Structure Evolution And Deformation Mechanism Of Tectonically Deformed Coal

Based on the further research of macro-and microscopic deformation characteristicsand structural features of tectonically deformed coal, systematic classification, deformationsequence and corresponding evolution characteristics were discussed. In combination withthe tests of SEM, MIP, SMIP, LTNA, FT-IR and13C NMR, the evolution mechanism andcontrol factors of pore structure and molecular structure of tectonically deformed coal withthe difference of deformation sequences and deformation types were determined. Thefollowing conclusions have been made:(1) Tectonically deformed coal can be systematically divided into cataclasticstructural coal, schistose structural coal, mortar structural coal, granulitic structural coal,scaly structural coal, wrinkle structural coal and mylonitic structural coal,7types and19sub-types in total, based on the consideration of its structure and formation mechanism.Macro-and microscopic deformation characteristics and structural features were furtherdiscussed and the deformation evolution sequences, with the characteristics of multipleeffect combination and overall dislocation growth, were determined.(2) Deformation characteristics and classification of sliding surface of tectonicallydeformed coal were analyzed for the first time. According to the flatness and deformationcharacteristics, the sliding surface can be divided into types P, N, S, C, W and D,6typesand16sub-types in total. The effects of correlative and cross development and itsinfluence upon molecular structure evolution were discussed. Sliding surface transitedfrom type N to types S, C, P, W and D gradually, with the evolution of tectonicallydeformed coal deformation sequence.(3) The modes, mechanism and differences of effects on pore structure from differentstructural and deformation types were discussed systematically. The effects of differentdeformation types were different and presented a descending order of granulitic process,shear process, wrinkle process and cataclastic process. With the increase of structuraldeformation, the growth of corresponding stage pore volume was increased and thedeformation scale of coal was gradually reduced. Six types of pore structure, parallel type,reverse S type, angular type, M type, double S type and double curvature type were defined,as well as the pore volume incremental peak shape and their deformation originsignificance of10peak,1000peak,1W peak and10W peak. Pore throat developmentcharacteristics in tectonically deformed coal were determined by the SMIP. Tectonicallydeformed coal molecular structural features and their evolution trends with different structural deformation process were analyzed. Structural deformation is well indicated byparameters Z1and Z3. The increase of aromatization extent and aromatic fused ring wereintensively promoted by shear process, and the effect of ductile wrinkle process is weak,while the granulitic and mortar processes are unfavorable to aromatization.(4) New viewpoints of microscopic deformation effect, combination of microscopicdeformation structures and scale differentiation effect of tectonically deformed coal werepresented, which provides new methods for the analysis of microscopic deformation anddeformation mechanism of tectonically deformed coal. Based on the systematicallyresearch of deformation process signs and deformation conditions of tectonically deformedcoal,13effect types of structural deformation mechanism were presented, which reveal thedeformation mechanism of tectonically deformed coal essentially.