Coal fly ash: a review of the literature and proposed classification system with emphasis on environental impacts
This comprehensive review of the scientific literature on fly ash generated by coal burning power plants cites studies reported in 284 publications up to September 1980. General conclusions are formulated, on the basis of data compiled from this review, on the physico-chemical characteristics of the solid waste and the possible environmental impacts of its disposal. Fly ash is composed of fine-grained particles that have a variable morphology and consist primarily of an amorphous glassy material. The elemental composition of fly ash is highly variable and directly related to compositional variations in the parent coals and to the operational characteristics of the individual power plants. Some elements are concentrated (enriched) on fly ash particle surfaces. While the glass-like particles are essentially insoluble in water, the enriched surface elements may be soluble and therefore available to the environment upon leaching of the solid waste. Fly ash leachates also demonstrate a great deal of variability in chemical composition. Toxicity studies suggest that fly ash leachates may adversely effect aquatic ecosystems, while the solid material may be hazardous to terrestrial ecosystems by direct external reactions (skin, eyes, etc.) or reactions in the respiratory tract or alimentary canal. The predominant method of fly ash disposal is by wet sluicing to on-site ash ponds. The greatest use of the solid waste is as an additive to concrete mixture; several other schemes for using the solid waste have been proposed. Plants grown experimental fly ash amended soils have shown enrichment of certain chemical constituents in plant tissues. A classification system for fly ash is proposed in this paper; this system should aid in systematic fly ash research and in the discussion of fly ash properties.
- Research Organization:
- Illinois State Geological Survey, Urbana (USA)
- OSTI ID:
- 6444034
- Report Number(s):
- EGN-96
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010600 -- Coal
Lignite
& Peat-- Properties & Composition
010800* -- Coal
Lignite
& Peat-- Waste Management
AEROSOL WASTES
ASHES
CHEMICAL COMPOSITION
CHEMICAL PROPERTIES
CLASSIFICATION
DISPERSIONS
DOCUMENT TYPES
ENVIRONMENTAL IMPACTS
FLY ASH
FOSSIL-FUEL POWER PLANTS
LEACHATES
MANAGEMENT
MIXTURES
PHYSICAL PROPERTIES
POWER PLANTS
RESIDUES
REVIEWS
SOLUTIONS
THERMAL POWER PLANTS
TOXICITY
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES