Abstract: In the present invention, reaction is carried out between hydrogen gas and a metal halide vapor while supplying to the reacting region an active gas whose reactivity with the metal halide vapor is higher than the reactivity of the hydrogen gas with the metal halide vapor. The particular technique permits efficiently manufacturing a superfine magnetic metal powder of satisfactory properties while minimizing the amount of the hydrogen gas used.

Abstract: An improved process for producing superfines of metal is disclosed, which comprises reacting a metal halide containing gas with a reducing gas by causing to flow both the stream of a metal halide containing gas and the stream of a reducing gas concurrently but at different velocities so as to form an interfacial instability region in the reaction zone, and nuclei are formed in said instability region whereas said reaction zone is quenched (cooled) to inhibit the excessive growth of said nuclei. Application of a magnetic field to the reaction zone can enhance the degree of fineness and magnetic properties of the superfines thus produced.

Abstract: In a generally elongated reaction tube at an elevated temperature, a reducing gas stream is caused to flow along the axis of the reaction tube and a metal-halide gas stream diluted with an inert carrier gas is caused to flow in the same direction as but at a different velocity relative to the reducing gas stream. The two gas streams contact each other in a laminar manner and form an unstable interface region therebetween wherein the metal halide gas is reduced to form fine metal particles with uniform particle size.