Abstract: Apparatus and method for separating fly ash into its major constituents; namely, metal, carbon black, cenospheres and dust. The metal is separated by passing the fly ash through a magnetic field at least a part of which has an alternating polarity. The non-magnetic constituent is separated into conductive and dielectric constituents with a high tension separator and the conductive constituent, chiefly cenospheres, is then graded by size. The grading is effected by passing the non-magnetic, conductive fly ash constituent through a cross-flow of ionized air which suspends the cenospheres at different levels according to their weight and size. The apparatus and method has general utility, with obvious modifications, to the grading of particles other than cenospheres.