Spectral analysis is an important and unique advantageous method for the analysis of matter's structure and composition. Aiming to discuss the change characteristic and evolution mechanism of mineral structure of oil shale, kerogen and simecoke from oil shale pyrolysis under different temperature, the oil shale sample was obtained from Yaojie located in Gansu province, and the oil shale after pyrolysis experiments and acid washing were investigated and analyzed in detail with polarizing microscope, Fourier transform spectroscopy (FTIR), X-Ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that the mainly minerals of oil shale include quartz, clay and pyrite; kerogen is randomly distributed as mainly strip shaped or blocky in inorganic minerals. The metamorphic degree of kerogen is higher, and rich in aliphatic structures and aromatic structures. Experiments of oil shale pyrolysis(temperature: 300 similar to 1 000 degrees C, heating rate: 10 degrees C . min(-1)) with temperature increasing, the composition of mineral begins to dissolve, kaolinite turning into metakaolinite with dehydration at 300 degrees C, clay minerals such as kaolinite and montmorillonite completely turn into metakaolinite at 650 degrees C. The silica-alumina spinel and amorphous SiO2, generated from the decomposition of metakaolinite at 1 000 degrees C, and the amorphous SiO2, tends to react with iron mineral to form relative low melting point mixture on the semi-coke surfaces, such as FeO-Al2O3-SiO2. kerogen break down with increasing temperature, the infrared spectra intensity of C-H band of aliphatic and aromatic is reduced, while the intensity of C-C band aromatic is increased, and more carbonaceous residue as gully-shaped that remains in the mineral matrix after pyrolysis. These results are important for both the study of structure evolution of kerogen and minerals on the process of oil shale pyrolysis and will benefit for the subsequent processing and utilization of shale oil resource.
