Recovery of iron, carbon and zinc from steel plant waste oxides using the AISI-DOE postcombustion smelting technology

This report describes a process to recover steel plant waste oxides to be used in the production of hot metal. The process flowsheet used at the pilot plant. Coal/coke breeze and iron ore pellets/waste oxides are charged into the smelting reactor. The waste oxides are either agglomerated into briquettes (1 inch) using a binder or micro-agglomerated into pellets (1/4 inch) without the use of a binder. The iron oxides dissolve in the slag and are reduced by carbon to produce molten iron. The gangue oxides present in the raw materials report to the slag. Coal charged to the smelter is both the fuel as well as the reductant. Carbon present in the waste oxides is also used as the fuel/reductant resulting in a decrease in the coal requirement. Oxygen is top blown through a central, water-cooled, dual circuit lance. Nitrogen is injected through tuyeres at the bottom of the reactor for stirring purposes. The hot metal and slag produced in the smelting reactor are tapped at regular intervals through a single taphole using a mudgun and drill system. The energy requirements of the process are provided by (i) the combustion of carbon to carbon monoxide, referred to as primary combustion and (ii) the combustion of CO and H{sub 2} to CO{sub 2} and H{sub 2}O, known as postcombustion