Report over the present status of the work for the production of electrode cokes from bituminous coal

Technical Report · Mon Apr 28 04:00:00 EDT 1941

OSTI ID:6710550

Winnacker,

For this research two types of bituminous coal were used: coal I was fine-ground and had 4.7% ash and 20.5% volatiles, coal II was coarse-ground and had 7.6% ash and 18.7% volatiles. Physical separation reduced the ash content to 1.2% for the coal I by a heavy-sink process in a calcium chloride solution with a specific gravity of 1.35. The coal II was reduced to 0.75%. To obtain electrode coke with no more than 0.6% ash, the coal had to be chemically deashed to about 0.3% ash. For the chemical deashing process, HCl, NaOH, HCl with HNO/sub 3/, H/sub 2/SO/sub 4/, and HF were all tried, but only HF and NaOH gave significant deashing results, yielding an ash content of 0.2%. Five percent HF was used cold and 20% NaOH was used at 90/sup 0/C, with approximately equal results. Both chemicals damaged coal I somewhat, but more intensive chemical treatment of coal I yielded a completely sandy, non-baking coke. Coal II was not seriously damaged by the treatment. NaOH was used in the ratio of 1390 Kg (of 20% NaOH) per 1390 Kg coal (10% moisture) and ground in a ball mill where only 10% remained on a 4900 mesh sieve. The suspension was passed through coils heated to 90/sup 0/C, after which centrifugation followed by 2 more water washes and centrifugations left approximately 10% of the original NaOH to be lost by the NCl wash. The excess NaOH solutions from the centrifugations were combined and evaporated to 20% NaOh to recycle. The coke produced at 1200/sup 0/C had 0.6% ash, density of 1.84 g/cc, and a specific resistance of 400 Ohm-cm. A cost-profit analysis was determined, as was the coal recovery from the physical separation processes with regard to particle size and specific gravity of the aqueous CaCl/sub 2/ separating medium. 3 tables, 1 flowsheet.

• Research Organization: Corporate Unverified
• OSTI ID: 6710550
• Report Number(s): TOM-286-113-120
• Country of Publication: United States
• Language: German

Related Subjects

01 COAL, LIGNITE, AND PEAT
010401 -- Coal & Coal Products-- Carbonization-- (-1987)
010402 -- Coal
Lignite
& Peat-- Purification & Upgrading
010500* -- Coal
Lignite
& Peat-- Products & By-Products
010600 -- Coal
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ALKALI METAL COMPOUNDS
ASHES
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CARBONIZATION
CENTRIFUGATION
CHEMICAL REACTIONS
CLEANING
COAL
COKE
COKING
COMMINUTION
COST
DATA COMPILATION
DEASHING
DECOMPOSITION
DENSITY
DIAGRAMS
ECONOMIC ANALYSIS
ECONOMICS
ELECTRICAL PROPERTIES
ELECTRODES
ENERGY SOURCES
EXTRACTION APPARATUSES
FLOWSHEETS
FOSSIL FUELS
FUELS
GRINDING
GRINDING MACHINES
HYDROCHLORIC ACID
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
HYDROXIDES
INFORMATION
INORGANIC ACIDS
MACHINE TOOLS
MACHINING
NORMAL-MODE ANALYSIS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRODUCTION
QUANTITY RATIO
RECYCLING
REMOVAL
RESIDUES
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
TABLES
WASHING