Ultrafine spherical nickel powder for use as an electrode of laminated ceramic capacitors

Claim 1

A process for producing ultrafine spherical nickel powder for use in a laminate ceramics capacitor through a vapor phase chemical reaction between nickel chloride and hydrogen, said process comprising the steps of: i) charging a reaction vessel with said nickel chloride and evaporating said nickel chloride to generate vapor of nickel chloride; ii) mixing an inert gas with said vapor of the nickel chloride to form a mixture gas having a nickel chloride gas concentration of about 0.05 to about 0.3, and sending said mixture gas to a reaction zone; iii) bringing, in said reaction zone, said mixture gas into contact and mixing with hydrogen which is supplied from a nozzle at a temperature of about 1004° C. to about 1453° C. at a flow rate of said mixture gas which is decreased by keeping the amount of hydrogen supplied low, such that a flow rate ratio of said hydrogen to said mixture gas meets the condition of (H 2 /(NiCl 2 +inert gas)) ≦1, thereby causing said vapor phase chemical reaction; iv) generating ultrafine spherical nickel powder having a particle size of 0.2 to 3 μm by said chemical reaction; and v) cooling the generated ultrafine nickel powder together with the mixture gas and collecting said ultrafine nickel powder.