PURPOSE: To economically recover nickel from nickel sulfide in the form of an aq. soln. by treating the nickel sulfide in an aq. soln. contg. proper amounts of sulfuric acid and Cl ions by blowing air until a proper redox potential is attained.
CONSTITUTION: When metallic nickel is electrolytically refined with nickel matte as the anode, slime is produced on the anode. The slime or residue obtd. by removing part of elementary sulfur from the slime is added to water to prepare a slurry having about 200W300g/l concn. The slurry is filtered and ≥70g/l, preferably about 80W250g/l sulfuric acid and ≥10g/l, preferably about 35W50g/l ions are added to the resulting aq. soln. The Cl ions are added in the form of NaCl or the like. The aq. soln. is then heated and held at about 80W100°C and air or oxygen enriched air is blown until ≥550mV redox potential is attained. Thus, nickel is economically recovered from the nickel sulfide in the form of an aq. soln. without using gaseous chlorine.
OKABAYASHI MASAKATSU
SATO MASAHARU
TSUNEYAMA NOBUKI
NAKAGAWA TAKESHI
