Solid by-products of coal combustion: Fly ash as a source of industrial minerals

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:549536

Bhagwat, S B; Rapp, D M ^[1]; Bukowski, J M ^[2]

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1. Illinois State Geological Survey, Champaign, IL (United States)
2. Univ. of Illinois, Urbana, IL (United States). Dept. of Material Science

Fly ash is one of the most important by-products of coal combustion. It is a complex mix of cenospheres, reactive glasses, magnetite and carbon, in addition to minor quantities of other minerals. Fly ash components are determined by the type of coal, the combustion technology, material collection system and the temperature of combustion. The changing mix of coal burned in power plants is increasingly making the fly ash characteristics independent of the locally mined coal. Fly ash is thus becoming a raw material independent of the existence of a local coal mining industry. Currently, about 65 million tons of fly ash are generated annually in the United States. This is equivalent to the crushed stone production of such highly industrialized states as Illinois. Only about twenty percent of the total fly ash are currently used, mostly in low value applications such as road building materials and concrete additions. The fly ash currently represents an environmental and financial liability to electric utilities. The increasingly competitive and boundaryless electricity market in the US increases the incentive to look at fly ash in terms of its individual components and recognize their potential as industrial minerals in the production of value added materials. For example, zeolites and other adsorbents could be produced from reactive glasses, magnetite could be used in pigments and ferrite manufacture, activated carbon could serve in pollution control and cenospheres could be used to make lightweight ceramics. If one begins to look at fly ash as a source of industrial minerals and not as a waste product, this change in perspective could turn a financial and environmental liability into an economic opportunity.

• OSTI ID: 549536
• Report Number(s): CONF-960954--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
CARBON
FLY ASH
GLASS
INDUSTRY
MAGNETITE
MATERIALS RECOVERY
MICROSPHERES
RAW MATERIALS
RESOURCE ASSESSMENT
USES