Process and installation for treating of flue dusts from electric steelworks

摘要

The present invention relates to a process and facility for processing the electric steelworks dusts and zinc-bearing, high-iron, oxidized materials in a low-frequency induction furnace of coreless type, resulting in:reduction of contained iron oxides to cast iron,concentration of non-ferrous metal oxides in fumes recovered from the process, andformation of slag suitable for being disposed of in normal dumps.;The cast iron bath, kept at high temperature and rapidly circulated by the induced currents which flow through it, constitutes the "reducing section" of the furnace, inside which the reduction takes place of the oxides of metal which constitute the feed: Zn, Pb, Cd, Fe.;The bath covering layer, occupied by the feedstock (pelletized steelworks dusts, granular coal, slagging agents) constitute the oxidizing section of the furnace inside which coal is burnt yielding CO, and and vapours of Zn and other feedstock metals leaving the bath are oxidized again and turn into fumes.;A proper fume collection unit collects the dusts and recovers Zn, Pb, Cd oxides concentrated to more than twice as high levels relatively to their initial concentrations at process beginning.