Plasma production of ultra-fine ceramic carbides
AssigneeIdaho Research Foundation, Inc.
InventorsPatrick R. Taylor, Shahid A. Pirzada
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Abstract
An apparatus and method for the synthesis of ultra-free (submicron) ceramic carbides in a thermal plasma torch reactor using primarily silica, boron oxide, titanium dioxide or other oxides as metal sources and methane as a reductant. A plasma torch operated with both argon and helium as plasma gases and having methane as a primary carrier gas is connected to the plasma reactor for providing the heat necessary to carry out the reaction. A collection chamber with both interior and exterior cooling is connected to the reactor for quenching of the reactants. Cooling is provided to the torch, the reactor and the collection using coils, baffles and jackets.
Claims12
A method of producing ultra-fine ceramic carbides in a reactor using a plasma torch for providing heat to said reactor, said method comprising the steps of:
- (a) injecting materials for reaction at points around a periphery of said torch into a first reaction temperature zone with a temperature above 3000.degree. kelvin., said first reaction temperature zone including a first means for controlling temperatures;
- (b) passing said reactants from said first zone to a second zone with a temperature between 2000.degree. kelvin and 3000.degree. kelvin, said second zone including a second means for controlling temperatures;
- and
- (c) causing said reactants to enter a third zone for rapid quenching, said third zone having a temperature less than 2000.degree. kelvin, said third zone including a third means for controlling temperatures.
A method of producing ultra-fine ceramic carbides, said method comprising the steps of:
- (a) starting a plasma torch on a mixture of argon and helium gases, said torch being attached to a power supply and to a front of a reaction chamber of a reactor;
- (b) preheating said reactor to a predetermined temperature by means of said plasma torch, said argon and helium gases being independently controlled to adjust said torch temperature to said predetermined temperature;
- (c) carrying reactants to said reaction chamber by a carrier gas comprising at least one member selected from the group consisting of methane, argon and mixtures thereof;
- and
- (d) causing said reactants to enter said reaction chamber, said reaction chamber having a first reaction temperature zone including a first means for controlling temperatures, a second reaction temperature zone including a second means for controlling temperatures, and a third reaction temperature zone including a third means for controlling temperatures.
Dependencies are inferred from the claim text.