低温氧化过程对不同变质程度煤的煤质特性的影响

Effect of Low Temperature Oxidation Process on Coal Quality Characteristics of Coal with Different Metamorphic Degrees

为探寻低温氧化过程中不同变质程度煤的煤质特性变化规律,通过煤质检测分析仪和坚固性系数测定装置,探究了不同变质程度煤体在低温氧化过程中煤质分析指标和坚固性系数的变化规律,探究了煤质分析指标与坚固性系数的交互影响关系。结果表明:煤的变质程度越低,在低温氧化阶段水分蒸发越慢,挥发分越容易挥发;随着氧化温度的升高,3组煤样的煤的坚固性系数f值都连续减少。水分蒸发对坚固性系数的影响主要体现在低温氧化前期,到了低温氧化的后期,挥发分挥发引起的裂隙发育,造成了坚固性系数的下降;而对于褐煤,在低温氧化后期f值下降速率增大,这主要是由于此时水分蒸发和挥发分分解共同作用所造成的。

The purpose of this paper is to explore the change law of coal quality characteristics of different metamorphic degree coals in the process of low temperature oxidation.Through the coal quality analysis index measuring system and firmness coefficient measuring device,the changing rules of coal quality analysis index and firmness coefficient of coal with different metamorphic degrees during low temperature oxidation were studied.The interaction between coal quality analysis index and firmness coefficient is explored.The results show that the lower the metamorphic degree of coal is,the more delayed the evaporation of internal water in the stage of low temperature oxidation is,and the easier the volatile matter is to volatilize and decompose.With the increase of oxidation temperature,the f values of the three groups of coal samples decreased continuously.The effect of water evaporation on the firmness coefficient is mainly reflected in the early stage of low temperature oxidation,and in the later stage of low temperature oxidation,the development of cracks caused by volatile matter volatilization results in the decrease of firmness coefficient.For lignite,the decreasing rate of f value keeps increasing in the middle stage of low temperature oxidation,which is mainly due to the joint effect of water evaporation and volatile decomposition.