Lan Xin-zhe, Luo Wan-jiang, Song Yong-hui, Zhang Qiu-li, Zhou Jun
Guang Pu Xue Yu Guang Pu Fen Xi. 2016 Apr;36(4):1121-6.
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 sime-coke 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 withpolarizing 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: 300～1 000 ℃, heating rate: 10 ℃·min-1) with temperature increasing, the composition of mineral begins to dissolve, kaolinite turning into metakaolinite with dehydration at 300 ℃, clay minerals such as kaolinite and montmorillonite completely turn into metakaolinite at 650 ℃. The silica-alumina spinel and amorphous SiO2, generated from the decomposition of metakaolinite at 1 000 ℃, 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.
光谱分析是一种用于分析物质结构和组成的重要且独特的优势方法。为探讨油页岩在不同温度下热解产物中矿物结构的变化特征及演化机理，以甘肃窑街油页岩为研究对象，运用偏光显微镜、傅里叶变换红外光谱仪（FTIR）、X射线衍射仪（XRD）和扫描电子显微镜（SEM），对热解实验及酸洗后的油页岩进行了详细的研究与分析。结果表明，油页岩中的主要矿物有石英、黏土和黄铁矿；干酪根在无机矿物中呈无规则分布，主要为条带状或块状。干酪根变质程度较高，富含脂肪族结构和芳香族结构。油页岩热解实验（温度：300～1000℃，升温速率：10℃·min-1）表明，随着温度升高，矿物成分开始溶解，300℃时高岭石脱水转变为偏高岭石，650℃时高岭石和蒙脱石等黏土矿物完全转变为偏高岭石。1000℃时偏高岭石分解生成硅铝尖晶石和非晶态SiO2，非晶态SiO2倾向于与铁矿物反应在半焦表面形成相对低熔点的混合物，如FeO—Al2O3—SiO2。干酪根随温度升高发生分解，脂肪族和芳香族C—H键的红外光谱强度降低，而芳香族C—C键强度增加，热解后有更多沟状碳质残余物留在矿物基质中。这些结果对于研究油页岩热解过程中干酪根和矿物的结构演化具有重要意义，也将为后续页岩油资源的加工利用提供帮助。
