Dry, calcium based FGD by-products for use as stabilization/solidification agents
- Dravo Lime Co. Research Center, Pittsburgh, PA (United States)
- Ohio State Univ., Columbus, OH (United States). Dept. of Agronomy
- Ohio State Univ., Columbus, OH (United States). Dept. of Engineering
In dry flue gas desulfurization (FGD) systems the sorbent (usually slaked lime, limestone or dolomite) is injected directly into the furnace, into the ductwork after the furnace at lower temperature, or into a spray dryer vessel. All these processes produce a dry by-product which is removed in the particulate control equipment, as opposed to wet scrubber systems in which the by-product is a slurry collected separately from the fly ash. Dry FGD scrubber by-products from lime or Iimestone injected directly into the furnace such as fluid bed combustion (FBC) and LIMB (lime injected multistage burners) systems, have neutralization, sorption, and cementation properties that make them potential reagents for hazardous and non-hazardous waste stabilization because the dry sorbent by-products have high free quicklime (CaO) contents and anhydrous calcium sulfate (CaSO{sub 4}) contents. Four solidification reactions can take place, including hydration, carbonation, pozzolanic activity and ettringite formation. Other lime injection scrubber by-products such as from duct injection or spray dryer processes may not be as effective for solidification because the free lime and calcium sulfite and sulfate are hydrated due to humidification of the gas stream. Chemical and physical properties of dry by-products from a number of sources for use as stabilization reagents are discussed as well as the reasons for differences among various processes. Comparisons will be made with other by-products, including class C and class F coal fly ash, cement kiln dust and lime kiln dust. Five clean coal technologies using high sulfur coal reacted with lime or limestone had TCLP leachate concentrations of the 8 RCRA toxic metal elements that were low and very close to USEPA drinking water standards. Success stories involving the use of these materials for stabilization of toxic metals and some oily wastes have been reported and further suggestions are made for beneficial re-use.
- Research Organization:
- Dravo Lime Co., Pittsburgh, PA (United States). Research Center
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC21-91MC28060
- OSTI ID:
- 10118965
- Report Number(s):
- DOE/MC/28060-94/C0275; CONF-931119-3; ON: DE94006005; TRN: 94:001981
- Resource Relation:
- Conference: 3. international symposium on stabilization/solidification of hazardous, radioactive and mixed wastes,Williamsburg, VA (United States),1-5 Nov 1993; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
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