Characterization of size/composition and shape of fine coal and mineral particles

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6372860

Dumm, T F

Two techniques for determining the size/composition characteristics of fine coal were evaluated using a -200 mesh Lower Kittanning seam coal. The first was a fine coal washability analysis in which bulk samples were obtained by physically separating the coal into size fractions by sieving and specific gravity fractions using heavy liquids. Standard bulk chemical analysis techniques were used to determine the ash and total sulfur contents of the size/specific gravity fractions. This technique produced reliable chemical analyses but was time consuming and tedious. Heavy liquid absorption into the pore structure of fine coal particles appears to cause the apparent densities of particles to increase with time. The second technique applied to the coal used a scanning electron microscope coupled with an energy dispersive spectrophotometer (SEM/EDS). Applications of this technique to -10 {mu}M particles were subject to large errors due to variations in particle geometry. The results from SEM/EDS particle-by-particle analyses on +10 {mu}M coal particles appear to be inherently less accurate than bulk washability analyses because of the statistical counting errors incurred from particle-by-particle techniques. However, the SEM/EDS technique provides useful information on coal/mineral associations in the particles. A scheme for describing particle shape was developed in which shapes are classified according to their angular and elongational features and corresponding quantitative shape descriptors were defined. The shape features of particle profiles were measured using a polygon fitting technique which was incorporated into the SEM/EDS system. The technique was able to distinguish between rounded and angular particles and to quantify their specific shape features. The results were clearly consistent with visual observations of the particles.

• Research Organization: Pennsylvania State Univ., University Park, PA (USA)
• OSTI ID: 6372860
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ASH CONTENT
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CLASSIFICATION
COAL
COAL FINES
COAL PREPARATION
COMPARATIVE EVALUATIONS
CRYSTAL STRUCTURE
DENSITY
ELECTRON MICROSCOPY
ENERGY SOURCES
ERRORS
FOSSIL FUELS
FUELS
HEAVY MEDIA SEPARATION
MATERIALS
MEASURING METHODS
MICROSCOPY
MICROSTRUCTURE
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHYSICAL PROPERTIES
POROSITY
QUARTZ
SCANNING ELECTRON MICROSCOPY
SCREENS
SEPARATION PROCESSES
SHAPE
SILICON COMPOUNDS
SILICON OXIDES
SIZE
SORTING
SPECTROPHOTOMETRY
SULFUR CONTENT