Abstract
Studies show that pre-combustion physical cleaning can substantially reduce the trace element contents of a given coal. Using an advanced fine coal cleaning circuit comprised of an enhanced gravity separator (EGS) and a flotation column, over 80% of the Hg and Se contents of a -250 μm Illinois No. 6 coal sample were rejected while achieving an energy recovery of 80%. According to a statistical correlation evaluation, this performance was achieved due to a strong affinity of the Hg and Se with the ash forming and coal pyrite particles, which were rejected at rates of 84 and 83%, respectively. However, Cr was found to have a moderate affinity with the organic material, which limited its rejection to 62%. Treatment of a pre-cleaned pulverized coal combustion boiler feed sample originating from the same Illinois No. 6 coal seam provided an additional reduction in total sulfur and trace element contents. Overall, the EGS-Column circuit was found to be effective in reducing the amounts of three trace elements found in coal that have been identified as potential air toxics, which are emitted into the air during the coal combustion process.
Original language | English |
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Pages (from-to) | 195-211 |
Number of pages | 17 |
Journal | Coal Preparation |
Volume | 19 |
Issue number | 3-4 |
DOIs | |
State | Published - 1998 |
Bibliographical note
Funding Information:The work presented in this publication was funded in part by grants made possible by the U. S. Department of Energy Cooperative Agreement Number DE-FC22-92PC92521 (Year 3) and the Illinois Department of Commerce and Community Affairs through the Illinois Coal Development Board and the Illinois Clean Coal Institute (Project No. 94-1/1.1B-1 P). The authors also acknowledge the assistance provided by Dr. Hasan Sevim for the statistical evaluation and Mr. Richard Voyles for technical assistance during the test program.
Keywords
- Air toxic
- Column flotation
- Correlation coefficient
- Enhanced gravity separator
- Sulfur emission
- Trace element
ASJC Scopus subject areas
- Fuel Technology
- Geotechnical Engineering and Engineering Geology