煤炭自燃自由基反应的电子自旋共振实验研究

Research on Free Radical Reactions in Spontaneous Combustion of Coal Using an Electron Spin Resonance

基于煤炭自燃的自由基作用机理，采用电子自旋共振（ESR）测谱仪，测定煤体在破碎和低温氧化过程中的自由基朗德因子，浓度，线宽和线高．实验以张集矿肥煤和白芨沟矿无烟煤为研究对象，分析了煤在4种粒径范围内ESR参数的变化情况和煤炭低温氧化过程中ESR参数随氧化温度、氧化时间的变化情况．结果表明：煤自由基因子在2．002～2．003之间，变化不大，张集矿肥煤的因子值稍大于白芨沟无烟煤；煤体粒径越小、氧化温度越高、氧化时间越长，煤自由基浓度越大；线高的变化趋势与自由基浓度变化趋势基本一致；线宽的变化趋势呈分散性．

Based on the free radical reaction mechanism of spontaneous combustion of coal, the parameters of coal free radicals, including Lande factor, concentration, line width and line height were measured using an electron spin resonance （ESR） spectrograph during the processes of being crushed and oxidated at low temperature. The materials studied in this experiment were from Zhangji coal mine（fat coal） and Baijigou coal mine（anthracite）. The changes of ESR parameters of coal for four different size ranges and the changes of them with the temperature and time during low temperature oxidation were analyzed. The results show that the Lande factors are 2. 002-2. 003, which have little change, and that of coal from Zhangji coal mine are little larger than that form Baijigou coal mine. Small particle size, high oxidation temperature and long oxidation time can lead to high corventration and high line height. However, the trend of line width is dispersive.