Production of electrode cokes by chemical deashing of bituminous coal (in German)
It had been found that sedimentation and flotation deashing processes as well as chemical deashing had been able to reduce the ash content of coal to 0.2% to 0.3%. The chemical process, while removing ash, also destroyed some of the bituminous constituents, decreasing the ability of the coal to be coked. Under certain conditions, it was found that a final ash content of 0.4% to 0.5% could be obtained for the coal without significantly reducing the bitumens. For this procedure, an average cross-section of Ruhr-coal was pre-deashed by physical means to 0.8% to 1.2% ash content. The yield for the pre-deashing was about 60% of the original, with the remaining ash-rich 40% recovered to be used for heating. The deashed coal was then added to hot 20% NaOH in a 1:1 ratio and ground in a tube mill to an average of 0.2 mm. This mixture was transferred to a stirred tank reactor and kept at 80/sup 0/ to 90/sup 0/C for approximately 2 hours. The mixture was then centrifuged, washed and centrifuged again, to a 0.6% NaOH concentration. The centrifuge cake was mixed with excess water and a corresponding amount of HCl. The acid wash was decanted from a concentrator apparatus before centrifugation. There remained 0.02% NaCl which could be removed by a second decantation (with water). The refined cokes produced by this process had a low porosity, high conductivity, low ash content (.55%), and a true density of 1.88 g/cu. cm. While some cokes were objectionable due to their hardness and large yield of fines upon grinding, the chemical deashing procedure could have been strengthened to decrease hardness of the coke to improve its grindability. Included in the article was a complete cost analysis of equipment, materials, buildings, and labor for 50,000 tons/yr. 1 flowchart
- Research Organization:
- I.G. Farbenindustrie, A.G., Hoechstadt (Germany)
- OSTI ID:
- 6749418
- Report Number(s):
- TOM-286-105-112
- Country of Publication:
- United States
- Language:
- German
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Report over the present status of the work for the production of electrode cokes from bituminous coal
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ALKALI METAL COMPOUNDS
ASHES
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CARBONIZATION
CENTRIFUGATION
CHEMICAL REACTIONS
COAL
COKE
COKING
COMMINUTION
COMPARATIVE EVALUATIONS
COST
DEASHING
DECOMPOSITION
DIAGRAMS
ECONOMIC ANALYSIS
ECONOMICS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRODES
ENERGY DEMAND
ENERGY SOURCES
EQUIPMENT
FEASIBILITY STUDIES
FLOTATION
FOSSIL FUELS
FUELS
GRINDING
HIGH TEMPERATURE
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
HYDROXIDES
INORGANIC ACIDS
MACHINING
MEDIUM PRESSURE
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PITCHES
PRODUCTION
QUANTITY RATIO
RECYCLING
REMOVAL
RESIDUES
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
YIELDS