Physical properties and moisture

Conference · Mon Jul 01 00:00:00 EDT 1985

OSTI ID:5593052

Schobert, H H; Tye, C; Neumann, R M

Our principal accomplishments in the physical property studies of low-rank coals are the determination of their: (A) relative amounts of tightly and loosely bound moisture, (B) porosity and pore size distribution, (C) mechanical and thermal friabilities, and (D) surface areas. The occurrence of moisture in low-rank coals involves at least two fundamentally different mechanisms for binding the water to the coal matrix. The first type of moisture behaves as if it were ''free''; the vapor pressure versus temperature behavior is similar to that of pure water. The second type occurs at sites where it is bound more tightly, resulting in a lowering of the corresponding vapor pressure. A dielectric-relaxation-spectroscopic investigation of a North Dakota lignite and a subbituminous coal provides direct evidence for the existence of the two types of moisture. Lignite incorporates 80% of its moisture in a loosely-bound form which freezes to ice and the remaining 20% is present possibly chemically bound to inorganic moieties. The subbituminous coal contains only the latter type of bound moisture. Small angle scattering has proven to be a useful and convenient method of studying the pore structure of coal, and yields information related to pore size, pore size distribution, specific surface area and specific volume. Calculation of values for these parameters must be made in terms of some model; a pore model developed at the University of Missouri has proven to be quite useful. The objective in friability studies is to determine the shift in particle size distribution as a result of tumbling or heating. 6 figs., 2 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy Research Center
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 5593052
• Report Number(s): DOE/FE/60181-156; CONF-850878-1; ON: DE85015593
• Resource Relation: Conference: AR and TD direct utilization contractors' meeting, Morgantown, WV, USA, 13 Aug 1985
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
COMPARATIVE EVALUATIONS
DIELECTRIC PROPERTIES
MECHANICAL PROPERTIES
MOISTURE
SMALL ANGLE SCATTERING
SURFACE AREA
WETTING HEAT
MEASURING METHODS
COAL RANK
EXPERIMENTAL DATA
LIGNITE
METHANOL
SUBBITUMINOUS COAL
X RADIATION
ALCOHOLS
BROWN COAL
CARBONACEOUS MATERIALS
DATA
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROXY COMPOUNDS
INFORMATION
IONIZING RADIATIONS
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
SCATTERING
SURFACE PROPERTIES
010600* - Coal
Lignite
& Peat- Properties & Composition