Abstract: 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 ti

Abstract: The present invention relates to a process for the separation of gold and silver from complex sulfide ores and concentrates which, in addition to the primary metals, contain constituents having an adverse effect on the separation of the noble metals, by heating the sulfide ore or concentrate at a temperature of 600.degree.-900.degree. C. and a sulfur pressure of 0.2-1 atm in order to bring the complex metal compounds to a suitable form for subsequent alkalic cyanide leaching, and by separating the gold- and silver-bearing cyanide solution from the undissolved residue.

Abstract: An apparatus for the vaporization of elemental sulfur by means of carrier gas, the apparatus comprising a first thermally insulated vessel for the melting of elemental sulfur, provided with a heating means, a stirrer and an inlet pipe for elemental sulfur, and at least one second vessel inside the first vessel and communicating vessel with it, and provided with heating means, a stirrer, means for feeding carrier gas and an outlet pipe for sulfur vapors, and optionally also provided with thermal insulation, for vaporizing the molten elemental sulfur flowing from the former vessel by means of carrier gas.