Mechanical and thermal friability of coals and modes of water bonding
The laboratory method developed to define mechanical and thermal friabilities of coals shows repeatable and consistent results. The method shows promise for prediction of a coal's behavior in various handling and thermal operations. This method is valid only if coals are compared with their intrinsic moisture intact, mine-fresh from an un-weathered surface; any predrying, however gentle, significantly reduces their friability. For this method to be valid, samples must consist of +1 in. (+2.5 cm) lumps, which must be uniform and representative of the vein, since significant variation occurs between different lithotypes. Intrinsic moisture, entrained in or bound to the coal is a positive factor contributing to the coal's structural integrity. Simply removing the moisture, with no concurrent damage by thermal expansion, substantially weakens to the coal. Differential calorimetry is a simple, effective method of determining comparative heats of wetting when a porous solid is immersed in a liquid. This exthermic heat is directly proportional to the specific surface of the solid. The only firm conclusion to be drawn from the friability and dielectric data together is that both are simple, numerical techniques to characterize and compare coals with respect to their mechanical structure and modes of intrinsic moisture attachment. Each provides sets of several variables, whose full significance can only be established after expanding the data base to include more coals. The accomplishment to date consists of demonstratng that such data are possible. 26 references, 3 tables, 16 figures.
- Research Organization:
- North Dakota Univ., Grand Forks (USA). Energy Research Center
- DOE Contract Number:
- FC21-83FE60181
- OSTI ID:
- 6492195
- Report Number(s):
- DOE/FE/60181-88; CONF-840924-2; ON: DE85001612
- Resource Relation:
- Conference: 4. international coal testing conference, Lexington, KY, USA, 10 Sep 1984; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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WETTING HEAT
WATER
BITUMINOUS COAL
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010600* - Coal
Lignite
& Peat- Properties & Composition