影响煤氧化自燃的微观结构特征分析

Effect of micro structure characteristics on coal spontaneous combustion

为研究不同变质程度煤表面活性微观结构与氧化自燃能力的影响关系,揭示不同变质程度煤的微观自燃机理。采用X射线衍射仪、比表面积分析仪和扫描电子显微镜等实验分析手段,对褐煤、长焰煤、不粘煤、气煤、肥煤、焦煤、瘦煤、贫瘦煤和无烟煤等9种不同变质程度的煤样,进行XRD,比表面积和微观结构测试分析。结果表明:随着煤样变质程度升高,煤微观结构中的芳香层片尺寸变大,芳香层片的延展度和堆砌度则不断增强;煤的孔隙结构随变质程度的升高不断缩小,比表面积不断增大,煤的孔隙结构和表面积差异是引起不同变质程度煤氧化过程吸氧量不相同的主要原因,阐明了不同变质程度煤的微观结构的异同是影响煤低温氧化能力的主要因素。

To reveal the mechanism of micro coal spontaneous combustion, and study the relationship between the microstructure and spontaneous combustion ability of different ranks of coal, using X-ray diffraction, specific surface area analyzer and scanning electron microscopy method we tested the microstructure of 9 types of different ranks of coal. The results show that with the increase of coal rank, the size of the aromatic layer in the microstructure of coal increases, and the ductility and the degree of the aromatic layer are enhanced. The pore structure of coal decreases with the increase of coal rank, and the specific surface area is increased. The changes of pore structure and specific surface area are the main reasons for causing different quantity of respiratory oxygen in different ranks of coal during oxidation. Furthermore, microstructure is the main factor which affects the ability of low temperature oxidation.