Separation of fine granular materials

This application concerns the separation of fine granular mixtures that may occur when the grains are suitably vibrated within fluid. In particular, the present invention provides a method of separating a particulate mixture comprising different particle types, comprising subjecting a supported particle bed comprising a fluid and said particulate mixture to a vibration thereby to effect separation of the particulate mixture into strata each of which is preferentially rich in substantially one particle type. Apparatus for effecting the above method also provided.