Coal is an important strategic resource in the world; coal production safety has always been widely concerned. In coal mine production, inert dust can effectively reduce coal dust explosion accidents in mine tunnels. To reveal the suppression effect of inert dust on lignite dust explosion, CaCO 3 , SiO 2 , and NH 4 H 2 PO 4 are selected for suppression experiments. It is found that the lignite dust explosion pressure decreases continuously as the mass percentages of inert dust mixed into lignite dust increase. By calculating the molar mass, the suppression effects of CaCO 3 and SiO 2 on lignite dust explosion are compared. The lignite dust no longer explodes when the mass percentage of NH 4 H 2 PO 4 dust mixed into lignite dust is 70%, indicating that NH 4 H 2 PO 4 is more effective than that of CaCO 3 and SiO 2 . The smaller the particle size of NH 4 H 2 PO 4 , the better the suppression effect on explosion. The lignite dust does not explode when the mass percentage of NH 4 H 2 PO 4 is 60% and the particle size of NH 4 H 2 PO 4 is 25–38 μm, which proves that decreasing the particle size of NH 4 H 2 PO 4 is important to suppress explosion. The research results are of great significance for grasping the explosion suppression effect of inert dust on lignite dust.

Nonstick coal is widely distributed in the world and is an important resource for human beings. The explosion characteristics and explosion suppression of nonstick coal dust are increasingly concerning. In this paper, the flame and pressure characteristics of a nonstick coal dust explosion are studied, and the suppression effect of SiO2, KCl, and NH4H2PO4 on the explosion is analyzed. It is concluded that the maximum propagation distance of a nonstick coal dust explosion flame is 0.59 m, the maximum pressure is 0.63 MPa, and the maximum pressure rise rate is 40.79 MPa/s. The explosion suppression effect of SiO2 is worse than that of KCl, but the inhibition effect of NH4H2PO4 is the best among the three kinds of explosion suppressants. When the mass percentage of NH4H2PO4 dust mixed with coal dust is 70%, the coal dust explosion is completely suppressed. It absorbs a certain amount of heat to promote the chemical reaction, which plays a certain role in controlling the explosion process, and its explosion suppression mechanism includes both physical and chemical explosion suppression.

Coking coal is a precious resource in the world and an important raw material for the production of steel, but it is easy to cause explosion accidents in the process of coking coal mining, which is very detrimental to safe production. In order to reveal the influencing factors of coking coal dust explosion intensity and the suppression effect of inert dust on coking coal dust explosion, an experimental study was carried out in this paper. The results show that the particle size and the mass concentration of coal dust have a great influence on the explosion pressure and flame. By analyzing the suppression effects of NaCl, KCl, and NH4H2PO4 on coking coal dust explosion, it is got that NH4H2PO4 has the best explosion suppression effect. When the mass percentage of NH4H2PO4 mixed into coking coal dust increases to 60%, the maximum explosion pressure decreases by 0.47 MPa, and the maximum flame length decreases by 0.50 m. As the particle size of NH4H2PO4 decreases, the explosion intensity continue to decrease. When the particle size of NH4H2PO4 is 0 ~ 25 μm, and the mass percentage of NH4H2PO4 mixed into coking coal dust is 50%, the explosion doesn’t occur anymore.

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 explosion 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 48~58 ?m, both the maximum pressure and the farthest distance of flame reach the maximum value. Among the three inert 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 0~38 ?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.