Effects of particle size and oil-immersed concentration on the dust layer minimum ignition temperature and combustion characteristics of oil-immersed coal

This paper studied the minimum ignition temperature of the dust layer (MITL) of oil-immersed coal and the heat effect and apparent activation energy (E_a) of raw coal and oil-immersed coal. Based upon the results, the addition of crude oil to coal could reduce the MITL, ameliorate the ignition sensitivity, and increase the heat effect of coal dust. The average E_a of oil-immersed coal was lower than that of raw coal. When there was a 10.8 mass% oil-immersed concentration of oil-immersed coal with the most acceptable particle size (≤ 75 μm), the MITL was 24.24% lower than that of raw coal. Furthermore, the exothermic value of oil-immersed coal was 26.67% higher than that of raw coal. Besides, the average E_a of oil-immersed coal was 26.8% lower than that of raw coal. The research herein is expected to improve people’s understanding of the thermal hazard characteristics of oil-immersed coal dust, reduce the risk of coal dust fires and explosions, and ensure production safety.