Method of producing metal powder
AssigneeTokuyama Corporation
InventorsHiroyuki ODA, Naoto MOCHIZUKI
Life of this patent
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Abstract
A metal powder having a BET specific surface area of 5 to 250 m2/g is obtained by contacting and mixing together a gas of a metal chloride (metal source gas) and a reducing gas (e.g., hydrogen gas) that have been separately heated so as to instantaneously form fine metal particles based on the gas phase reduction reaction thereof, and collecting the fine metal particles from the gas stream after the reaction.
Claims10
A method of producing a metal powder including:
- a preparatory step of providing a metal chloride gas and a reducing gas;
- a gas phase reduction step in which said metal chloride gas and said reducing gas are contacted and mixed together so as to undergo a gas phase reduction reaction to form metal particles in a gas stream thereof;
- and
- a collection step of obtaining a metal powder by collecting the metal particles from the gas stream after said gas phase reduction reaction;
- wherein,
- in said preparatory step, said metal chloride gas and said reducing gas are heated separately from each other, said metal chloride gas being maintained at a temperature lower than a thermal decomposition temperature of said metal chloride;
- in said gas phase reduction step, said metal chloride gas and said reducing gas are contacted together so that the temperature of the mixed gas of said metal chloride gas and said reducing gas becomes higher than a temperature at which said gas phase reduction reaction takes place;
- and
- the metal powder obtained through said collection step has a BET specific surface area of 5 to 250 m2/g.
A silicon powder having a BET specific surface area in a range of 5 to 250 m2/g and an oxide layer of an apparent thickness of less than 5 nm as measured after having been left to stand in the air of normal temperature, normal pressure and a humidity of 50% for 24 hours.
Dependencies are inferred from the claim text.