Volume 8, Issue 5 (September 1980)
Utilization of Fluidized Bed Combustion Wastes
Atmospheric fluidized bed (AFB) combustion appears to be a promising means for producing energy from high sulfur coal in an environmentally acceptable manner. The process involves burning crushed coal in a bed of limestone or dolomite that has been fluidized by jets of hot air. The resultant by-products are a dry, sand-size spent bed residue and a relatively high carbon fly ash. This discussion focuses on possible uses for this material, the spent bed residue. The paper is a progress report for a research program sponsored by the U.S. Department of Energy to evaluate potential commercial applications for fluidized bed combustion wastes. Included in the paper are laboratory data related to seven separate residue sources; a discussion of promising approaches to beneficiation; and supporting data on several potential applications involving the use of the relatively high calcium content of the material as a lime substitute or in the form of a cementitious structural product. Specific applications include stabilized road base compositions, masonry block, artificial reefs, partial replacement for portland cement, synthetic aggregate, flue gas desulfurization, neutralization of acid mine drainage, and treatment of industrial trade wastes. Also briefly discussed are efforts to evaluate the environmental impact of AFB waste disposal.