Method for producing uniform, fine boron-containing ceramic powders

US5194234A · kind A · utility

Assignee

• THE DOW CHEMICAL COMPANY · US

Inventors

• Alan W. Weimer · Niwot, US
• William G. Moore · Raleigh, US
• Raymond P. Roach · Midland, US

Key dates

• Filing date: Sep 12, 1991
• Grant date: Mar 16, 1993
• Expiry date: Sep 12, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/90
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Uniform, fine ceramic powder is prepared using an apparatus comprising (a) a cooled reactant transport member; (b) a reactor chamber; (c) a heating means; and (d) a cooling chamber. The reactant transport member comprises a wall defining a conduit that communicates with the reactor chamber, with a gas-flow space being defined along the perimeter of the transport member and in communication with the reactor chamber. The reactor chamber comprises a wall defining a reaction zone, and the heating means is associated with the reaction zone, and adapted for heating reactants in the reaction zone. The cooling chamber comprises a wall defining a cooling zone that communicates with the reactor chamber. In one embodiment the communication is by means of a cooling inlet, the diameter of the cooling zone being larger than the diameter of the cooling inlet. The temperatures of the reactant transport member, the reactor chamber, and the cooling chamber are independently controllable. Reactants can be fed through the reactant transport member into the reaction zone and reacted to form products, and the products then fed into the cooling zone to produce uniform, fine ceramic powders.