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 meta

Abstract: The invention provides a process for production of fine spherical particles of a carbonate or a hydroxide of nickel, cobalt or copper which comprises: dissolving a carbonate or a hydroxide of nickel, cobalt or copper having the general formula (I) M(CO3)x/2.(OH)y wherein M represents Ni, Co or Cu, and x and y are numerals satisfying the followings: 0≦x≦2, 0≦y≦2 and x+y=2, in aqueous ammonia, converting the resulting solution to a W/O emulsion containing droplets of the solution in a non-aqueous medium, and then removing volatile components including ammonia from within the droplets, thereby precipitating a basic carbonate or a hydroxide of a metal selected from nickel, cobalt and copperin the droplets.