Coal cleaning employing quaternary salts: Final report, July 1, 1985-February 28, 1986
Investigation into a novel approach to coal desulfurization has continued. This approach is envisioned to include a treatment step to swell coal in quaternary salt solution, followed by physical separation, chemical reaction to desulfurize the coal, and recovery of the quaternary salt. The objective of the first step of the program was to define conditions under which complete exchange of quaternary salts with coal hydroxy groups occurs, define the extent of coal swelling and changes in coal properties as a function of amount of exchange, and determine the effect of process variation on swelling rate and coal properties. Results of this reaction have demonstrated that substantial coal swelling occurs in the presence of quaternary salts. The amount of quaternary exchange is a small portion of the total OH groups present in the coal. Swelling was found to depend on the concentration of quaternary salts, ratio of solution to coal, time of exchange (less than one hour), type and amount of solvent, pH, and coal composition, but was independent of particle size (<-60 mesh), temperature, and soak time < one hour. Recent data have shown that pyrite and inertinite can be concentrated after quaternary salt treatment. Excessive swelling with little exchange indicates that changes occur in the surface chemistry of the coal during reaction. Thus, oil agglomeration and froth flotation should be improved when coals are treated with quaternary salt. Optical microscopic analysis of the treated coals indicates that swelling and exchange are maceral dependent. In addition, swelling causes liberation of pyrite and inertinite which become isolated or exposed at edge/crack sites. Work is now concentrating on the development of mineral separation from coal and recovery of quaternary salt. 12 refs., 13 figs., 17 tabs.
- Research Organization:
- Southern Illinois Univ., Carbondale (USA). Dept. of Mechanical Engineering and Energy Processes
- DOE Contract Number:
- FC22-83FE60339
- OSTI ID:
- 6964307
- Report Number(s):
- DOE/FE/60339-T32; ON: DE87002790
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Coal cleaning employing quaternary salts: Annual report, March 1, 1986-February 28, 1987
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Related Subjects
COAL
CLEANING
SWELLING
COAL FINES
CHEMICAL COMPOSITION
PARTICLE SIZE
QUATERNARY COMPOUNDS
CHEMICAL REACTIONS
CORRELATIONS
DESULFURIZATION
EXPERIMENTAL DATA
GRINDING
MACERALS
MEDIUM TEMPERATURE
OPTICAL MICROSCOPY
PYRITE
RESEARCH PROGRAMS
TEMPERATURE EFFECTS
TIME DEPENDENCE
AMINES
AMMONIUM COMPOUNDS
CARBONACEOUS MATERIALS
CHALCOGENIDES
COMMINUTION
DATA
ENERGY SOURCES
FOSSIL FUELS
FUELS
INFORMATION
IRON COMPOUNDS
IRON SULFIDES
MACHINING
MATERIALS
MICROSCOPY
MINERALS
NUMERICAL DATA
ORGANIC COMPOUNDS
SIZE
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
010402* - Coal
Lignite
& Peat- Purification & Upgrading