Structural changes due to coalification and oxidation influence the coal quality, geochemically and petrologically. Understanding of the coal structures helps to predict the behaviour of coal at various processes. The...Structural changes due to coalification and oxidation influence the coal quality, geochemically and petrologically. Understanding of the coal structures helps to predict the behaviour of coal at various processes. The objective of this paper is to study the changes in organic structure and mineral phase transformation during combustion. Different density fractions were generated and then heated at different temperatures from 200 to 1000 ℃. Petrography, Fourier transform infrared spectroscopy （FTIR） and X-ray diffraction （XRD） were carried out on all the density fractions aimed to accomplish this objective. Here, through petrography, it was observed that the vitrinite and liptinite macerals disappear at higher temperature while porous inertinite is seen. The inertinite structure is exposed which is assumed by the presence of -OH and C-O-C stretches with the aromatic nucleus （CH） and three to four adjacent H from FTIR spectra. Moreover, it can be concluded that aliphatic groups get collapsed at high temperature. In case of inorganic matter, through XRD and FTIR, it is also revealed that with increasing temperature, clay minerals converted into elemental oxides. Hence, this study is suggesting that the structures of coal are altered by the degree of contact metamorphism.展开更多
Coal petrology provides significant inputs for the industrial utilisation of coal and for broad understanding the coal formation and diagenesis. The present paper entails the results of the investigations carded out o...Coal petrology provides significant inputs for the industrial utilisation of coal and for broad understanding the coal formation and diagenesis. The present paper entails the results of the investigations carded out on the selected coal samples, from Ib valley and Umaria coalfield, using scanning electron microscope （SEM） and X-ray diffraction （XRD） to study the surface microstructures and minerals present in them and the relationship of the finely dispersed mineral matter with the organic constituents. This would further help in evaluating the distribution and chemical character of the mineral matter occurring within the maceral types. Ib valley and Umaria coals are typical Indian （Lower Gondwana） non-coking coals and only scanty data is available on SEM study of these coals. Under SEM examination, it manifests that, the mineral matters of these coal occur as deep intergrowth, massive impregnation, superficial mounting, filling and depletion of micropores, mechanical cavity filling and fusinitic cavity filling.展开更多
文摘Structural changes due to coalification and oxidation influence the coal quality, geochemically and petrologically. Understanding of the coal structures helps to predict the behaviour of coal at various processes. The objective of this paper is to study the changes in organic structure and mineral phase transformation during combustion. Different density fractions were generated and then heated at different temperatures from 200 to 1000 ℃. Petrography, Fourier transform infrared spectroscopy （FTIR） and X-ray diffraction （XRD） were carried out on all the density fractions aimed to accomplish this objective. Here, through petrography, it was observed that the vitrinite and liptinite macerals disappear at higher temperature while porous inertinite is seen. The inertinite structure is exposed which is assumed by the presence of -OH and C-O-C stretches with the aromatic nucleus （CH） and three to four adjacent H from FTIR spectra. Moreover, it can be concluded that aliphatic groups get collapsed at high temperature. In case of inorganic matter, through XRD and FTIR, it is also revealed that with increasing temperature, clay minerals converted into elemental oxides. Hence, this study is suggesting that the structures of coal are altered by the degree of contact metamorphism.
文摘Coal petrology provides significant inputs for the industrial utilisation of coal and for broad understanding the coal formation and diagenesis. The present paper entails the results of the investigations carded out on the selected coal samples, from Ib valley and Umaria coalfield, using scanning electron microscope （SEM） and X-ray diffraction （XRD） to study the surface microstructures and minerals present in them and the relationship of the finely dispersed mineral matter with the organic constituents. This would further help in evaluating the distribution and chemical character of the mineral matter occurring within the maceral types. Ib valley and Umaria coals are typical Indian （Lower Gondwana） non-coking coals and only scanty data is available on SEM study of these coals. Under SEM examination, it manifests that, the mineral matters of these coal occur as deep intergrowth, massive impregnation, superficial mounting, filling and depletion of micropores, mechanical cavity filling and fusinitic cavity filling.
