Method for producing fine powder of metallic nickel comprised of fine spherical particles
US6592645B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2001 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Jul 20, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2999/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process for the production of fine powder of metallic nickel which comprises a first step of dissolving nickel carbonate and/or nickel hydroxide in aqueous ammonia or in an aqueous solution of ammonia and at least one selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, a carbonate of an alkali metal and a hydrogencarbonate of an alkali metal to prepare an aqueous solution of a nickel salt; converting the aqueous solution of a nickel salt to a W/O emulsion, and then removing volatile components including ammonia from the droplets to form precipitates of nickel carbonate in the droplets, thereby providing fine spherical particles of nickel carbonate; and a second step of heating the particles of nickel carbonate in the presence of a fusion preventive agent that is a compound of at least one element selected from the group consisting of alkaline earth elements, aluminum, silicon and rare earth elements in an atmosphere of hydrogen, thereby reducing the nickel carbonate to metallic nickel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.