氧含量对煤体低温氧化过程中自由基的影响

Effect of oxygen content on free radicals during low-temperature oxidation of coal

针对不同地质条件所形成的不同变质程度的煤体,为了探究矿井采空区不同氧含量对煤低温氧化过程中自由基变化的影响规律,通过配置不同氧含量的混合气体,测定褐煤、烟煤和无烟煤在不同氧含量下的自由基变化特性,从而对不同变质程度的煤体在不同氧含量下的自燃特性进行分析。结果表明:不同变质程度的煤体在无氧氛围下均能发生自由基反应;随着氧含量的增加,褐煤线宽升高,烟煤、无烟煤线宽降低,3种煤体的g因子、自由基浓度和自由基浓度相对增长率均增大。通过分析,提出以自由基浓度相对增长率和g因子代替自由基浓度来评价煤体的自燃氧化能力,且得出褐煤中的自由基反应较高变质程度的烟煤和无烟煤具有更强的氧气敏感性。

For coal bodies with different metamorphic degrees formed under different geological conditions, in order to explore the influence of different oxygen content in the goal of the mine on the change of free radicals in the process of coal low-temperature oxidation, the free radical change characteristics of lignite, bituminous coal and anthracite under different oxygen content were measured by configuring mixed gases with different oxygen content, so as to analyze the spontaneous combustion characteristics of coal bodies with different metamorphic degrees under different oxygen content. The results show that free radical reactions can occur in an oxygen-free atmosphere for coal bodies with different degrees of metamorphism. With the increase of oxygen content, the line width of lignite increases, while that of bituminous coal and anthracite decreases. With the increase of oxygen content, the g-factor, free radical concentration and relative growth rate of free radical concentration of the three coal bodies increase. Through analysis, it is proposed to use the relative growth rate of free radical concentration and g-factor instead of free radical concentration to evaluate the natural oxidizing ability of coal, and it is concluded that the free radical reaction in lignite has stronger oxygen sensitivity than in bituminous coal and anthracite with a higher degree of metamorphism.