Development of the Nickel-Refining Production at Norilsk Nickel Harjavalta Oy in GMK Norilsk Nickel

As a result of the innovative solutions found due to the joint efforts of Russian and Finnish researchers, the recovery of nonferrous and precious metals in Norilsk Nickel Harjavalta was significantly increased (%): the recovery of Ni was increased to 98.7; that of Cu, to 99.5; Pt, to 99.6; and Pd to 99.6. Simultaneously, a copper cake (one of the main commercial products) of an improved composition, namely, (%) 57–62 Cu, <3 Ni, 8–11 Fe, was produced. The arsenic content in the copper cake was decreased from 1.5–2 to 0.15–0.3%. The largest projects are as follows: stage-by stage implementation of a matte-free technology with simultaneous modification of the matte line for processing converter matte; the development of a jarosite technology of iron deposition from a nickel solution, which decreased the irreversible losses of nonferrous and precious metals with a waste iron cake as much as possible (the losses of nickel and cobalt were decreased by 11 times; those of copper, by 23 times; platinum, by 16%; palladium, by 10%; rhodium, by 9%; gold, by 12%); and the building and introduction of carbonate processing, which allowed the production of nickel cathodes to be increased. As a result of the measures taken to redistribute raw materials, the mattes of slag-cleaning furnaces, which contained 35–40% Fe, were moved to KGMK. This integration solution led to a significant synergy effect in Nornickel. One of the key factors of the economic efficiency of the matte-free technology was a decrease in the specific consumption of the main reagents (oxygen, air, sulfuric acid) and the energy resources used for the manufacture of nickel products. As a result, the transaction costs were decreased by ~3.5 mln dollars per year.