Methods for predicting gas outbursts in salt and coal mines

Gas outbursts occur as sudden eruptions of gas and minerals from the face of a mine heading as the heading approaches potentially burst prone (or anomalous) zones of rock. Such outbursts have resulted in considerable damage to equipment, and in some cases lives have been lost. Characterizing these anomalous zones and detecting their presence is therefore vital to safe mining. Certain significant characteristics associated with the outburst-prone zones are: (1) the presence of fluid inclusions, (2) unstable stress conditions, (3) characteristic geologic structures, (4) certain physical properties of the rock, and (5) microseismic activity. Geophysical and engineering methods for detecting these characteristics are discussed and are considered with respect to their past success and future potential for predicting gas outbursts.