Process for cleaning fine coal

A process for the wet concentration and cleaning of fine coal comprising the steps of introducing a feed slurry of coal and associated contaminant particles having an average particle size predominantly less than about 6 mm to a hydrocyclone separator having an ascending vortex finder and an underflow discharge port, regulating the discharge from the discharge port to provide controlled discharge at said port of a coal particle fraction having a particle size greater than about 0.1 mm while discarding substantially all the fine silt of less than 0.1 mm reporting to the ascending vortex finder, introducing the controlled discharge of greater particle size to the upper end of a dense medium separation vessel having a manifold for injecting water at an intermediate level and having a variable orifice at its lower end for releasing the heavier particles therefrom, controlling the effective size of the orifice at the lower end for maintaining a fluidized bed of heavier than coal contaminant particles extending upwardly from the lower end of the vessel whereby heavier contaminant particles in the feed slurry may enter and pass downward for removal while the portion of the feed slurry containing only the lighter particles of coal and very small heavier contaminant will be suspended above said fluidized bed for selective recovery and introducing the latter slurry to a concentrating and dewatering screen to release water and particles having a size of the order of 0.25 mm or less and thereby recovering the cleaned and dewatered coal fraction of the feed slurry.