不同深度煤层煤质变化对自燃影响研究

Study on the influence of coal quality change on spontaneous combustion in the same coal seams with different depths

为了探究深部煤层煤质变化对煤自燃的影响,采用试验分析和氧化动力学分析的方法,选取济宁矿区4个煤矿成煤时期3#煤层不同埋深煤样进行工业分析、红外光谱测试及热重试验,测试其物质组分、含氧官能团变化规律,对其氧化过程中的增失重过程及氧化动力学参数差异进行分析。结果表明:挥发分质量分数随煤层埋藏深度增大而增加,灰分、水分规律不明显,干燥无灰基固定碳质量分数呈下降趋势;4个煤矿煤样羟基峰面积随埋深增加而增加,羟基增幅随区域差异变化较大,距离较近的运河煤矿、二号井煤矿羟基峰面积增幅较大,阳城煤矿、古城煤矿增幅较小;同一煤矿煤样浅部特征温度点高于深部煤层;随埋深增加,同一煤矿煤样所需的活化能E降低,自燃倾向性增大。上述规律表明,埋深增加,煤质发生变化,一定程度上使得深部煤层的氧化活性增大。

Using experimental analysis and oxidation kinetics analysis,the change of coal quality in deep coal seam and its influence on coal spontaneous combustion were studied.In the experiment,the composition and oxygen-containing functional groups of coal samples with different burial depths of No.3 coal seam in the same coal forming period in the Jining mining area were analyzed by proximate analysis and Fourier transform infrared spectroscopy.The weight loss process and the oxidation kinetic parameters of coal samples were also analyzed by a thermogravimetric analyzer.The proximate analysis results show that the volatile content increases with increasing the burial depth of coal samples in the same coal seam;The fixed carbon content shows a downward trend with the increase of the burial depth;The law of ash and moisture is not obvious;The Fourier transform infrared spectroscopy results show that the hydroxyl peak area of coal samples in the same coal seam increases with the increase of the burial depth;The increasing degree of the hydroxyl group changes greatly with the region.The hydroxyl peak area of the adjacent Yunhe Coal Mine and No.2 well coal mine increases significantly.Those of relatively distant Yangcheng coal mine and Gucheng Coal mine increase slightly.The thermogravimetry results show that the temperature characteristic points of shallow coal seam were higher than those of deep coal seam in the same mine;In the same mine,with the increase of burial depth,the activation energy E of coal samples decreases,indicating that the spontaneous combustion tendency of coal increases with the increase of the burial depth.In short,the rules show that with the increase of the burial depth,the coal quality changes,and the oxidation activity of deep coal seam increases to a certain extent compared with shallow coal seam,which can provide a reference for prevention and control of spontaneous combustion in deep coal seams.