煤低温恒温氧化过程反应特性的试验研究

为进一步揭示煤低温氧化机理、指导煤矿安全开采过程中的煤自燃火灾防治工作,根据CO,CO2是煤低温氧化的主要气体产物这一反应特性,同时CO是判断煤自燃程度的重要指标性气体这一工程实际,采用恒温试验方法研究某烟煤在30℃,50℃和70℃解吸附和解吸附后再氧化过程中的CO,CO2气体产物的产生特性。研究结果表明,新鲜煤中就存大量活泼的络合物,并且这种络合物在高于常温的情况下就可以自身发生分解,产生的主要气体产物为CO2,在较高的温度下,CO的生成量才逐渐增加;在煤的低温氧化阶段,煤与氧气发生的化学反应并不强烈,气体产物CO和CO2主要由络合物分解产生。因此,在煤自燃火灾防治时要及时控制煤在低温情况下,由于络合物分解放热而使煤温逐渐升高从而导致自燃发生。

Experimental Study on Reaction Characteristics of Coal during Low Temperature Oxidation in Isothermal Flow Condition

To further reveal the mechanism of coal oxidation in low temperature,isothermal flow method was used to study the production characteristics of CO and CO2 during the process of desorption and oxidation at 30℃,50℃ and 70℃,respectively,based on the fact that CO and CO2 are the main gas products of coal oxidation in low temperature and that CO is the key index gas in judging the degree of coal combustion in engineering practice.The results show that there are plenty of active complexes existing in raw coal.The active complexes will decomposition when the ambient temperature is higher than normal temperature and CO2 is the main gas production.Activation energy of the complexes to generate CO is higher than that to generate CO2 for the production of CO becomes more in higher temperature.It is also indicates that CO and CO2 are mainly generated from active complexes during the oxidation of coal in the low temperature.Therefore,the prevention of spontaneous combustion of coal should be focused on the decomposition of complexes in low temperature.