US Patent 8043408 Direct smelting of zinc bearing compounds to produce metallic zinc

A process and apparatus for producing lead and zinc from concentrates of zinc and lead sulfides or oxides includes the steps of:(a) mixing lead ore and/or zinc ore concentrates, iron bearing and carbon containing materials, metallic iron fines and iron oxide fines, carbonaceous reductant, fluxing agent, and a binder to form a mixture;(b) forming agglomerates from the mixture(c) introducing the agglomerates to a melting furnace;(d) maintaining a reducing atmosphere within the melting furnace;(e) vaporizing lead and zinc in the melting furnace at a temperature of 1000 to 1650 C, and removing the lead and zinc from the melting furnace in vaporized form;(f) cooling and condensing the metal vapors to liquid metal; and(g) separating the zinc and lead; and(h) recovering the lead and zinc metal separately.