预报煤炭自燃的CO指标气体临界值研究

Critical Value of Index Gas CO for Coal Spontaneous Combustion Prediction

CO气体作为预报煤炭自燃的指标气体在煤矿中已被广泛使用,但有些矿井回采面上隅角始终存在CO气体,甚至超出矿业安全规定的临界指标,特别是在综采或综放工作面这一现象更明显,尽管采取多种防灭火措施,只能使CO气体涌出量减少而不能消除CO的产生,为了解其原因,在实验室做了不同煤种低温氧化实验,通过实验发现有些煤种在常温氧化条件下就会出现CO气体,甚至出现的CO量还很大,且随着煤的氧化时间的延长,产生CO气体强度在降低。为了及时准确、可靠预报煤炭自然发火,合理选择CO指标气体临界值是关键。利用多阀气相色谱仪检测常温条件下不同煤种氧化放出的CO气体量,对合理的CO指标气体的临界值进行了研究,确定不同情况下CO的临界值。

CO has been popularly used as an index gas to predict spontaneous combustion of coal in coal mines.But in some mines CO gas appears in the upper corner of mining face all the time,and sometime CO gas even exceeds the critical value regulated in Mining Safety Regulations.This phenomenon is much more obvious in fully-mechanized longwall and fully-mechanized longwall with top-coal caving.Although many fire control measures are taken,amount of CO gas can be only decreased,but appearance of CO can not be eliminated completely.In order to find the reasons,experiment of coal oxidation at low temperature with different kinds of coal samples was conducted in laboratory.Experiment showed that some kinds of coal samples produce CO under condition of normal temperature oxidation,even amount of CO production is very big,and intensity of CO production decreases with time increase.Determination of rational critical value of CO is the key to right and reliable prediction of spontaneous combustion of coal.By checking content of CO produced in oxidation of different kinds of coal samples under room temperature by using multiple valve gas chromatograph,reasonable critical value of index gas CO is studied,and then CO critical value under different conditions can be determined.