Geology Reference
In-Depth Information
Figure 1.2.4. Combustion enhanced by excavating hot coal in the presence of an unlimited supply of oxygen.
Photo courtesy of the West Virginia Department of Natural Resources.
Figure 1.2.5. Excavation involves the hazards of working in hot material and toxic fumes. US Bureau of Mines
photo 1982, Calamity Hollow Burnout Control Project.
completely excavate the fire or to the failure to lower the temperature of backfilled material beyond the reignition
point (Kim and Chaiken, 1993).
Inundation methods of extinguishing wasted-coal fires involve the underground use of H
2
O to lower the tempera-
ture of the burning material (heat removal). Covering the burning material with H
2
O also stops the combustion
reaction by oxygen exclusion. To raise the H
2
O level, dams are constructed underground. The H
2
O level must
cover not only the burning coal, but must also reach the overlying heated rock. This method is limited to use on
fires that are small, fairly accessible, at or near the H
2
O table and have been burning for a relatively short time to
minimize the amount of stored heat. Another inundation method provides for the continuous flow of H
2
O through
the hot material. This can be accomplished by continuous pumping or by gravity flow from a surface impound-
ment. The volume of H
2
O required, the cost of high-capacity pumps, and time considerations have limited the
utility of continuous pumping.
