THE EFFECTIVENESS OF RAPID STONE DUST COMPLIANCE TESTING IN UNDERGROUND COAL

ABSTRACT: The addition of stone (limestone) dust to roadway dust in an underground coal mine increases the Total Incombustible Content (TIC) to reduce the potential of the coal dust igniting and propagating an explosion. Coal dust explosions have been proven to be one of the most severe hazards in an underground coal mine hence as Queensland legislation requires the use of roadway stone dusting, the required levels of TIC are higher than other mining districts around the world which also employ other coal dust explosion barriers. Compliance testing currently involves Low Temperature Ashing (LTA) of representative samples with a turn around on results of up to two weeks. To minimise the time that the mine is potentially out of compliance and unsafe, the Coal Dust Explosibility Meter (CDEM) has been tested at a Queensland underground coal mine to determine its effectiveness, through 11 different calibration methods, in rapidly measuring the TIC of roadway dust samples. The key focus of the calibration methods was to explore the effectiveness of the CDEM at its designed threshold of 80 % TIC, the use of an inbuilt methane content adjustment to replicate the Queensland legislative requirement of 85 % TIC and the use of actual 85 % TIC calibration samples. These calibration methods were replicated using both the manufacturer provided Pittsburgh coal dust an