Method for leaching nickel matte in the presence of added copper

摘要

The invention relates to a method for leaching pyrometallurgically produced, copper-containing sulfidic nickel matte. The nickel matte is first fed to an atmospheric leach step from which is obtained a nickel-bearing solution and a copper- and nickel-bearing leach residue, wherein the weight ratio of copper to nickel is not more than about 1. This is followed by adding a copper-containing solid matter into the leach residue and conducting the leach residue to pressure leaching. After the pressure leaching, there can be obtained a leach residue, which consists of copper sulfide precipitate relatively pure as regards iron and which also contains the precious metals of nickel matte.