US 2004/0163491 A1 · Metalothermic reduction of refractory metal oxides

Abstract

High purity refractory metals, valve metals, refractory metal oxides, valve metal oxides, or alloys thereof suitable for a variety of electrical, optical and mill product/fabricated parts usages are produced from their respective oxides by metalothermic reduction of a solid or liquid form of such oxide using a reducing agent that establishes (after ignition) a highly exothermic reaction, the reaction preferably taking place in a continuously or step-wise moving oxide such as gravity fall with metal retrievable at the bottom and an oxide of the reducing agent being removable as a gas or in other convenient form and unreacted reducing agent derivatives being removable by leaching or like process.

Claims49

Dependent claims

A method of producing a powder by a continuous reduction reaction, wherein said powder is a refractory metal powder, a valve metal powder, a refractory metal alloy powder, a valve metal alloy, a refractory metal suboxide powder, or a valve metal suboxide powder, comprising:

a) providing a refractory or valve metal oxide as a continuous feed or segments of continuous feed;
b) contacting said refractory or valve metal oxide feed with a reducing agent to create a static or dynamically formed mixture;
c) reducing said refractory or valve metal oxide feed in a reaction zone by heating said mixture in a reaction vessel to create a highly exothermic reaction, said exothermic reaction being triggered by heating said mixture to an ignition temperature and/or by adding a further reagent or catalyst;
and
d) recovering a high surface area powder substantially free of impurities.

2 more elements

Dependencies are inferred from the claim text.

Metalothermic reduction of refractory metal oxides

Life of this patent

Metalothermic reduction of refractory metal oxides

Life of this patent

Abstract

Claims49