Radon in the investigations of geo‐hazards in Polish collieries

Abstract

AbstractOutbursts (releases of gas and coal from exposed coal face) are dangerous events in coal mines, potentially leading to damage in the galleries and casualties among miners. For that reason, monitoring of this hazard is very important in collieries with seams prone to outbursts. Current hazard indicators are not sufficient for the proper prediction of geodynamic events and any effort to find a new and better method of monitoring is thus desirable. During the 1980s and 1990s, attempts were undertaken to apply specific radiometric methods to support the prediction of outbursts in collieries in the Lower Silesian Coal Basin (LSCB) in south‐western Poland. This idea was developed as an analogy to the study of radon changes in groundwater prior to earthquakes. This study investigates the hypothesis of possible variations of radon emanation from coal seams prior to outbursts. Techniques and a methodology of radon observation in gas samples from strata were developed and applied. It has been stated that there is a degree of correlation between the temporal and spatial variations of radon level and the hazard level of an outburst. In the 1990s, all collieries in LSCB were abandoned and further investigations were thus stopped. In the last few years, the occurrences of outbursts were noticed in the collieries of Upper Silesian Coal Basin. For that reason, we initiated the monitoring of radon concentration as sampled from headings in dangerous coal seams. The purpose of the research is an attempt to introduce a new parameter, ‘the radon indicator of outburst hazard’, which could be used to support other routinely applied techniques of outburst prediction. This study provides some results from previous investigations performed in the collieries of the LSCB, as background and calibration to the preliminary results of the new research, performed in one of the coal mines in Upper Silesia region.