Filtration
AssigneeCoal Industry (Patents) Limited
InventorsDerek A. Parsons, James W. Clarke
Life of this patent
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Abstract
In the extraction of coal using a liquid solvent oil, filtration can be assisted by using a filter aid which is of coal origin. The filter aid is produced by high temperature processing of coal or an ash-rich coal-derived residue under conditions at which the ash component of the coal or residue does not fuse. A preferred starting material is filter cake from a coal extraction process.
Claims8
An improved method of filtering coal extract resulting from the extraction of coal with a liquid solvent, including the use of a filter aid, wherein the improvement comprises using as the filter aid the product of high temperature processing of filter coke from the coal extraction process to yield an effective filter aid, under conditions at which the ash component of the cake does not fuse and volatiles are removed therefrom.
Dependencies are inferred from the claim text.