Abstract:
Deep mining in Shaanxi and Inner Mongolia mining areas is characterized by high mine pressure and high degree of broken coal. Leaving narrow coal pillars is easy to cause side air leakage along goaf, and the coal left in the adjacent gob will undergo oxidation reaction to form a hidden danger of coal spontaneous combustion. In order to grasp the spontaneous combustion characteristics of coal along the gob-side, taking Yingpanhao Coal Mine as an example, the characteristics of spontaneous combustion parameters and the variation of each gas in the process of coal oxidation were obtained through temperature-programmed primary oxidation and secondary oxidation experiments. The results show that the critical temperature range of raw coal and oxidized coal in 2201 working face of Yingpanhao Coal Mine is 70-80 ℃ and 65-75 ℃, and the cracking temperature range is 105-115 ℃ and 120-130 ℃. The critical temperature of oxidized coal was earlier than that of raw coal, and the cracking temperature lagged behind. By comparing the oxygen consumption rate and CO production rate during the two oxidation processes, the oxidation degree of oxidized coal was more severe than that of raw coal before 90-100 ℃, and the opposite was true after 90-100 ℃. It shows that coal spontaneous combustion of oxidized coal is more likely to occur in the low temperature stage, and thehidden danger of spontaneous combustion is more obviously. Therefore, by strengthening the monitoring of the spontaneous combustion of coal along the gob-side, the precise control and rapid emergency control methods for the spontaneous combustion of coal along the gob-side in Shaanxi and Inner Mongolia mining areas are proposed, and a combination of air leakage control, colloid pressure injection and liquid cooling CO2 is constructed, which has achieved advanced prevention and control of coal spontaneous combustion disasters along the gob-side, and effectively ensured that there is no fire along the gob-side and the safety of the local gob.