Advanced research and technology: direct utilization - recovery of minerals from coal fly ash. Technical progress report, 1 January 1981-31 March 1981. [Hi chlor and sintering processes]

Technical Report · Fri May 01 04:00:00 EDT 1981

OSTI ID:6528361

Burnet, G; Dunker, J W; Murtha, M J

The purpose of this research is to develop methods to process fly ash for 1) the separation and use of an iron-rich fraction, 2) the recovery of metals (primarily Al and Ti), and 3) use of the process residues. Research on the HiChlor process for the high-temperature chlorination of a fly ash-reductant mixture included investigation of prechlorinations at reduced temperatures to selectively remove iron and titanium, the measurement of gas diffusion rates in delta-alumina pellets, and the consideration of fused salt processes as an alternative to gas-solids reaction. A current cost estimate for the HiChlor process indicates discounted cash flow rates of return for the process of from 6.5 to 43.4 percent. Experiments on the high temperature sintering of limestone-fly ash mixtures include data collected for alumina extractions from sinters prepared using waste materials. High alumina recoveries were obtained from sinters prepared with cement kiln dust, as the lime source, and small amounts of coal refuse. X-ray diffraction measurements were used to identify the soluble and insoluble compounds in several types of sinters. The investigations of the chemical beneficiation of magnetic fly ash to remove alumina and silica indicate that a combination process of a caustic leach and an acid wash will be required for economic processing. The gangue can be extracted by a high temperature caustic process, but the processing conditions and the low solution solubilities due to common ion effects indicate that the equipment and energy requirements will be costly. The use of a combination of caustic leach and acid wash of the magnetic ash residue is effective because the gangue material is dissolved in a caustic solution, then precipitates and is redissolved in a weak acid solution. High-iron content beneficiated magnetic fly ash residues are produced.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6528361
• Report Number(s): IS-4771; ON: DE81023613
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320305 -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Industrial Waste Management
AEROSOL WASTES
ALUMINATES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ASHES
CARBON
CARBONATE ROCKS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINATION
COAL PREPARATION
COMMINUTION
DATA
ECONOMICS
ELEMENTS
EXPERIMENTAL DATA
FABRICATION
FLY ASH
FOSSIL-FUEL POWER PLANTS
HALOGENATION
HEAVY MEDIA SEPARATION
INFORMATION
IRON COMPOUNDS
IRON ORES
IRON OXIDES
LIMESTONE
MANAGEMENT
MATERIALS RECOVERY
MINERAL WASTES
NONMETALS
NUMERICAL DATA
ORES
OXIDES
OXYGEN COMPOUNDS
POWER PLANTS
PROCESSING
RECOVERY
RESIDUES
ROCKS
SEDIMENTARY ROCKS
SEPARATION PROCESSES
SINTERING
SOLID WASTES
SULFUR
THERMAL POWER PLANTS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
USES
WASTE MANAGEMENT
WASTE PROCESSING
WASTE PRODUCT UTILIZATION
WASTES