Coal cleaning waste as an additive in the lime-sinter process for the recovery of alumina from power plant fly ash
The addition of a small amount of coal cleaning waste to lime-fly ash mixtures increases the alumina recovery to over 90%. Experiments were run with sinter mixtures containing bituminous and subbituminous fly ashes and varying amounts of lime and coal cleaning waste. The various mixtures were sintered between 1000/sup 0/C and 1350/sup 0/C for 0.5 to 1 hours. Alumina recovery and qualitative and quantitative x-ray diffraction analysis were obtained for each sample. Alumina compounds that have been identified in the sintered mixtures are: calcium alumina ferrite (C/sub 4/AF), calcium aluminate (C/sub 12/A/sub 7/), calcium sulfoaluminate (C/sub 4/A/sub 3/S), and gehlenite (C/sub 2/AS). The C/sub 4/AF and C/sub 2/AS compounds are insoluble aluminates and remained in the filtrate. The C/sub 4/A/sub 3/S and C/sub 12/A/sub 7/ are the soluble aluminate that form and account for 90 to 95% of the recovered alumina. Other calcium aluminates such as: CA or C/sub 3/A may form during sintering, but not in large enough quantities (less than 1 wt %) to be observed from the x-ray patterns obtained.
- Research Organization:
- Ames Lab., IA (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 6867632
- Report Number(s):
- IS-T-1128; ON: DE84014103
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Thesis. Submitted to Iowa State Univ., Ames
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM
MATERIALS RECOVERY
LIME-SODA SINTER PROCESS
ADDITIVES
BITUMINOUS COAL
CALCIUM OXIDES
FLY ASH
FOSSIL-FUEL POWER PLANTS
SUBBITUMINOUS COAL
AEROSOL WASTES
ALKALINE EARTH METAL COMPOUNDS
ASHES
BLACK COAL
CALCIUM COMPOUNDS
CARBONACEOUS MATERIALS
CHALCOGENIDES
COAL
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
MANAGEMENT
MATERIALS
METALS
OXIDES
OXYGEN COMPOUNDS
POWER PLANTS
PROCESSING
RECOVERY
RESIDUES
THERMAL POWER PLANTS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
010800* - Coal
Lignite
& Peat- Waste Management