PURPOSE: To produce ultrafine metallic particles by adding fine metallic particles to a soln. contg. a surfactant, blowing a gaseous hydrogen-oxygen mixture into the soln., sticking the metallic particles to the resulting bubbles and bringing the bubbles into contact with a hot wire to burn the bubbles and to evaporate the metallic particles.

CONSTITUTION: Metallic particles to be made ultrafine are added to a soln. contg. a surfactant, they are mixed and charged into a vessel 4 and a gaseous hydrogen-oxygen mixture is blown from the bottom of the vessel 4 in the form of bubbles 3. The metallic particles are stuck to the bubbles 3 and the bubbles 3 are floated to the surface of the soln. and brought into contact with a hot wire 6 to burn and vanish the bubbles and to melt and evaporate the stuck metallic particles. The resulting vapor is cooled by sticking to a water cooled magnetic rotating drum 7 to produce ultrafine metallic particles.