Method for producing cobalt powder

Abstract

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.

1 . A method of producing cobalt powder from a cobalt-containing material of an industrial intermediate including one or a mixture of two or more selected from cobalt and cobalt mixed sulfide, crude cobalt sulfate, cobalt oxide, cobalt hydroxide, cobalt carbonate, and cobalt powder, the method sequentially comprising:
 a mixing step of adding, to a solution containing a cobalt ammine sulfate complex in which a concentration of ammonium sulfate is in a range of 10 to 500 g/L and the cobalt-containing material is a cobalt supply source, cobalt powder having an average particle size of 0.1 to 5 μm as seed crystals in an amount of 1.5 times or more and 3.0 times or less an 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 seed crystals added to form a mixture slurry; and   a reduction and precipitation step of charging a reaction vessel with the mixture slurry, heating to a temperature of 150 to 200° C., blowing hydrogen gas into the mixture slurry while keeping the temperature, and maintaining a pressure of a gas phase part in the reaction vessel at a range of 1.0 to 4.0 MPa to reduce cobalt complex ions contained in the mixture slurry to form cobalt precipitate on a surface of the seed crystals.   
     
     
         2 - 4 . (canceled)