含水量对长焰煤氧化自燃特性的影响实验研究

Experimental Study on Influence of Moisture Content on Oxidation Spontaneous Combustion Characteristics of Long-flame Coal

为研究不同含水量对煤氧化自燃特性的影响,对原煤及含水量为2%、4%、6%、8%、10%的煤样开展了程序升温实验和热重特性实验研究。综合分析了不同含水量煤样的气体产生量、质量损失、温升特征以及自燃倾向性的变化规律,指出了含水量对煤氧化自燃进程的影响。结果表明:10%以内的含水量能够使煤在较低温度条件下更容易被氧化,加快了煤氧复合反应的进程,同时水分蒸发过程吸收热量,增大了内部气压,使氧气吸附受阻,随着温度升高,氧气不断消耗,更多的活性基团不能及时的充分反应,从而延缓了煤分子进一步剧烈氧化,阻碍了煤氧复合反应的进程;随着含水量的增加煤样自燃倾向性不断下降,在含水量大于8%时下降趋势加快。

In order to study the effect of various moisture content on the spontaneous combustion characteristics of coal, the temperature programming experiment and thermogravimetric characteristics experiment were conducted for coal samples with moisture content of 2%, 4%, 6%, 8% and 10%. The variation of gas production, mass loss, temperature rise and spontaneous combustion tendency of coal samples with different moisture content were analyzed comprehensively. It points out the influence of the moisture content on coal spontaneous combustion process. The results show that a certain amount of moisture enables the coal to be more easily oxidized at lower temperature, accelerating the process of coal-oxygen complex reaction. At the same time, the moisture evaporation process absorbs heat, and increases internal pressure, oxygen adsorption blocked, as the temperature rises, oxygen is constantly depleted, more active groups cannot be fully reacted in time, thus delaying the further vigorous oxidation of coal molecules, hindering the process of complex reaction of coal and oxygen. Coal spontaneous combustion tendency continues to decline with the increase of moisture content, when the moisture content is greater than 8%, the declining trend is accelerated.