At many locations in the Pennsylvania – West Virginia coal regions, spontaneous combustion has resulted in fires smoldering in coal refuse piles. The burning piles emit noxious gases and smoke; in advanced stages, the burning can cause large voids and slope failures. The solution discussed is to:
– drive pipes into and through the affected zones.
– measure the underground temperatures using a geothermal probe in the pipes to delineate the extent of underground burning.
– inject a flyash/water slurry down through pipes driven into the burning zone to extinguish the fire and to cool the hot material.
– control the injection process and assure completion by a continuing program of temperature measurements.
This process has been applied on about ten refuse embankments. Quantities of flyash used have generally varied from 1000-3000 tons.