Method for producing high density nickel powder

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 operation A repeatedly at least once, the operation A being performed by:
• separating the obtained nickel powder according to a density to recover nickel powder having a small density;
• and
• weighing the recovered nickel powder having a small density 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, charging the pressure vessel equipped with the stirrer with the weighed nickel powder used as seed crystals together with the nickel ammine complex solution, 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.