Mineralogy monitoring and characterization of the springbok coalfields coal

In this study, the Springbok coalfields coal samples were collected and subjected to different temperatures ranging between 700-900 °C under nitrogen atmosphere in order to investigate the effect of combustion on the mineral changes. The proximate analysis, calorific value of both raw samples and combusted were carried out. Characterisation and mineralogy of samples (1426, 1427, 1428 and 1429) carried out by X-ray diffraction, X-ray fluorescence, FTIR and SEM incorporated with EDS. Calorific value (CV) ranging from 14.7 MJ/Kg to maximum 22.4 MJ/Kg, with 1427 having the highest CV and 1428 having the lowest CV. Inherent moisture, volatile matter, ash content and fixed carbon of 1427 after proximate analysis were 2.4%, 29%, 32.1% and 22.4 MJ/Kg respectively. The XRF and EDS results reveals on the raw samples considerable amount of impurities such as Si, Al, Fe and S while XRD denote the presence of SiO₂ and Al₂O₃ in the form of quartz and Kaolinite associated with Fe₂O₃ and FeS₂. The SEM micrograph shows that the carbon form layered structure like while the IR spectra of coals revealed C=C stretching at (1529 - 1715 cm-1) and O-H bonds on 700 and 900 cm^-1. The product from the combustion show considerable changes in the mineralogical structure with the formation of beta cristobalite and mullite which may have a negative effect on the calorific value of coal.