【摘要】 注浆防火措施和岩层水造成国内许多矿区采空区遗煤经历长期水体浸泡,势必造成遗煤自燃规律有所变化.为研究采空区长期浸泡煤的自燃特性,以涡北煤矿8201工作面机巷原煤、8201风巷浸水煤为研究对象,从煤微观孔隙结构、官能团演化、氧化升温过程中气体生成规律及氧化动力学参数等方面展开实验研究.结果表明:经浸水风干后的煤体,矿物质含量呈减少趋势;煤中矿物质的溶解导致煤的孔隙结构发生变化,微孔比例增加,比表面积增大,总孔容减小.浸水风干煤体中的活性官能团数量增加,且在升温氧化过程中消耗速率更快;浸水风干煤样的TG-DSC曲线特征温度降低、氧化放热量增加;与原煤样相比,升温氧化过程中,浸水风干煤样的气体产物生成量、生成速率更高,交叉点温度由原煤的196℃降低到190℃,表观活化能由原煤的39.641 kJ/mol降低至39.100 kJ/mol,自燃倾向性增强.论文从煤体物理化学结构和宏观自燃特性变化角度探讨揭示了浸水过程对采空区遗煤自燃特性影响机理.研究结果可为近距离煤层群开采上覆采空区长期浸水煤的自燃防治提供参考.更多还原

【Abstract】 Grouting fire prevention measures and rock water have caused long-term water immersion in the goaf areas of many domestic mining areas,which will inevitably lead to changes in the spontaneous combustion of the residual coal. In order to research the spontaneous combustion characteristics of long-term soaked coal in the goaf,this paper takes raw coal from machine lanes of 8201 working face and immersed coal from 8201 wind lanes as research objects,and conducts research from the aspects of coal microscopic pore structure,functional group evolution,gas generation law and oxidation kinetic parameters. The results show that the mineral content of coal after being immersed and air-dried shows a decreasing trend. Mineral dissolution leads to changes in pore structure of coal,increased proportion of micropores,increased specific surface area,and decreased total pore volume. At the same time,the number of active functional groups in the water-immersed and air-dried coal increases,and the consumption rate increases as well in the self-heating process. The characteristic temperature of TG-DSC curve decreases,and the oxidation heat release of the immersed coal increases. Compared with raw coal,in the heating and oxidation process,the gas production amount and rate of immersed coal increase,the CPT decreases from 196 ℃ of the raw coal to 190 ℃,the activation energy deceases from 39.641 kJ/mol to 39.100 kJ/mol,and the spontaneous combustion tendency is enhanced. This paper reveals the influencing mechanism of water immersion process on the spontaneous combustion characteristics of the residual coal in the goaf from the perspectives of the physicochemical structure and the changes in macroscopic spontaneous combustion characteristics of coal. The research results can provide reference for the prevention and control of spontaneous combustion of long-term soaked coal in the overlying goaf in the short-distance coal seam group mining.更多还原