Patent ID: 6379419
Filing Date: 2002-04-30
Classification: B01J,B22F

Abstract:
A method for the production of fine and ultrafine powders with a transferred arc plasma system, the method comprising the steps of:providing a material to be vaporized or decomposed in a plasma reactor; supplying a plasma torch feed gas; striking an arc between the material and an electrode to generate a plasma having a temperature sufficiently high to vaporize or decompose the material and form a vapor thereof; injecting a diluting gas that is heated to a temperature of at least about 1000 K. into the plasma reactor, the diluting gas being injected at a port that is physically separated from the plasma torch feed gas; transporting the vapor, by means of the plasma gas and diluting gas, into a quench tube wherein the vapor is condensed and powder formation occurs, the quench tube comprising: a first section for indirectly cooling or heating the vapor, to cause particle growth and crystallization in the first section; and a second section coupled to the first section for directly cooling the particles present therein; and collecting the cooled particles in a collection unit.