Abstract: A method and apparatus for removing light hydrocarbons, such as heptane, from coal agglomerates includes an enclosed chamber having a substantially horizontal perforate surface therein. The coal agglomerates are introduced into a water bath within the chamber. The agglomerates are advanced over the surface while steam is substantially continuously introduced through the surface into the water bath. Steam heats the water and causes volatilization of the light hydrocarbons, which may be collected from the overhead of the chamber. The resulting agglomerates may be collected at the opposite end from the surface and subjected to final draining processes prior to transportation or use.

Abstract: A system for converting a coal slurry flowable through a pipeline to a coal water mixture capable of being rendered suitable for direct combustion in a boiler. The system includes a pipeline extending from a region adjacent to a mine or source of coal to a region adjacent to a boiler or furnace at which combustion is to take place. In the furnace region, the slurry from the pipeline is directed into a holding space, such as a pond, from which it is directed to a grinding apparatus. On the way to the grinding apparatus from the pond, a side stream of the slurry is directed through a dewatering apparatus where the concentration of the side stream is increased from 50-55 weight percent of solids to about 70-80 weight percent of solids. The outlet of the dewatering apparatus is directed back to the main flow of slurry from the pond, and the main flow enters the grinding apparatus where the slurry is ground to a particle size suitable for combustion, such as 70-80% weight percent of solids at -200 mesh.

Abstract: A process for preparing coal for use as a fuel. Forming a coal-water slurry having solid coal particles with a particle size not exceeding about 80 microns, transferring the coal-water slurry to a solid bowl centrifuge, and operating same to classify the ground coal-water slurry to provide a centrate containing solid particles with a particle size distribution of from about 5 microns to about 20 microns and a centrifuge cake of solids having a particle size distribution of from about 10 microns to about 80 microns. The classifer cake is reground and mixed with fresh feed to the solid bowl centrifuge for additional classification.