Characterization of Coal Combustion Residues Using Transmission Electron Microscopy Technique

Abstract

Indian coal-based thermal power stations produces huge amount of coal combustion residues. Proper disposal, management and utilization of these ashes have always been a challenge before the thermal power plant management people. In order to find out the potential use of coal combustion residues one need to explore and look deeply into its various characteristic properties. In the present study the coal combustion residue samples from thermal power station of eastern India were used for characterizing ashes on the basis of Transmission Electron Microscopy technique. The study of the micrographs of Transmission Electron Microscopy showed that the coal combustion residue samples consisted of all the three viz. crystalline, polycrystalline and amorphous phases. The coal combustion residue samples were found to consist of single crystal, single crystal with hexagonal structure, polycrystalline substances and closed packed hexagonal structure. Concentric circles as seen in the diffraction pattern show the presence of polycrystalline substances in the samples. Presence of plerosphere in the coal combustion residue samples can also be seen from some SEM micrographs as well as one of TEM images. XRD studies show the presence of various crystalline substances present in the coal combustion residues. The study shows that the CCR samples are typically formed of Si-Al-Fe system with traces of sodium, potassium, calcium, magnesium, sulphur and titanium.