Method for producing ultrafine tungsten powder
AssigneeShow A Denko K.K.
InventorsKazumi Naito, Shoji Yabe
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Abstract
A method for finely powdering tungsten powder, which includes: a process for classifying a material tungsten powder into a fine powder having a relatively small average particle diameter and a coarse powder having a relatively large average particle diameter; an oxidation process for forming an oxide film on the particle surface of the coarse powder; and an alkali treatment process for removing the oxide film formed in the oxidation process and a natural oxide film formed on the fine powder with an alkali aqueous solution. Also disclosed is a method for producing ultrafine tungsten powder, which includes obtaining tungsten powder having an average particle diameter of 0.04 to 0.4 μm and a BET specific surface area of 5 to 15 m2/g by the above method for finely powdering.
Claims15
A method for finely powdering tungsten powder, comprising:
- a classification process for classifying a material tungsten powder into a fine powder having a relatively small average particle diameter and a coarse powder having a relatively large average particle diameter;
- an oxidation process for forming an oxide film on the particle surface of the coarse powder having a relatively large average particle diameter;
- and
- an alkali treatment process for removing the oxide film formed in the oxidation process and a natural oxide film formed on the fine powder with an alkali aqueous solution.
A method for finely powdering tungsten powder, comprising:
- a classification process, repeating once or more of a step of classifying a material tungsten powder into a fine powder having a relatively small average particle diameter and a coarse powder having a relatively large average particle diameter;
- an oxidation process for forming an oxide film on the particle surface of the coarse powder obtained by the classification;
- and
- an alkali treatment process for removing the oxide film formed in the oxidation process and a natural oxide film formed on the fine powder, which is obtained in the above multiple steps of classification, with an alkali aqueous solution.
Dependencies are inferred from the claim text.