Influence of Volatile Content on the Explosion Characteristics of Coal Dust

To study the influence of different volatile contents on the explosion characteristics of coal dust, the volatile content in coal dust was controlled under different final temperatures of pyrolysis. The maximum explosion pressure, maximum pressure rising rate, and explosion index were used to characterize the pressure behavior, the pressure ratio to characterize the explosibility, and the minimum ignition temperature of the coal dust cloud to characterize the sensitive characteristics. A 20 L of nearly spherical coal dust explosion parameter measuring device and a dust cloud minimum ignition temperature measuring device were used to study the influence of the explosion characteristics of dust with different volatile contents prepared under different pyrolysis temperature conditions. The results showed that the volatile matter content in lignite dust has little effect on the maximum explosion pressure, with an average change rate of 5.435%. When the volatile content was reduced from 45.4 to 2.45%, the maximum explosion pressure rise rate dropped by 65.976%. The explosion index of the experimental sample was in the range of 0-1.6, with weak explosion characteristics; the lower the volatile content, the weaker the explosion intensity. When the volatile content was only 2.45%, the pressure ratio was still greater than 2, that is, the dust was still explosive. When the volatile content in lignite was reduced from 45.4 to 18.21%, the lowest ignition temperature of the dust cloud was consistently 490 °C. At this stage, the contents of H₂, CO, CH₄, CO₂, and other precipitated dases were low. When the volatile content was reduced from 18.21 to 2.45%, the precipitated volatile gas increased rapidly, the remaining precipitated gas content decreased, and the dust could not be easily ignited. The experimental results lay the foundation for studying the influence mechanism of volatile matter in coal dust on the explosion characteristics.