察哈素3号煤低温氧化过程中煤孔隙特征变化发展规律研究
发布时间：2018-08-25 09:14
【摘要】：煤矿火灾是煤矿五大灾害之一,煤炭自然发火是其中的主要因素。在整个煤自燃过程中煤的具体结构变化尚未探究清楚,而低温氧化是整个自燃的初级阶段,在低温氧化过程中煤不论在宏观还是微观都发生了变化,包括煤的强度、发热量、吸氧量、产出气体、孔隙结构、官能团的一系列变化等,这些都与煤的孔隙结构特征密切相关。由于煤形成的漫长性和成煤地质、环境等条件的巨大差异,导致了煤内部孔隙结构复杂不规律性。测量孔隙结构的方法很多,其中压汞法是普遍应用的设备之一,本文采用压汞仪研究了低温氧化后察哈素3号煤的孔隙特征变化规律。为了研究煤样在低温氧化后的孔隙特征,实验选取察哈素3号长焰煤,煤种属不粘煤(BN31)和少量长焰煤(CY41)并筛选了4组不同粒径的煤样分别进行25~75℃低温氧化,然后用压汞仪进行测试,主要研究内容有:(1)不同粒径的煤样在不同温度条件下孔隙体积变化规律研究;(2)不同粒径的煤样在不同温度条件下孔隙比表面积变化规律研究;(3)低温氧化过程中煤样的分形维数变化规律研究。通过研究和分析得到了如下结论:(1)随着温度的升高煤样内部的孔隙进一步发育,孔隙体积随着温度升高增大;(2)通过分析煤样内部孔隙体积百分比随着温度的变化,得出煤样中4种不同类型孔的孔隙体积百分比随温度的变化趋势,其中小孔和大孔的变化趋势相反,但煤样的孔隙体积总体上以小孔和大孔分布为主;(3)煤的总比表面积基本上随着温度的升高而增大,影响着煤样总比表面积的主要是小孔和微孔,二者的比表面积百分比随温度的变化趋势相反;(4)4组煤样的分形维数随温度变化特征表明:煤样的分形维数在25~50℃时随温度升高增大,在50~75℃阶段又变小,说明煤表面先变粗糙而后变光滑。
[Abstract]:Coal mine fire is one of the five major disasters in coal mine, in which coal spontaneous combustion is the main factor. In the whole process of spontaneous combustion of coal, the specific structural changes of coal have not been clearly explored, and the low temperature oxidation is the primary stage of the whole spontaneous combustion. During the process of low temperature oxidation, both macroscopic and microscopic changes have taken place in the coal, including the strength and calorific value of the coal. Oxygen absorption, gas production, pore structure and a series of changes of functional groups are closely related to the pore structure characteristics of coal. Because of the long formation of coal and the great difference of geological and environmental conditions, the pore structure of coal is complex and irregular. There are many methods for measuring pore structure, among which mercury injection method is one of the most widely used equipment. In this paper, the pore characteristics of Chahasu No. 3 coal after low temperature oxidation are studied by mercury injection apparatus. In order to study the pore characteristics of coal samples after low temperature oxidation, Chahasu 3 long flame coal, which belongs to BN31 and a small amount of long flame coal (CY41), was selected for low temperature oxidation at 2575 鈩，
本文编号：2202424
[Abstract]:Coal mine fire is one of the five major disasters in coal mine, in which coal spontaneous combustion is the main factor. In the whole process of spontaneous combustion of coal, the specific structural changes of coal have not been clearly explored, and the low temperature oxidation is the primary stage of the whole spontaneous combustion. During the process of low temperature oxidation, both macroscopic and microscopic changes have taken place in the coal, including the strength and calorific value of the coal. Oxygen absorption, gas production, pore structure and a series of changes of functional groups are closely related to the pore structure characteristics of coal. Because of the long formation of coal and the great difference of geological and environmental conditions, the pore structure of coal is complex and irregular. There are many methods for measuring pore structure, among which mercury injection method is one of the most widely used equipment. In this paper, the pore characteristics of Chahasu No. 3 coal after low temperature oxidation are studied by mercury injection apparatus. In order to study the pore characteristics of coal samples after low temperature oxidation, Chahasu 3 long flame coal, which belongs to BN31 and a small amount of long flame coal (CY41), was selected for low temperature oxidation at 2575 鈩，
本文编号：2202424
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