Chakravorty, U: Coal Dust Scrubbing

Present day water spray based dust removal technologies do not effectively remove respirable submicron coal dust particles in the underground coal mines causing Coal worker‘s pneumoconiosis (CWP). This research studies the inherent electrostatic charges present in the airborne coal dust in order to develop efficient water spraying based dust removal technology where water drops charged using ionic compounds and surfactants would be used to capture the oppositely charged coal particles. Characterization studies performed using an Aerodynamic Particle Sizer and Aerosol Electrometer showed that airborne coal particles have a significant amount of positive charge with an average of 140 elementary units of charge. The capture efficiencies of the water drops evaluated were found to be higher than those predicted by previously determined mathematical models. It was predicted that apart from the effects of Brownian diffusion, interception and impaction, the effect of Coulombic attraction was responsible for enhanced coal dust removal.