Page 313 - Advanced Mine Ventilation

290 Advanced Mine Ventilation

Table 17.1 History of Gas Outburst

Mass of
Depth Type of Volume of Coal
Coal Field/Country (ft) Gas Gas (MMCF) (ton) Year
1. Sydney, Canada 2340 CH 4 e e 1977
2. North Staffordshire, 2550 CH 4 e e 1904
UK
3. Gard, France 836 CO 2 e 1000 1907
4. Cevennes, France 2670 CH 4 14 1300 1947
5. Collinsville, 730 CO 2 e 900 1954
Australia
6. Lower Silesian, 2300 CO 2 26.5 5000 1958
Poland (appx)
7. Hokkaido, Japan 2700 CH 4 21.2 5300 1981

3. High ground stress in the rock mass including the coal seam (refer to Chapter 15).
4. Low compressive strength or fractured coal.
5. A very high diffusivity (a sorption time of less than 1 day).
6. A high gas thermal gradient. Temperatures much above the normal coal seam temperature
have been noted in the outburst areas [3]. High temperatures cause great increase in diffu-
sivity of the coal and hence large emission of gases in a short time.
7. Geological anomalies, such as faults, igneous intrusions, and clay veins, acting as barriers to
normal gas flow and emissions.
Table 17.1 lists some major gas outbursts in the past 100 years. There are only three
mining basins in the United States where gas outburst has occurred:
1. Carbondale and Somerset coalfields of Colorado.
2. Harlan coalfields of Kentucky.
3. Wasatch Plateau and Book Cliffs coalfields of Utah.
They are infrequent and not so disastrous. Overseas, it is a major and frequent
danger in the deep mines of China, Kazakhstan, Ukraine, Russia, Germany, and
Poland.

17.3 Parameters Indicating a Propensity to Gas
Outbursts

Imgrund and Thomas [7] provide a very good review of international parameters/
criteria for the prediction of gas outbursts. Each country has a slightly different strat-
egy. Some of them are highlighted here.