Early Detection of Spontaneous Combustion at Sumitomo-Akabira Colliery

At Akabira Colliery, the instance of fire fightings for mine fire tells one side of the history of the colliery since the mine was opend. Six mine fires which have occured in the colliery in the past seven years resulted from spontaneous combustion of the residual unmined coal around operating areas. In every case such as the fire could not be detected in early stage and was not extinguished by direct water spraying, the firing zone was immediately sealed off from the other area. The accumulated experiences in our mine have suggested that the early detection of spontaneous combustions of coal is important countermeasures and is able to minimize the trouble.This paper gives an account of early detection methods of spontaneous combustions and typical countermeasures applied at Akabira Colliery. It reports, in addition, the most up-to-date methods for early detection in spontaneous combustion and the prospect for the development of underground integrated monitoring system.