skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A novel technique for evaluating cleaned fine and ultrafine coal

Technical Report ·
DOI:https://doi.org/10.2172/5792610· OSTI ID:5792610

As a standard industrial practice all commercially cleaned coals are evaluated by washability analysis to predict their cleaning potential. The results of this analysis are so important that coal washability is a major factor in deciding to purchase and develop coal holdings. However, washability analysis are at present limited to coal particle sizes of greater than {minus}28 mesh (0.6 mm). Coal particles smaller than this limit do separate well in the standard sink-float process used in the washability tests. The increasing demand for cleaner coals requires that coals be crushed to fine ({minus}100 mesh - 0.15 mm) and ultrafine ({minus}325 mesh - 0.045 mm) sizes to liberate more of the fine-grained mineral matter including pyrite. However, such small coal particles can not be analyzed in the standard washability analysis. The purpose of this study is to develop a washability analysis system for fine and ultrafine coal particles using Density Gradient Centrifugation (DGC) and Thermal Gravimetric Analysis (TGA) techniques. The unique advantages of this proposed technique is that is provides a means to obtain usable washability curves on fine and ultrafine coal samples. The DGC technique will produce a large number of density fractions in a single run and, thus, is much faster and more efficient that normal washability analysis. During this quarter all of the samples to be used in this study have been ordered from the Illinois Basin Coal Sample Program and the initial results for one sample have been examined.

Research Organization:
Southern Illinois Univ., Carbondale, IL (United States). Dept. of Geology
Sponsoring Organization:
USDOE; ILDENR; USDOE, Washington, DC (United States); Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States)
DOE Contract Number:
FG22-91PC91334
OSTI ID:
5792610
Report Number(s):
DOE/PC/91334-T20; ON: DE92007872
Country of Publication:
United States
Language:
English