Patent ID: 8013269

Claim:
A process for synthesizing a nanopowder comprising: a) feeding a reactant material into a plasma torch in which is generated a plasma gas stream having a temperature sufficiently high to yield a superheated vapour of said material; b) transporting said superheated vapour by means of said plasma gas stream into a quenching zone, wherein the quenching zone is a quenching chamber comprising a porous wall; c) injecting a cold quench gas into the plasma gas stream through a plurality of openings in the porous wall at a flow rate sufficient to form a laminar, renewable gaseous cold front and gradually displace the cold front toward the center of the plasma gas stream, thereby constricting the plasma gas stream; and d) forming a nanopowder from the superheated vapour at the interface between the renewable gaseous cold front and the plasma gas stream.