Thermal and Ftir Study of Water Immersed Coal of Raniganj Coalfield, West Bengal

This study investigates the impact of water immersion on the physicochemical properties of coal from two mines within the Raniganj coalfield (RCF). The first sample is taken from Chora Colliery 10 Pit, which is an underground coal mine, and another sample is taken from Dahibadi Basantimata Colliery, which is an open-cast coal mine. Coal samples were subjected to proximate analysis, differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR). After this, these coal samples were immersed in water in the ratio of 1:10 in the lab environment. These coal samples were taken out after 15, 30, 90, and 180 days and studied by the above method. Proximate analysis revealed a significant increase (30-50%) in moisture and volatile matter content in water-immersed coal compared to raw coal. DSC analysis showed a decrease in ignition temperature of water-immersed coal samples that may increase the risk of spontaneous combustion. FTIR spectroscopy showed that the relative concentration of organic compounds increased in water-immersed coal, which also may favour spontaneous combustion. Volatile matter analysis also confirms the finding of FTIR analysis. These results collectively demonstrate that water immersion significantly enhances the propensity for spontaneous combustion in coal by increasing moisture, volatile matter, and the concentration of reactive organic compounds while lowering the ignition temperature.