The Character Of Tectonic Coal Macromolecular Evolution In Hancheng Mining

Coal is a kind of complex molecules of organic rock, and very sensitive to the stress of the surrounding environment. Influenced on tectonic stress, coal bed formed different characteristics of tectonic coals. In comparison to primary coal, macro deformation characteristics and evolution of macromolecular structure for tectonic coal are different. In terms of macro deformation characteristics, from brittle deformed coal to ductile deformed coal, the preservation of primary structure is getting worse and worse, the particle size is getting smaller and smaller, and the components of macro coal are becoming more and more difficult to identify. At the same time, the forms of the frameworks for tectonic coal are becoming striation, step, squama, and corrugation structure from the bedding structure gradually. Compared with primary structure coal, the fragmented coal has a large fracture structure which is beneficial to the diffusion and seepage of coal bed methane, but the fractionation coal and mylonitized coal's fracture are seriously broken and the fracture structure can not be observed.In the process of metamorphism and deformation, tectonic coal molecular structure has some characteristics of evolution. The evolution of the macromolecular for tectonic coals was studied through the analysis of some parameters of the Raman, EPR and FTIR. By Raman spectrum, the degree of secondary structural defects was represented by Raman spectrum. With the R0,max becoming larger, the area of Peak D for brittle deformed coal becomes larger and larger; the amplitude of growth range for cataclastic coals is greater than fractionation coal. However, the area of Peak D for the ductile deformed coal became smaller and smaller. In the brittle deformation mechanism, with the R0,max becoming larger, the area of Peak G for brittle deformed coals becomes larger and larger; the rate of growth for cataclastic coals is bigger than fractionation coal; while the area of mylonitized coal grows slowly. The results may be the reason that the influence of tectonic stress on the macromolecular of tectonic coals is degradation and polycondensation.The characteristics of evolution of free radical concentration are varied for different types of tectonic coals by EPR spectrum. For cataclastic coals, it is getting lower and lower with the R_o,max becoming larger; for fractionation coals, it gets lower and then upper, and the change of it becomes circuitous for mylonitized coals.By the analSysis of FTIR, with the metamorphism and deformation greater, the hydrogen of ? in the aromaticity for tectonic coals gets more and more, and the degree of condensation of aromatic ring gets higher and higher, while the hydrogen of ? gets less and less, while the amounts of aliphatic hydrocarbon and oxygen containing functional groups decreases. Through the analysis of molecular structure of coal structure by using spectroscopy principle, the macromolecular structure of tectonic coals is well evolved.