韩城矿区构造煤分子结构演化特征

发布时间：2018-05-07 17:34

  本文选题：结构缺陷 + 自由基浓度　； 参考：《太原理工大学》2016年硕士论文

【摘要】：煤是一种复杂的大分子有机岩石,对周围环境的应力十分敏感。煤受到构造应力作用,形成了不同变形特征的构造煤。构造煤的宏观变形特征与分子结构的演化与原生结构煤都不相同。宏观变形上,从脆性变形煤到韧性变形煤,原生结构的保存程度越来越差,粒度也越来越小,手拭强度也越来越小,宏观煤岩组分也越来越难以辨认。构造煤结构上原生层理结构慢慢变差,逐渐表现出擦痕、阶步,鳞片状和揉皱状的结构。与原生结构煤相比,碎裂煤发育着有利煤层气扩散和渗流的较大的裂隙结构,而碎粒煤和糜棱煤因破碎变形严重而无法观察到裂隙发育状况。在变质变形过程中,构造煤的分子结构演化具有一定的规律性。利用拉曼光谱、电子顺磁共振波谱和红外光谱对构造煤的分子结构演化特征进行分析。构造煤的拉曼光谱分析,可以定性地表征次生结构缺陷变化规律。随着构造煤R_(o,max)的增大,构造煤分子的结构缺陷发生规律变化。脆性变形煤D峰面积逐渐增加,碎裂煤D峰面积增加幅度大于碎粒煤,韧性变形煤的D峰面积逐渐减小。在脆性变形机制下,G峰面积随构造煤R_(o,max)的变大而迅速升高,碎裂煤的增长速度较大。韧性变形煤的G峰面积增长缓慢。造成这种现象的原因可能是构造应力对煤的分子结构的降解和缩聚作用。通过对构造煤的电子顺磁共振波谱分析发现,不同类型构造煤的演化规律具有差异。碎裂煤自由基浓度随变质程度升高而降低;碎粒煤表现为先降低后升高;糜棱煤的自由基浓度表现为N型演化特征。通过对构造煤红外光谱分析发现,随变质变形作用的增强,构造煤的芳香结构的Ⅲ类氢原子含量增加,而Ⅳ类氢原子含量减少,芳香环缩合程度提高,而脂肪结构和含氧官能团含量减少。利用波谱学原理对构造煤分子结构分析,发现在构造应力作用下,构造煤分子结构具有明显的演化规律。
[Abstract]:Coal is a kind of complex macromolecular organic rock, which is sensitive to the stress of surrounding environment. Coal is subjected to tectonic stress, forming tectonic coal with different deformation characteristics. The macroscopic deformation characteristics and the evolution of molecular structure of tectonic coal are different from that of primary coal. In macroscopic deformation, from brittle deformed coal to ductile deformed coal, the preservation degree of primary structure is getting worse and worse, the particle size is becoming smaller and smaller, the hand wiping strength is becoming smaller and smaller, and the macroscopic coal and rock components are becoming more and more difficult to identify. The primary bedding structure in the structural coal structure gradually becomes worse, and gradually shows the structure of scratch, step, scale and crinkle. Compared with the primary coal, the fractured coal has a large fracture structure which is favorable to the coalbed methane diffusion and percolation, while the broken coal and the minced coal can not be observed because of the serious crushing deformation. In the course of metamorphic deformation, the evolution of molecular structure of tectonic coal has certain regularity. The molecular structure evolution characteristics of tectonic coal were analyzed by Raman spectrum, electron paramagnetic resonance spectroscopy and infrared spectrum. Raman spectroscopy analysis of tectonic coal can characterize the variation of secondary structural defects qualitatively. With the increase of tectonic coal, the structural defects of structural coal molecules change. The D peak area of brittle deformed coal increases gradually, and the D peak area of broken coal is larger than that of granular coal, while the D peak area of ductile deformed coal decreases gradually. Under the brittle deformation mechanism, the area of G peak increases rapidly with the increase of the tectonic coal R _ S _ O _ (max), and the growth rate of the fractured coal is larger. The G peak area of ductile deformed coal increases slowly. The reason for this phenomenon may be the degradation and condensation of the molecular structure of coal by tectonic stress. Through the electron paramagnetic resonance spectroscopy analysis of tectonic coal, it is found that the evolution law of different types of tectonic coal is different. The free radical concentration of broken coal decreased with the increase of metamorphic degree, that of pulverized coal decreased first and then increased, and the free radical concentration of minced coal showed the characteristics of N-type evolution. The infrared spectrum analysis of structural coal shows that with the increase of metamorphic deformation, the 鈪，

本文编号：1857825