Process for cleaning and dewatering fine coal
AssigneeLinatex Corporation of America
InventorRobert E. Ennis
Life of this patent
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Abstract
A wet mechanical process is described for cleaning, upgrading and dewatering fine coal. The process provides for forming an aqueous feed slurry of fine coal and its associated contaminant particles wherein all particles have a particle portion size of less than about 6 mm. ranging to zero. The feed slurry is separated into coal slurry and refuse slurry portions in a spiral gravity concentrator by removing contaminants having a particle size greater than about 0.15 mm. The concentrated coal slurry is then fed to a hydrocyclone separator where all of the ultra-fine silt material having a particle size of less than 0.15 mm. is removed and the coal particle fraction 6 mm. to 0.15 mm. is accumulated and thoroughly dewatered.
Claims12
A process for the wet concentration of fine coal comprising the steps of providing an aqueous feed slurry of coal and associated contaminate particles, the solids in said feed slurry having a particle size of less than about 10 mm.;
- feeding at least the portion of said slurry having contaminate particles greater than 0.1 mm. through a spiral gravity concentrator so that as the slurry flows along the spiral under gravity the heavier contaminates having a particle size greater than about 0.1 mm. concentrate in a band separate from at least the portion of the coal slurry having contaminate particles greater than 0.1 mm., and (c);
- feeding to a hydrocyclone separator at least the portion of the coal slurry containing the coal and the associated contaminate particles of less than 0.1 mm., said hydrocyclone having ascending vortex finder and an underflow discharge port;
- regulating the discharge from the discharge port to provide controlled accumulation at said port of a coal particle fraction having a particle size greater than about 0.1 mm. while discarding substantially all contaminate particles of less than 0.1 mm. reporting to the ascending vortex finder, discharging the coal fraction accumulated at the discharge port at a substantially higher solids concentration than the slurry entering said hydrocyclone separator and dewatering the coal fraction slurry treated in both said spiral and hydrocyclone separators sufficiently to permit stockpiling of the cleaned coal fraction.
Dependencies are inferred from the claim text.