氧化煤自燃特性实验研究

为解决大柳塔煤矿活鸡兔井12下208综放工作面采空区存在大量氧化煤的遗煤自燃预测问题，对原煤及不同程度的氧化煤进行程序升温实验，分析研究低温氧化特性的变化规律，根据灰色理论对自燃标志气体进行优选。结果表明:原煤与氧化煤的临界温度与干裂温度相差不明显，分别在40~50 ℃与110~120 ℃之间；根据临界温度、干裂温度及其指数增长点将煤低温氧化过程分为缓慢自热（50~＜90 ℃）、加速自热（90~＜120 ℃）、热解裂变（120~＜160 ℃）和热解加速（160~＜200 ℃）4个阶段。在缓慢自热阶段以G2（0.01~＜0.039）和R1（0.001 5~＜0.007 7）为指标；在加速自热阶段以R1（0.007 7~＜0.019 5）和G3(0.000 9～＜0.003 7)为指标；在热解裂变阶段以烯烷比（0~＜0.484）和G3（0.003 7~＜0.037 4）为指标；在热解加速阶段以R1（0.046 8~＜0.072 6）和烯烷比（0.484~＜0.992）为指标气体。实验结果对采空区遗煤的自燃防治具有一定的指导作用。

Experimental study on spontaneous combustion characteristics of oxidized coal

In order to solve the problem of predicting the spontaneous combustion of residual coal for a large amount of oxidized coal existing in the goaf at 12 underground 208 fully mechanized caving face of Huojitu well in Daliuta coal mine,the temperature programmed experiments were carried out on the raw coal and the oxidized coal with different degrees.The change laws of low temperature oxidation characteristics were analyzed,and the index gases of spontaneous combustion were optimally selected according to the grey theory.The results showed that the critical temperatures and dry cracking temperatures of raw coal and oxidized coal were not significantly different from each other,which was between 40~50 ℃ and 110~120 ℃,respectively.According to the critical temperature,dry cracking temperature and its exponential growth point,the low temperature oxidation process of coal was divided into four stages,namely the slow self heating （50~＜90 ℃）,accelerated self heating （90~＜120 ℃）,pyrolytic fission （120~＜160 ℃） and pyrolysis acceleration （160~＜200 ℃）.In the slow self heating stage,G2（0.01~＜0.039） and R1（0.001 5~＜0.007 7） were used as the indexes.In the accelerated self heating stage,R1（0.007 7~＜0.019 5） and Ｇ３（０．０００ ９～＜０．００３ ７） were used as the indexes.In the pyrolysis fission stage,the ratio of alkenes to alkanes （0~＜0.484） and G3（0.003 7~＜0.037 4） were used as the indexes.In the accelerated self heating stage,R1（0.046 8~＜0.072 6） and the ratio of alkenes to alkanes （0.484~＜0.992） were used as the indexes.The experimental results have a certain guiding role for the prevention and control on spontaneous combustion of residual coal in the goaf.