Microstructure Characteristics Of Coal-based Graphite

As an inorganic non-metallic mineral resource,graphite is widely used in aerospace,solar power generation,high-performance storage materials and other fields.It is also the main raw material for preparing graphene.In recent years,it has attracted more and more attention from countries around the world,and China is also actively developing and utilizing graphite resources.Graphite Industry Access Conditions will elevate it to the height of strategic resources.The "silicon age" will gradually enter the "carbon age".It is of great significance to focus on the microstructure characteristics and metallogenic mechanism of cryptocrystalline graphite in coal measures.In this paper,the coal measures cryptocrystalline graphite deposit and high metamorphic anthracite deposit in Hunan Lutang mining area are taken as the research objects.Three samples are taken from Lutang 5 mine and five samples from Lutang 6 mine respectively.By means of industrial analysis,XRD,SEM,TEM,Raman spectroscopy and other characterization means,Using the methods of mineralogy,crystallography,coal petrology and coal chemistry,the mineralogy characteristics of graphite with different metamorphic degrees and the changes of microstructure during the formation process of cryptocrystalline graphite in coal measures are studied,which provides important support for the subsequent development.The aphanitic graphite of coal measures in Hunan province comes from contact metamorphic deposit,and the graphite comes from coal metamorphism.Therefore,graphite and coal belong to the same layer and different ore phenomenon.The results of industrial analysis show that with the increase of graphite degree,the content of volatile matter decreases,and the content of fixed carbon increases.The results of XRD analysis show that the main component of each sample is graphite,accompanied by a small amount of clay minerals and mica.The samples with low metamorphic degree also contain quartz.With the decrease of the distance between coal measure graphite samples and magmatic intrusion,the degree of metamorphism increases,and the content of impurity minerals in the samples gradually decreases,and the ductility(La),stacking degree(Lc)and the number of stacking layers of basic structural units are decreased(N)They all increased gradually.The results of SEM and EDS show that with the increase of the modification degree,the graphite microcrystalline is more obvious,and the main chemical elements in the samples are carbon,and there are also oxygen,silicon,aluminum,iron and other elements.The transmission electron microscope results show that the higher the degree of modification,the more orderly the microcrystalline structure of graphite samples,the more obvious the edge.The hexagonal structure can be observed in the electron diffraction patterns,but there are both one Some spots with different intensities indicate that there are dislocation and atom missing in their lattice structure.Raman spectrum analysis results show that high metamorphism anthracite D peak sharp,peak strength is stronger,coal samples of aphanitic graphite quality peak shape similar,with the increase of metamorphic grade,said the disorder degree of D peak decreases,and the said order degree of the G peak increases gradually,the whole 6 series mine coal analysis results on the surface of graphite crystallization degree is higher than 5 ore sample.