A method for manufacturing nickel powder whereby a reduction in production efficiency due to abrasion of a flash vessel connected to a pressurized container can be suppressed when nickel powder is generated using the pressurized container and subsequently recovered. The method for manufacturing nickel powder comprises charging a pressurized container with a nickel sulfate ammine complex solution and seed crystals, adding hydrogen gas to the pressurized container, and reducing the nickel included in the nickel sulfate ammine complex solution, wherein, when a nickel powder slurry obtained in the pressurized container is extracted to a flash vessel connected to the pressurized container, the slurry is extracted to the flash vessel while the supply rate of the nickel ammine complex solution to the pressurized container and/or the extraction rate of the nickel slurry from the pressurized container is controlled so the liquid level in the pressurized container is in a fixed range.

Provided is a method for producing coarse particles of so-called high purity nickel powder containing a small amount of impurities and particularly having a low sulfur content from a nickel ammine sulfate complex solution using fine nickel powder. The method for producing nickel powder from a nickel sulfate solution includes the treatment steps of: (1) a hydroxylation step of producing a precipitate of nickel hydroxide; (2) a complexing step of forming a mixture slurry containing a nickel ammine sulfate complex solution, seed crystals, and the nickel hydroxide; (3) a reduction step of forming a reduced slurry containing the nickel powder formed by precipitation of a nickel component on the seed crystals: and (4) a solid-liquid separation step of subjecting the reduced slurry formed in the reduction step (3) to solid-liquid separation to separately recover the nickel powder and a post-reduction solution.

Provided is a method for producing coarse particles of so-called high purity nickel powder containing a small amount of impurities and particularly having a low sulfur content from a nickel ammine sulfate complex solution using fine nickel powder. The method for producing nickel powder from a nickel sulfate solution includes the treatment steps of: (1) a hydroxylation step of producing a precipitate of nickel hydroxide; (2) a complexing step of forming a mixture slurry containing a nickel ammine sulfate complex solution, seed crystals, and the nickel hydroxide; (3) a reduction step of forming a reduced slurry containing the nickel powder formed by precipitation of a nickel component on the seed crystals: and (4) a solid-liquid separation step of subjecting the reduced slurry formed in the reduction step (3) to solid-liquid separation to separately recover the nickel powder and a post-reduction solution.

Provided is a method for producing coarse particles of so-called high purity nickel powder containing a small amount of impurities and particularly having a low sulfur content from a nickel ammine sulfate complex solution using fine nickel powder. The method for producing nickel powder from a nickel sulfate solution includes the treatment steps of: (1) a hydroxylation step of producing a precipitate of nickel hydroxide; (2) a complexing step of forming a mixture slurry containing a nickel ammine sulfate complex solution, seed crystals, and the nickel hydroxide; (3) a reduction step of forming a reduced slurry containing the nickel powder formed by precipitation of a nickel component on the seed crystals: and (4) a solid-liquid separation step of subjecting the reduced slurry formed in the reduction step (3) to solid-liquid separation to separately recover the nickel powder and a post-reduction solution.

Embodiments of the present disclosure provide for a continuous-flow reactor, methods of making metal nano-alloys, and metal nano-alloys.

Embodiments of the present disclosure provide for a continuous-flow reactor, methods of making metal nano-alloys, and metal nano-alloys.

A method for producing a FeCo alloy powder suitable for an antenna includes steps, wherein when introducing an oxidizing agent into an aqueous solution containing Fe ions and Co ions to generate crystal nuclei and cause precipitation and growth of a precursor having Fe and Co as components, Co in an amount corresponding to 40% or more of the total amount of Co used for the precipitation reaction is added to the aqueous solution at a time after the start of the crystal nuclei generation and before the end of the precipitation reaction to obtain the precursor. Then, a dried product of the precursor is reduced to obtain a FeCo alloy powder. This FeCo alloy powder has a mean particle size of 100 nm or less, a coercive force Hc of 52.0 to 78.0 kA/m, and a saturation magnetization ss of 160 Am.sup.2/kg or higher.

A method for producing a FeCo alloy powder suitable for an antenna includes steps, wherein when introducing an oxidizing agent into an aqueous solution containing Fe ions and Co ions to generate crystal nuclei and cause precipitation and growth of a precursor having Fe and Co as components, Co in an amount corresponding to 40% or more of the total amount of Co used for the precipitation reaction is added to the aqueous solution at a time after the start of the crystal nuclei generation and before the end of the precipitation reaction to obtain the precursor. Then, a dried product of the precursor is reduced to obtain a FeCo alloy powder. This FeCo alloy powder has a mean particle size of 100 nm or less, a coercive force Hc of 52.0 to 78.0 kA/m, and a saturation magnetization ss of 160 Am.sup.2/kg or higher.

Provided is a method for producing cobalt powder with high reaction efficiency by controlling the amount of added seed crystals when cobalt powder is produced from a solution containing a cobalt ammine sulfate complex. The method sequentially includes: a mixing step of adding, to the solution containing a cobalt ammine sulfate complex, cobalt powder as seed crystals in an amount of 1.5 times or more and 3.0 times or less the amount of cobalt contained in the solution and then adding a dispersant in an amount of 1.5% by weight to 3.0% by weight of the added seed crystals to form a mixture slurry; and a reduction and precipitation step of charging a reaction vessel with the mixture slurry and then blowing hydrogen gas into the mixture slurry to reduce cobalt complex ions contained in the mixture slurry to form cobalt precipitate on the surface of the seed crystals.

Provided is a method for producing cobalt powder with high reaction efficiency by controlling the amount of added seed crystals when cobalt powder is produced from a solution containing a cobalt ammine sulfate complex. The method sequentially includes: a mixing step of adding, to the solution containing a cobalt ammine sulfate complex, cobalt powder as seed crystals in an amount of 1.5 times or more and 3.0 times or less the amount of cobalt contained in the solution and then adding a dispersant in an amount of 1.5% by weight to 3.0% by weight of the added seed crystals to form a mixture slurry; and a reduction and precipitation step of charging a reaction vessel with the mixture slurry and then blowing hydrogen gas into the mixture slurry to reduce cobalt complex ions contained in the mixture slurry to form cobalt precipitate on the surface of the seed crystals.