Experimental investigation of explosion-suppression properties of gob rocks under laboratory and mine conditions

During the period 2000 to 2007 a total of 120 fires occurred as a result of exoergic processes representing 60% of the total of 201 underground fires. The underground fires are the potential sources of explosions. Problems associated with an accident of explosions include the safety to human life, and the loss of coal reserves. Explosion tests were carried out at the “Granit” Experimental Mine in Galleries with cross section of 9.5 m2. These tests were carried out with air - methane mixture explosions, which dynamic pressures of 0.1 up to 0.3 MPa were generated. Methane content was 9.5%. The measuaring technigue in the galleries is correspondent to the standard equipment. The first result was that explosion suppression effectiveness by means of gob rocks, among other, depends on the rocks characteristics and emergency conditions, such as dynamic pressure of the explosion. The second result was that rocks guaranteed the effectiveness of 100% when its length becomes equal to 8 m.