US 2023/0405676 A1 · METHODS FOR THE PRODUCTION OF FINE METAL POWDERS

Abstract

Methods for the manufacture of fine metal powders from metal-containing ammonium compounds such as ammonium oxalate metal salts. The method includes decomposing particulates of the ammonium oxalate metal salt by heating to a decomposition temperature in the presence of a dilute hydrogen gas to decompose the ammonium oxalate compound, and form a fine metal powder by heating to a higher refining temperature to remove contaminants from the fine metal powder. The method may include the conversion of a non-oxalate metal compound to a hydrated metal oxalate and the dehydration of the hydrated metal oxalate before decomposition to the metal. The method is applicable to the production of a wide variety of metals of high purity and fine particle size.

Claims64

Dependent claims

A method for the production of fine metal powder, comprising the steps of:

heating a precursor powder comprising anhydrous ammonium oxalate metal salt particulates to a decomposition temperature while the precursor powder is under a decomposition gas, the decomposition gas and the decomposition temperature being sufficient to decompose the anhydrous ammonium oxalate metal salt particulates and form an intermediate metal powder and a gaseous by-product comprising ammonium oxalate and/or oxalic acid;
separating the gaseous by-product from the intermediate metal powder;
and
heating the intermediate metal powder to a refining temperature that is greater than the decomposition temperature and holding the intermediate metal powder at the refining temperature in the presence of a refining gas to remove contaminants in the intermediate metal powder and form a high purity fine metal powder.

1 more element

Dependencies are inferred from the claim text.

Methods for the production of fine metal powders

Life of this patent

Methods for the production of fine metal powders

Life of this patent

Abstract

Claims64