Date of Graduation
Statler College of Engineering and Mineral Resources
Mechanical and Aerospace Engineering
Mohindar S. Seehra
Since water is used extensively in coal preparation and cleaning, dewatering of coals is required prior to shipment to power plants. However, finer fractions of coals are difficult to dewater and consequently these fractions are stored in settling ponds, causing environmental problems and loss of a large fraction of coals. Thermal drying of coals is not an efficient process since hot air heats both coal and water. Mechanical processes for dewatering fine coal slurries have a limit for dewatering coal. Consequently, dewatering using selective heating by conventional microwaves at 2.45 GHz and IR heating at 10 14 Hz was undertaken as the primary focus of this project. The basis for this choice is the fact that theoretically water absorbs 120 times more microwave energy than coal. TGA and DSC were initially employed to determine the process of dewatering by thermal heating. Then using gram quantities of fine coal slurries, a conventional microwave oven was used to determine the efficiency of dewatering by selective microwave heating. X-ray diffraction of the 'before' and 'after' microwave treated coal slurry showed that the coal carbon is not affected by microwave treatment. Finally, a conventional microwave oven was modified to feed coal on a conveyor-belt to simulate a potential commercial unit.
Kalra, Aashish, "Dewatering of fine coal slurries by selective heating with microwaves" (2006). Graduate Theses, Dissertations, and Problem Reports. 1706.