Method and apparatus for separating particulate materials of different specific gravities

Abstract From the Canadian patent

Abstract of the Disclosure A movably mounted receptacle having perforations therein with hollow spigots connected to the receptacle in registry with the perforations and projecting substantially downwardly therefrom, these spigots being moved through a bed of the particulate material in a receiver while particles of the material move through the spigots. The spigots discharge the particles moving therethrough into the bed and agitate the bed during movement therethrough. A fluid medium is directed in the materials in the receptacle this, medium going through the spigots with the material particles and overflowing from the receiver, carrying lighter particles with it while heavier particles …