Geochemistry of FBC waste-coal slurry solid mixtures. Final technical report, September 1, 1992--August 31, 1993
- Illinois State Geological Survey, Champaign, IL (United States)
The three tasks conducted in this research project were related to understanding the geochemistry and mineralogy of the co-disposal of fluidized bed combustion (FBC) wastes with coal slurry solid (CSS) from a coal preparation plant. During coal cleaning, pyrite, other heavy minerals and rock fragments are separated from the coal and discharged in an aqueous slurry to an impoundment. After dewatering and closure of the impoundment, the pyrite can oxidize and produce acid that can migrate into the underlying groundwater system. The addition of FBC residue to the CSS will buffer the pore water pH to approximately 7.8. In Task 1, soluble components and acid-base react ion products from mixtures of FBC waste and CSS were extracted for 3 to 180 days in aqueous batch experiments. The results of these extractions showed that, eventually, the extracts would attain a pH between 7 and 8. That pH range is characteristic of an aqueous system in equilibrium with calcite, gypsum, and atmospheric carbon dioxide. After 180 days, the mean calcium concentration in all of the extracts was 566{+-}18 mg/L and sulfate concentrations averaged 2420{+-}70 mg/L. In Task 2, three extracts from CSS/FBC residue mixtures were prepared for use in experiments to determine the adsorption/desorption reactions that occur between solutes in the extracts and two common Illinois soils. Time constraints allowed the use of only two of the extracts for adsorption studies. The concentrations of most solutes were not significantly lowered by adsorption at the pH of the extract-soil suspension, nor over a wide range of pH. The results suggest that the type of solutes that were released by the CSS/FBC residue mixture would not be attenuated by adsorption. In a modified Task 3, the literature on the kinetics of pyrite oxidation in near-neutral to alkaline pH was reviewed in preparation for future development of a computer model of pyrite oxidation in CSS/FBC residue codisposal.
- Research Organization:
- Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC22-92PC92521
- OSTI ID:
- 10132203
- Report Number(s):
- DOE/PC/92521-T74; ON: DE94008016; TRN: 94:003529
- Resource Relation:
- Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
54 ENVIRONMENTAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
SLURRIES
GEOCHEMISTRY
MINERALOGY
POLLUTION CONTROL
PYRITE
OXIDATION
COAL
WASTE DISPOSAL
PROGRESS REPORT
FLUIDIZED-BED COMBUSTION
GROUND WATER
PH VALUE
COMPUTERIZED SIMULATION
SOILS
010800
540220
400201
010900
WASTE MANAGEMENT
CHEMICALS MONITORING AND TRANSPORT
CHEMICAL AND PHYSICOCHEMICAL PROPERTIES
ENVIRONMENTAL ASPECTS