The invention concerns a process for the spheroidisation, densification
and purification of powders through the combined action of plasma
processing, and ultra-sound treatment of the plasma-processed powder. The
ultra-sound treatment allows for the separation of the nanosized
condensed powder, referred to as `soot`, from the plasma melted and
partially vaporized powder. The process can also be used for the
synthesis of nanopowders through the partial vaporization of the feed
material, followed by the rapid condensation of the formed vapour cloud
giving rise to the formation of a fine aerosol of nanopowder. In the
latter case, the ultra-sound treatment step serves for the separation of
the formed nanopowder form the partially vaporized feed material.