Chemistry and reactivity of micronized coals. Technical progress report No. 2

This project examines the effect of reducing the mean size of coal particles to 1 to 10 microns, upon the physical and chemical behavior and reactivity of the coal. This second reporting period has been substantially involved with obtaining, installing and testing two pieces of equipment of major importance to this study. The Union Process Model S-1 stirred-ball slurry attritor mill was received in early February, has been installed and calibrated, and is fully operational. The Spectrex Model SPC-410 particle size analyzer has also been received in early February, has been calibrated, and is also fully operational. Two additional coals have been sampled, both as channel samples taken from active mines. This completes a suite of four adjacent major seams, KY No. 9, No. 10, No. 11 and No. 12. These coals have been reduced and characterized. A survey of the Hardgrove index values for a number of mid-continent coals in the PSU/DOE database has been made. Our preliminary sieve classification and milling experiments do not indicate this test to be a useful predictor of ease of mechanical reduction of mid-rank coals. Preliminary results on milling energy requirements, hydroliquefaction, physical beneficiation and storage stability studies are presented. One sample ofmore » dried micronized coal began smoking within minutes of its exposure to air. Work is continuing in all of these areas. The proximate and ultimate analyses of sieve fractions of an IL No. 6 coal show interesting disparities among the fractions: the -100/+200 mesh (75 to 150 micron range) fraction is lower in ash, and higher in ash-free carbon content, than either larger or smaller fractions from the same pulverized coal. These analytical data are validated by the excellent match between the weighted sums of fractional analysis and the direct analysis of the unseparated coal. We plan to pursue this with progressively reduced coals. 6 refs., 7 figs., 16 tabs.« less