FOERFARANDE FOER AVLAEGSNING AV FOERORENINGAR FRAON SULFIDISKA OCH METALLISERADE STENSMAELTOR AV KOPPAR OCH ANORDNING FOER UTFOERANDE AV FOERFARANDET

A process for the removal of impurities from sulphidic and metallized molten copper mattes, in which in preliminary smelting of the crude metal molten sulphide and molten arsenide-antimonide phases are produced, whereby (a) the molten arsenide-antimonide matte is treated with elemental sulphur vapor to produce molten sulphide and molten arsenide phases in equilibrium with each other, that after this the conjugate melt system is sulphurated continuously under reduced pressure in order to volatilize arsenic, antimony, bismuth, lead and tin, or (b) the conjugate molten phases in equilibrium with each other are separated from each other, the thus separated arsenide matte is sulphurated further in a solid state and advantageously using elemental sulphur vapor at high partial pressure in order to volatilize arsenic, antimony, bismuth, selenium and tellurium from the matte as sulphides, and the separated molten sulphide phase is sulphurated under reduced pressure to volatilize arsenic, antimony, bismuth, lead and tin from the melt.