煤岩变质变形作用的谱学研究

为了探讨不同变质程度煤在不同变形机制和变形强度影响下的结构成分演化,该文对淮北煤田经历不同变质变形作用的构造煤样品进行了傅里叶变换红外光谱(FTIR)和激光Raman光谱的测试和分析.FTIR显示,变质和变形作用对大分子结构的降解和缩聚过程有着不同程度的影响;激光Raman光谱显示,变形作用导致大分子结构中次生结构缺陷的产生,变质作用对次生结构缺陷和芳族总量也有一定的影响.综合研究表明:韧性变形将应力作用转换成应变能,对降解和缩聚产生明显的影响,而脆性变形将应力作用转换成热能,促进降解的进行,对缩聚作用的影响较小.低变质阶段煤岩以降解作用为主,高变质阶段则以缩聚作用为主.在变质变形作用的影响下,脱落的小分子优先补充嵌入大分子结构的次生结构缺陷中或残留的芳环缩聚形成芳族结构,从而提高煤岩结构的稳定性,且韧性变形比脆性变形更容易导致次生结构缺陷的形成.

Spectrum research on metamorphic and deformation of tectonically deformed coals

The structural and compositive evolution of tectonically deformed coals (TDCs) and their influencing factors were investigated and analyzed in detail through Fourier transform infrared spectroscopy (FTIR) and laser Raman spectra analysis. The TDC samples (0.7% < Ro,max <3.1%) were collected from Huaibei coalfield with different deformation mechanisms and intensity. The FTIR of TDCs shows that the metamorphism and the deformation affect the degradation and polycondensation process of macromolecular structure to different degree. The Raman spectra analysis indicates that secondary structure defects can be produced mainly by structural deformation, also the metamorphism influences the secondary structure defects and aromatic structure. Through comprehensive analysis, it was discussed that the ductile deformation could change to strain energy through the increase and accumulation of dislocation in molecular structure units of TDC, and it could make an obvious influence on degradation and polycondensation. While the brittle deformation could change to frictional heat energy and promote the metamorphism and degradation of TDC structure, but has less effect on polycondensation. Furthermore, degradation is the main reason for affecting the structural evolution of coal in lower metamorphic stage, and polycondensation is the most important controlling factor in higher metamorphic stage. Under metamorphism and deformation, the small molecules which break and fall off from the macromolecular tructure of TDC are preferentially replenished and embedded into the secondary structure defects or the residual aromatic rings were formed into aromatic structure by polycondensation. This process improved the stability of coal structure. It is easier for ductile deformation of coal to induce the secondary structure defects than brittle deformation.