The Release Law Of Stope Multi-Source CO And Modification Of Coal Spontaneous Combustion Prediction Critical Value

Aiming at the problem of false alarm of coal spontaneous combustion,in order to clarify the disturbance of CO that precision forecasting coal spontaneous combustion,coal pyrolysis and oxidation of CO gas desorption test system was designed to study the law of CO that may appear during coal spontaneous combustion,consist of T-CO,O_N-CO,O_T-CO,P_S-CO,P_T-CO,take HM,FM,WYM into consideration.By setting different working conditions,three kinds of coal samples with different metamorphic degrees can be generated in the process of coal mining and coal spontaneous combustion,which may cause different causes of CO generation and change characteristics.When to non-thermal-origin CO gas:all the three coal samples with different metamorphism can produce O_N-CO gas at normal temperature and air contact.At the initial stage,CO gas volume fraction rises rapidly and then rises slowly until it reaches equilibrium.P_S-CO gas also exhibits a similar rule.When to CO of thermogenic gas:1)three kinds of coal heating under the nitrogen atmosphere,have begun to release CO gas,HM:140?,FM:163?,WYM:183?at 200?,then with the increase of temperature,the volume fraction of CO gas is four times the regression curve of growth;2)heating in air atmosphere,OT-CO gas produced in large quantity,high speed,three coal samples respectively from 55?,68?,77?began to produce,then with the increase of temperature,the volume fraction of CO gas is four times the regression curve of growth;3)Take HM as the research object,different equilibrium pressure of coal in pure nitrogen atmosphere under heating P_T-CO,the begining temperature to release gas is from 45?to 50?,and the feature is piecewise as the temperature rises,and then also obtained the release quantity and coal temperature by fitting equation.The absolute quantity of the non thermal CO gas in the laboratory is calculated.A calculation method of coal mining face falling speed and non heat causes CO to produce the absolute amount,and the calculation formula of working surface modified non thermogenic CO concentration and CO concentration change rate,correction results will improve the utilization of mining face CO concentration prediction of coal spontaneous combustion in the accuracy.