EFFECT OF THE METHANE LEVEL ON THE POSSIBILITY OF EXTRACTING WALLS.

This paper presents a method of prognostic determination of the output volume to be obtained from a longwall working when taking into consideration the methane hazard. According to the proposed method, the methane level is calculated initially assuming the output volume to be equal to 500 t/24 hrs. The following are taken into account: the general dependence of the methane level in the longwall workings on the output volume, the possibility of fighting the methane hazard by ventilation means as well as the actual effectiveness of demethanizing procedures, and the uneven emission of methane into the workings. The results of a test of the method have confirmed its usefulness for predicting the possibility of extracting walls in deposits with a high methane hazard.