PRODUCTION METHOD OF METAL FINE POWDER

摘要

PROBLEM TO BE SOLVED: To provide a production method of a metal fine powder which allows sufficient increase of the ratio of the trivalent titanium ion in regenerating a reductant aqueous solution and repeated production of a microscopic metal fine powder.SOLUTION: A production method of a metal fine powder includes the steps of: precipitating a metal ion generated by electrolytic dissociation ionization in an aqueous solution of a water-soluble metal compound as a metal fine powder by the reduction based on oxidation of the trivalent titanium ion to the tetravalent titanium ion; separating the metal fine powder from the aqueous solution; and regenerating the tetravalent titanium ion in the aqueous solution to the trivalent titanium ion, and the trivalent titanium ion regeneration step includes the steps of: reducing metal ions other than titanium remaining in the aqueous solution preferentially at a first voltage; and reducing the tetravalent titanium to the trivalent titanium ion at a second voltage higher than the first voltage.