Abstract: Recovery of oxide or silicate-bound metals from liquid slag, in metallic or sulphidic form is carried out by reduction with carbonaceous reducing agent, the thermal energy required to maintain the temperature and perform the reduction and sulphidization being provided by blowing gas preheated in a plasma generator below the surface of the slag bath. The vapor of volatile metals is condensed in known manner in a condensor, the non-volatile metals and sulphides formed being collected in the form of molten drops which are allowed to settle out of the slag.

Abstract: A gas mixture obtained from reduction of material containing zinc oxide in a furnace, is cleaned from accompanying vapor of metals or compounds having a boiling point higher than zinc and from accompanying dust particles by cooling the hot gas mixture to almost the saturation temperature of zinc vapor by the introduction therein of solid or liquid metal.

Abstract: Pure ferro-alloy metals are isolated from fine-grained crude oxidic mineral products by reduction melting and subsequent anodic liberation of the iron. The reduction melting is performed in a plasma-heated furnace into which the fine-grained oxide material is blown together with carbon powder and circulating exhaust gas, extremely over-heated in a plasma generator, the quantity of carbon powder being dosed so that most of the alloy metal(s) is converted to carbides during the reduction. After electrolysis, the anode residue will consist primarily of alloy metal carbides from which the metal can be recovered by known methods.