煤自燃过程中自由基变化规律特性研究

Study on variation law and features of free radicals in coal spontaneous combustion process

为了研究在煤低温氧化过程中自由基的变化特性,选取了4种不同变质程度的煤样进行电子顺磁共振和升温氧化模拟试验。试验结果显示:不同煤种的自由基数量和CO产量存在很大的差距,褐煤CO产量最高,自由基浓度最低,贫煤反之。说明煤变质程度越低自由基数量越少,氧化过程中CO产量越大,临界温度越低,越容易自燃。因此自由基浓度也可以作为判定煤变质程度和氧化进程的指标,从微观反应揭示煤自燃氧化过程。

In order to study the variation features of the free radical in the process of the coal low temperature oxidation,four different metamorphic degree coal samples were selected to the simulation experiments of the electron paramagnetic resonance and the risen temperature oxidation. The experiment results showed that there were big differences in the free radical quantity and CO production value of coal with different metamorphic. The CO production value of the lignite was maximum and the free radical concentration was minimum. The meager coal would be on the contrary. Thus the lower metamorphic degree of coal was,the less quantity of the free radicals would be. In the oxidation process,the higher CO production was,the lower of the critical temperature would be and the easier of the spontaneous combustion would be occurred. Thus free radical concentration was found to be the index to judge the coal metamorphic degree and the oxidation progress. And the coal spontaneous combustion oxidation process was revealed from the micro reaction.