Manufacturing method for nickel powder

摘要

Provided is a manufacturing method by which, using industrially inexpensive hydrogen gas, coarse grains of a high-purity nickel powder can be produced from a nickel ammine sulfate complex solution, employing a fine nickel powder. This manufacturing method for forming a nickel powder from a nickel ammine sulfate complex solution is characterized in that the process steps indicated by (1) to (4) are carried out: (1) a seed crystal production step for mixing a nickel sulfate solution and hydrazine, and producing a nickel powder having an average particle diameter of 0.1-5 μm to serve as seed crystals; (2) a seed crystal addition step for adding the nickel powder obtained in (1) to a nickel ammine sulfate complex solution, and forming a mixed slurry; (3) a reduction step for blowing hydrogen gas into the mixed slurry obtained in the seed crystal addition step, and forming a reduced slurry that includes a nickel powder in which the nickel component in the mixed slurry has precipitated onto the seed crystals; and (4) a growth step for subjecting the reduced slurry obtained in the reduction step to solid-liquid separation to separate the nickel powder as the solid phase component, and, after recovery thereof, blowing hydrogen gas into a solution of a nickel ammine sulfate complex solution added to the nickel powder, and growing the nickel powder, to form a high-purity nickel powder.