潞宁矿区2~#煤层自燃指标气体优选的试验研究

以潞宁矿2#煤层煤样为研究对象,通过程序升温试验,研究不同气体在煤氧化过程中的变化规律,具体分析了CO、C2H4、CO/CO2体积分数随温度变化特性。试验结果表明:潞宁矿区2#煤层煤产生CO的临界温度为30℃,从80℃开始CO体积分数呈持续稳定上升趋势,C2H4出现的温度为160℃左右,CO/CO2体积分数比从80℃时生成速率迅速增加。因监测中难以准确分析气体在采空区的真实体积分数,所以同一组气样体积分数比对于预测煤自燃具有重要意义。因此,潞宁矿区2#煤层检测煤炭自燃的标志气体应以CO为主,CO/CO2为辅。当煤温达30℃时,应加强CO体积分数监测;当CO体积分数达1.8×10-5,CO/CO2体积分数比为1时,应发出煤炭自燃预警并采取有效的防灭火措施。

Experiment Study on Index Gas Optimal Selection of Coal Spontaneous Combustion in Luning Mining Area 2~# Coal Seam

Based on coal samples from Luning Mining Area 2#coal seam as the study objects,the programmed temperature rising test was applied to the study on the variation laws of different gases during the coal oxidized spontaneous combustion process。 The changing rule of CO,C2H4, CO/CO2 volume fractions with temperature change is analyzed specifically. The test results showed that the critical temperature of CO produced from Luning coal 2#coal seam was 30 ℃, volume fractions of CO had a steady upward trend from 80 ℃, the temperature of C2H4 appeared was about 160 ℃, the ratio of carbon monoxide and carbon dioxide increased rapidly in temperature rise at 80 ℃. Because monitoring is difficult to accurately analyze the real volume fractions of gas in goaf,so the same set of sample gas volume fractions ratio is of great significance for predicting coal spontaneous combustion. Therefore, the index gas to check the coal spontaneous combustion in Luning Mining Area 2#coal seam would be CO mainly and CO/CO2 secondly. When temperature of coal reached 30 ℃, volume fractions of CO should be strengthen monitored; When the volume fractions of CO up to 1.8×10-5, the ratio of carbon monoxide and carbon dioxide to 1, the early warning of coal spontaneous combustion should be issued and the effective measures for fire prevention should be taken.