Effects of alternate fuels refractory test facility test 3. Part 2. Analysis of magnesia- and alumina-based dense refractories exposed to the combustion products of No. 6 residual oil

Technical Report · Tue Jul 01 04:00:00 EDT 1980

OSTI ID:5381980

Federer, J I; Tennery, V J

Industrial conversion from natural gas to residual oil or coal for process heating generally accelerates deterioration of refractories because of reactions with fuel impurities. This investigation was the third experiment to determine the nature and extent of degradation reactions between fuel impurities (in combustion products) and constituents of the refractories under controlled combustion conditions. The dense refractories included three magnesia-based bricks, a chrome mortar, three alumina-based bricks, and three alumina-based castables. These specimens were exposed to the combustion products of a medium-sulfur No. 6 oil at a hot-face temperature of 1350/sup 0/C for 1002 h with 7 to 10% excess oxgyen. The furnace was cycled 18 times between 500 and 1350/sup 0/C. The specimens were analyzed by ceramography, electron microprobe analysis, and x-ray diffraction. Some specimens contained cracks originating at the hot face. The magnesia-based bricks evidently contained a network of small cracks, since they fragmented easily. Cracking was caused by excessive cooling rates from 1350/sup 0/C when equipment failure caused unscheduled furnace shutdowns. All the specimens were discolored. The depth of the colored zone from the hot face increased with decreasing alumina content in the alumina-based refractories. Fuel impurities were detected on the hot faces and in some specimens in various phases near the hot face; however, new phases involving fuel impurities were definately identified only in two alumina-based bricks. We concluded that no significant degradation of the refractorie due to impurity-related phase formation occurred under the conditions of this test because the oil contained relatively low concentrations of impurities. This fuel, therefore, was not very agressive in degrading the refractory specimens.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5381980
• Report Number(s): ORNL/TM-7284
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
36 MATERIALS SCIENCE
360200 -- Ceramics
Cermets
& Refractories
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION PRODUCTS
DATA
DECOMPOSITION
EXPERIMENTAL DATA
FUEL OILS
FUEL SUBSTITUTION
FUELS
FURNACES
IMPURITIES
INDUSTRIAL PLANTS
INFORMATION
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MATERIALS TESTING
NUMERICAL DATA
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PETROLEUM PRODUCTS
REFRACTORIES
RESIDUAL FUELS
TESTING
THERMAL DEGRADATION
THERMOCHEMICAL PROCESSES