Method of separating and recovering iron from waste non-ferrous slag discharged from process for smelting of non-ferrous metals, including copper, zinc and lead by physical and chemical separation technique

Abstract

The present invention provides a method of separating and recovering iron from a waste non-ferrous slag, generated in a process for smelting of non-ferrous metals, including copper, zinc and lead, in which a reducing agent and a reaction catalyst are added to the crushed waste non-ferrous slag, and the mixture is subjected to a reduction reaction, thereby converting amorphous iron oxides, bound to alumina, calcium oxide, magnesium oxide, silica, and the like in the waste non-ferrous slag, to crystalline iron (Fe) and iron carbide (FeC); the resulting material is crushed to separate iron and iron carbide obtained by the reduction reaction from components such as alumina, calcium oxide, magnesium oxide, silica, and the like; the crushed material is separated into fractions by particle size; and the fractions are subjected to wet magnetic separation and dry magnetic separation to separate and recover magnetic iron concentrates from the fractions.