Safety tests with methane and coal-dust

SAFETY TESTS WITH METHANE AND COAL-DUST 

Explosives for use in coal mines containing methane or ignitable coal-dust must pass a test in a testing gallery. Different procedure is used in different countries. General data on galleries and methods of testing are summarized in Table 108. 

Throughout the length of the gallery there is a floor of sheet iron with an empty space below filled with concrete except for the first three meters from the closed end, where the heating pipes are situated. 

Inside the gallery, at a distance of 3.4 m from the closed end a ring is fixed to which a paper partition is fastened so as to form a chamber of 10 m3. In the chamber a mixture of methane and air is prepared. In winter this is heated to a temperature of above 0°C by steam in the heating pipes beneath the floor. 

In the wall of the gallery facing the observation post there are observation windows at intervals of 1 and 2 m along its whole length, through which the course of firing is watched. 

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Inert ingredients increasing safety Inert neutralizing agents Tests for mining explosives Transmission of detonation Sensitiveness to detonation Power of explosives Safety tests with methane and coal-dust Experimental gallery in Poland Experimental gallery in U.5.S.R. 

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