# US 10,766,072 B2 · Method for producing high density nickel powder

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- Number: US 10,766,072 B2
- Document ID: US10766072B2
- Status: Granted
- Kind: B2
- Application number: 15/770,523
- Filed: 2016-10-25
- Published: 2019-02-21
- Granted: 2020-09-08
- Earliest claimed: 2015-10-26
- Assignees: Sumitomo Metal Mining Co., Ltd.
- Applicants: Sumitomo Metal Mining Co., Ltd.
- Inventors: Hideki Ohara; Yoshitomo Ozaki; Shin-ichi Heguri; Kazuyuki Takaishi; Osamu Ikeda; Tomoaki Yoneyama; Yohei Kudo
- Web page: https://patentgrep.com/patent/US10766072B2

## CPC

- B22F 9/22: using gaseous reductors
- B22F 9/26: using gaseous reductors
- B22F 1/05: Metallic powder characterised by the size or surface area of the particles
- B22F 9/24: starting from liquid metal compounds, e.g. solutions
- B22F 2301/15: Nickel or cobalt
- H01B 5/00: Non-insulated conductors or conductive bodies characterised by their form
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})

## Abstract

Provided is a method for producing high density nickel powder particularly having a median diameter of 100 to 160 μm by controlling a particle size of nickel powder. The method includes: performing an initial operation by charging a pressure vessel equipped with a stirrer with a nickel ammine complex solution containing nickel in the concentration of 5 to 75 g/L together with seed crystals in the amount of 5 to 200 g per liter of the solution, increasing the temperature of the solution, and performing a reduction reaction with hydrogen by blowing hydrogen gas into the pressure vessel, thereby obtaining the nickel contained in the nickel ammine complex solution as nickel powder; and thereafter, performing a specified operation A repeatedly at least once to obtain the nickel powder having the median diameter of 100 to 160 μm and a bulk density of 1 to 4.5 g/cm3.

## Claims

### Claim 1

A method of producing nickel powder, comprising:
performing an initial operation by charging a pressure vessel equipped with a stirrer with a nickel ammine complex solution containing nickel in a concentration of 5 to 75 g/L together with seed crystals in an amount of 5 g to 200 g per liter of the complex solution, increasing a temperature of the solution, and blowing hydrogen gas into the pressure vessel for performing a reduction reaction with hydrogen, thereby obtaining the nickel contained in the nickel ammine complex solution as nickel powder; and thereafter
performing an operation A repeatedly, the operation A including:
putting the obtained nickel powder in a cylinder filled with water;
stirring the nickel powder and the water in the cylinder;
allowing the cylinder to stand still in an upright position;
recovering from an upper portion of the cylinder a part of the obtained nickel powder; and
charging the pressure vessel equipped with the stirrer with the recovered nickel powder used as the seed crystals together with the nickel ammine complex solution in an amount of 5 g to 200 g per liter of the nickel ammine complex solution containing nickel in the concentration of 5 to 75 g/L, increasing a temperature of the solution, and performing the reduction reaction with hydrogen by blowing hydrogen gas into the pressure vessel for obtaining nickel powder,
to obtain the nickel powder having a median diameter of 100 μm or more and 160 μm or less, and having a bulk density of 1 to 4.5 g/cm3.

### Claim 2 (depends on 1)

The method of producing nickel powder according to claim 1, wherein the operation A is repeated four times or more and thus the reduction reaction is performed five times or more in total including the initial operation to obtain the nickel powder.