL PLANTS
MATERIALS
MECHANICAL PROPERTIES
REFRACTORIES
STABILITY