Chemistry of the Calsinter process for aluminum recovery from fly ash
In 1977, 48.5 million tons of fly ash was produced in the United States from coal combustion. Based on an estimated average of 11.5% aluminum content in fly ash, this represent 5.58 million tons of aluminum. Similarly, for titanium, a fly ash content of 0.89% corresponds to 0.432 million tons of titanium. Both the Al and Ti quantities in flyash are close to US demand. One method for Al recovery from fly ash, the Calsinter method, is discussed. In this method fly ash is blended with gypsum and limestone. The mixture is pelletized and sintered at 1000 to 1250/sup 0/C. The sinter cake is ground and leached with dilute sulfuric acid. Waste solids are removed by filtration, and metal values are recovered from the filtrate. Aluminum can be recovered from the leach liquor by crystallization as ammonium alum or aluminum sulfate. Other metal values can be recovered by solvent extraction. Flue gas scrubber sludge, resulting from the limestone scrubbing of SO/sub 2/ from flue gas, contains calcium sulfate, calcium sulfite and unreacted calcium carbonate, and can be used instead of the gypsum and limestone. Thus, the Calsinter process becomes more attractive by combining two waste products to recover valuable resources. The characterization of fly ash and the Calsinter process material, and the effects of sintering temperature, composition, sintering time, and leach rate on the aluminum recovery are described.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5510835
- Report Number(s):
- CONF-800205-3(Draft)
- Resource Relation:
- Conference: American Institute of Metallurgical Engineers meeting, Las Vegas, NV, USA, Feb 1980
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM
MATERIALS RECOVERY
FLY ASH
CHEMICAL COMPOSITION
RECYCLING
TITANIUM
COAL
COMBUSTION
EXPERIMENTAL DATA
FOSSIL-FUEL POWER PLANTS
GRAPHS
INDUSTRIAL PLANTS
LEACHING
SCRUBBERS
SINTERING
SLUDGES
TABLES
WASTE PROCESSING
AEROSOL WASTES
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DATA
DATA FORMS
DISSOLUTION
ELEMENTS
ENERGY SOURCES
EQUIPMENT
FABRICATION
FOSSIL FUELS
FUELS
INFORMATION
MANAGEMENT
METALS
NUMERICAL DATA
OXIDATION
POLLUTION CONTROL EQUIPMENT
POWER PLANTS
PROCESSING
RECOVERY
SEPARATION PROCESSES
THERMAL POWER PLANTS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTES
320305* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Industrial Waste Management