Power-plant fly-ash utilization: a chemical processing perspective
The 1976 Resource Conservation and Recovery Act (RCRA) deals with the management of solid and hazardous wastes, and encourages energy and resource recovery. Recent research has indicated that solid wastes from coal combustion, including fly ash, could be classified as hazardous under present EPA definitions. The seriousness of this possibility has been recognized and new rules for coal ash waste disposal are being considered. Ames Laboratory research on fly ash utilization as an alternative to disposal includes extraction of metals from the ash and discovery of uses for the process residues. Recovery of alumina and iron oxides by physical and chemical processing would permit large scale utilization of fly ash and help reduce dependency on imports. One of the processes investigated uses a lime-soda sinter method to form soluble aluminate compounds from mixtures of fly ash, limestone, and soda ash. The aluminates are extracted, treated to remove silicates, and precipitated: the precipitate is calcined to metallurgical grade alumina. The extract residue shows promise as a raw material for the production of Portland cement. Process economics are presented, and the effects of alumina and silica contents of the fly ash, sintering temperatures and time, and sales credits for by-products are discussed.
- Research Organization:
- Ames Lab., IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6368485
- Report Number(s):
- IS-M-321; CONF-810151-1; ON: DE81025452
- Country of Publication:
- United States
- Language:
- English
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AEROSOL WASTES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ASHES
CARBONACEOUS MATERIALS
CHALCOGENIDES
COAL
DATA
ECONOMICS
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FLY ASH
FOSSIL FUELS
FUELS
HAZARDS
HEALTH HAZARDS
HYDROGEN COMPOUNDS
INFORMATION
MANAGEMENT
MATERIALS
METALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
POWER PLANTS
PRODUCTION
RECYCLING
RESIDUES
RESOURCE CONSERVATION
SAILS
WASTE DISPOSAL
WASTE MANAGEMENT
WASTE PRODUCT UTILIZATION
WASTES
WATER