Iron ore sintering process with reduced emissions of toxic gases by waste gas recirculation

摘要

A method of sintering iron ore in a sinter strand comprises providing a sinter feedstock and depositing said feedstock onto a travelling grate, igniting said feedstock using a sinter strand burner(s), and combusting said feedstock by drawing air through the feedstock with a plurality of wind boxes situated along the length of the strand, to produce sintered products rich in iron and waste gases. Waste gases from only those wind boxes whose temperature exceeds a predetermined level (200-250°C) are recycled to provide combustion feed air for the feedstock or air for the sinter strand ignition burner(s), thereby substantially reducing or eliminating the production and/or emission of dioxins.