METHOD FOR TREATMENT OF DUST RECOVERED FROM OFFGASSES IN METALLURGICAL PROCESSES

Method of treating dust precipitated from waste gases from metalurgical processes, especially dust precipitated from waste gases in connection with production of steel, in order to transfer the dust to a form in which it can be deposited without danger of environmental pollution and from which the valuable components of the dust can be revovered. According to the method the dust is treated in the following steps: a) continuous or approximately continuous supply of dust together with reducing agent and possible fluxes to a gastight covered electrothermic smelting furnace. b) smelting and selective reduction together with vola tilization of volatile metals in the smelting furnace. c) continuous or intermittent tapping of an inert slag phase and possibly a liquid metal phase from the smelting furnace. d) continuous removal from the smelting furnace of a gas phase containing chiefly CO-gas, metal fumes, sulphur, chlorides and fluorides together with entrained unreacted dust. e) possible selective condensation of one or more metals from the metal fumes in the waste gas from the smelting furnace f) controlled afterburning of oxydizable components in the waste gas g) removal of dust from the waste gas h) final purification and neutralization of the waste gas.