| abstract |
Raw materials for non-ferrous metals, esp. Cu-Zn concentrates, are subjected to complex, continuous processing in two stages: (a) melting in a gas atmos. contg. free O2; and (b) redn. melting using a gas plasma flame at 4000-5000 degrees C while keeping the surface of the melt at 1500-1600 degrees C. In stage (b), the plasma jet pref. enters the melt to stir the oxides, the plasma gas being natural gas or N2, and the melt covered with a layer of coke. the pref. plant consists of a melting chamber (a) which includes a zone (b) contg. a plasma burner, with a gas outlet leading to a chamber (c) for condensn. of metal vapours; more than one plasma burner may be used. Used for the processing of Cu-Zn or Cu-Pb-Zn concentrates, or slags and other residues contg. Zn, Pb, Sb. |