构造煤中有机质和无机质孔隙结构与瓦斯吸附特性关系研究

In addition to containing large amounts of organic matter, there are pore-rich kaolinite, clay and other inorganic minerals in the coal. Although there are a lot of research on the pore structure and specific surface area of the tectonic coal, the studies are confined to the total amount of pores and total specific surface area of coal. There is no study on the pore structure of organic matter and inorganic matter (mineral) and its specific surface area characteristics by the scholar. Based on the lipophilicity of the organic matter and the hydrophilicity of the inorganic matter in the tectonic coal, the project is intended to characterize the organic and inorganic pore structure and specific surface area properties of the tectonic coal quantificationally via the selective adsorption method（heavy hydrocarbon and water vapor）, meanwhile, multiple methods are combined to characterize the pore structure of the tectonic coal with low temperature N2 and CO2 and the mercury intrusion method, and the microscopic characteristics are also researched by Optical microscope（OM）,electron microscopy (SEM), atomic force microscope(AFM) , x-ray diffraction （XRD）and so on. And then, compared with the original structural coal for the research of the relationship between the organic and inorganic matter and the gas adsorption characteristics, which lays a foundation for deep understanding of the physical properties of tectonic coal and the occurrence and migration characteristics of gas in the tectonic coal. The results of this project will also provide a basis for explaining the tiny difference of actual gas content between the tectonic coal and the original structural coal in the same coal seam.

煤中除含有大量有机质外，还有富含孔隙的高岭石、粘土等无机质矿物。尽管对于构造煤孔隙和比表面积已有大量的研究，但这些研究仅仅局限在构造煤的孔隙总量及比表面积总量，尚无学者对构造煤中有机质和无机质（矿物）中的孔隙结构及其比表面积的特性进行研究。基于构造煤中有机质的亲油性和无机质的亲水性，本项目采用选择性吸附法（重烃、水蒸气）定量表征构造煤中有机质和无机质孔隙结构及比表面积特性，结合煤的总孔隙研究（低温N2、低温CO2、压汞法）、显微特性研究（光学显微镜（OM）、扫描电镜（SEM）、原子力显微镜（AFM）、X-射线衍射（XRD））等多种手段，研究有机质和无机质孔隙对瓦斯吸附能力的影响，并与原生结构煤进行对比，深入研究构造煤的物性特征和瓦斯在构造煤中的赋存和运移。本项目的研究结果也将对解释同一煤层中构造煤分层和原生结构煤分层的比表面积相差很大，而瓦斯含量相差并不大的现象奠定基础。

瓦斯在构造煤中的赋存和运移不仅受到煤中纳米孔隙、比表面积等的影响，也受到迂曲度、比表面积阻力及吸附作用的影响。对构造煤、非构造煤孔隙结构以及比表面积的研究对于深入理解瓦斯在构造煤中的赋存和运移规律有重要意义。煤中除含有大量有机质外，还有富含孔隙的高岭石、粘土等无机质矿物。基于构造煤中有机质的亲油性和无机质的亲水性，本项目以气肥煤、贫煤、无烟煤等三种典型不同变质程度煤为研究对象，采集同一煤层的构造煤和非构造煤，采用选择性吸附法表征有机质和无机质孔隙结构及比表面积特性。通过开展一部分探索性研究，发现九里山的构造煤和非构造煤用有机溶剂吡啶浸泡过后，在同一相对湿度下，浸泡时间越长，水蒸气吸附能力反倒降低；而九里山非构造煤用无机溶剂氨水浸泡后，其对水蒸气吸附能力却随着浸泡时间延长而增加。车集矿的构造煤用有机溶剂吡啶浸泡过后，在同一相对湿度下，浸泡时间对水蒸气吸附能力影响不大，但无论浸泡多少天，其吸附能力均高于原煤。由此说明，煤中有机质和无机质孔隙确实对煤的吸附能力有一定影响，且这种影响会根据不同煤种的变化而有所不同，今后可着重进行该部分研究。该研究结果将加深构造煤中孔隙结构及比表面积的认识，为深入理解瓦斯在构造煤和原生构造煤中赋存的差异性以及瓦斯在构造煤中的运移特性奠定基础。本项目的研究方法也将为今后研究全国范围内构造煤的孔隙特性奠定基础。