A method for separating and recovering ultrafine particulate solid
material from a suspension or slurry of the solid material and a
hydrocarbon liquid by precipitation or flocculation of a heavy fraction
of the hydrocarbon liquid with an effective amount of a precipitation or
flocculation agent such that the precipitated heavy fraction encapsulates
the particulate solid material. The method further comprises coking the
precipitated heavy fraction and grinding the coked product to an
ultrafine size.