SUPPRESSION EFFECT OF CaCO₃, NaCl, AND NH₄H₂PO₄ ON GAS-FAT COAL DUST EXPLOSION PRESSURE AND FLAME CHARACTERISTICS

Coal dust explosion is a major accident affecting the safety of coal mine production. In order to control coal dust explosion, using inert dust to suppress explo-sion is one of the effective methods. Taking the gas-fat coal as the research object and CaCO3, NaCl, and NH4H2PO4 as the inert dust, the suppression effect of inert dust on gas-fat coal dust explosion pressure and flame is studied. It is found that when the gas-fat coal dust particle size is 48 similar to 58 mu m, both the maximum pressure and the farthest distance of flame reach the maximum value. Among the three in-ert dusts, NH4H2PO4 has the best suppression effect, followed by NaCl, and CaCO3 has the worst suppression effect on explosion. The smaller the particle size of NH4H2PO4, the better the explosion suppression effect. When the mass percentage of NH4H2PO4 mixed into gas-fat coal dust is 60%, and the particle size of NH4H2PO4 is 0 similar to 38 mu m, the explosion is completely suppressed, it is mainly due to the isolation of the coal dust particles from the oxygen and the dilution of the oxygen concentration.