Toxic substances from coal combustion - forms of occurrence analyses. Progress report, April 30, 1996 - November 1, 1996

摘要

The Pittsburgh, Elkhorn/Hazard, and Illinois No. 6 program coals have been examined to determine the mode of occurrence of selected trace elements using scanning electron microscopy, microprobe analysis, and experimental leaching procedures. Preliminary microprobe data indicates that the arsenic content of pyrite grains in the Illinois No. 6 and Pittsburgh coals is similar. Pyrite grains observed in the Elkhorn/Hazard coal generally have arsenic concentrations that are slightly higher than those of the Pittsburgh or Illinois No. 6 coals. One pyrite grain observed in the Elkhorn.Hazard coal contained much higher levels of arsenic. Preliminary microprobe analysis and data from leaching experiments indicate the association of arsenic with pyrite in the Pittsburgh and Illinois No. 6 coals. Leaching data fore arsenic in the Elkhorn/Hazard coal, in contrast, is inconclusive and additional data are needed before a definite determination can be made.