Analysis on the influence of water immersion effect on spontaneous combustion tendency of anthracite

The spontaneous combustion of low-rank anthracite coal not only causes environmental pollution, but also seriously affects the progress and efficiency of coal mining operations. At present, the research on the spontaneous combustion process of anthracite only stays in the influence of external conditions on the natural process, while its internal mechanism and design of related engineering measures have been ignored. In order to solve these problems, in this paper, a self-built experimental device was used to study the influence of water immersion effect on the spontaneous combustion process of anthracite, and then, engineering measures to prevent uncontrollable spontaneous combustion of coal were proposed. Research results showed that spontaneous combustion of anthracite under the action of water immersion produced more CO2 but the difference in CO2 output was small. The final CO generation rate of the water-leached coal sample was 532.15 ml/s, while the final CO generation rate of the raw coal sample was only 176.34 ml/min. Water immersion has little effect on the amount of oxygen consumed by spontaneous combustion of anthracite. When the temperature was 180 degrees C, the oxygen consumption of anthracite when affected by the water immersion was 5 434.25 ml/min, and when the anthracite is not affected by the water immersion, the oxygen consumption was 5 451.67 ml/min. Water immersion will cause anthracite to produce more C-2 products during the spontaneous combustion process. This was mainly because the water immersion effect destroyed the surface microstructures of anthracite, resulting in more fractured surfaces being produced and exposed, so that the surface of anthracite has stronger polarity and activity. This research can provide theoretical support for the reduction of spontaneous combustion risk of anthracite and the improvement of mining efficiency.