Electrode cokes from deashed bituminous coal (in German)
This scheme for producing electrode cokes required a final ash content less than 0.4%. To achieve this goal, flotation of the coal was performed three times to physically remove the ash, before a chemical method was employed. The flotation processes reduced the ash content to 0.8% to 0.9% for bituminous coal from the mining company ''Auguste-Viktoria''. For chemical deashing, 2.8% NaOH was reacted with the coal for 8 minutes at 250/sup 0/ to 260/sup 0/C. The coal-lye suspension was then centrifuged to recover the lye, washed with 5% HCl at 60/sup 0/ to 70/sup 0/C, then water washed, dried, and coked. The chemically deashed coal retained 0.25% to 0.28% ash and the coke contained 0.35% to 0.38% ash. Increasing the NaOH concentration or the reaction time had little influence over the ash content. By using temperatures greater than 260/sup 0/C in the lye deashing, ash content increased, probably due to the incorporation of Na/sub 2/O. For the Auguste-Viktoria coal, it was found that 260/sup 0/C was the most favorable chemical deashing temperature yielding the lowest possible ash content, while retaining the coking properties of the coal as well as rendering a coke with good density, conductivity, and reactivity. This process was also adapable to other coals such as anthracite and sub-bituminous coals, where the main prerequisite was a sufficient degree of preliminary deashing. The density and specific resistance of the cokes were realted to the temperature of the coking oven and it was found that with an oven wall temperature of 1150/sup 0/C (corresponding to a circulating gas temperature of 1250/sup 0/C), good density and conductivity were obtained. The structures of the cokes were favorably enhanced by combining 30% of a coal extract or 20% hard pitch to form mixed cokes. 4 tables, 1 graph
- Research Organization:
- Corporate Unverified
- OSTI ID:
- 6743900
- Report Number(s):
- TOM-286-96-104
- Country of Publication:
- United States
- Language:
- German
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Production of electrode cokes by chemical deashing of bituminous coal
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010401 -- Coal & Coal Products-- Carbonization-- (-1987)
010600 -- Coal
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& Peat-- Properties & Composition
013000* -- Coal
Lignite
& Peat-- Transport
Handling
& Storage
ALKALI METAL COMPOUNDS
ASHES
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CARBONIZATION
CENTRIFUGATION
CHALCOGENIDES
CHEMICAL REACTIONS
COAL
COKE
COKING
COMPARATIVE EVALUATIONS
DATA COMPILATION
DEASHING
DECOMPOSITION
DIAGRAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRODES
ENERGY SOURCES
EQUIPMENT
FLOTATION
FOSSIL FUELS
FUELS
HIGH TEMPERATURE
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
INORGANIC ACIDS
MEDIUM PRESSURE
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PITCHES
PRODUCTION
QUANTITY RATIO
REMOVAL
RESIDUES
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SODIUM OXIDES
TABLES
YIELDS