Patent ID: 8961650
Filing Date: 2015-02-24
Classification: C21B,C21C,C22B,F27B,F27D,Y02P

Abstract:
1. A partially-reduced iron producing method comprising the steps of: laying an ignition carbon material to a predetermined height on an endless grate; igniting the ignition carbon material, and then packing raw-material pellets on the ignited ignition carbon material, the raw-material pellets formed by mixing and pelletizing a reduction carbon material and a raw material containing iron oxides; causing a flammable volatile component to be generated from the reduction carbon material in the raw-material pellets and combust, by use of a combustion heat of the ignited ignition carbon material; causing a temperature of the raw-material pellets to further rise by use of a combustion heat of the flammable volatile component, so that a reduction reaction proceeds and a carbon monoxide gas is generated, while causing the raw-material pellets adjacent thereto to be heated by use of the combustion heat, so that a flammable volatile component is generated from the reduction carbon material in the adjacent portions of the raw-material pellets; increasing a concentration of the carbon monoxide gas near the raw-material pellets having the temperature further raised, to a combustion range of the carbon monoxide gas by supplying an oxygen-containing gas to the raw-material pellets having the temperature thereof caused to further rise, so that the carbon monoxide gas combusts and a combustion zone is formed, the oxygen-containing gas made by circulating a remaining portion of the flammable volatile component and the carbon monoxide gas and mixing the remaining portion and the gas with air; and moving the combustion zone sequentially in a bed height direction of a packed bed of the raw-material pellets in a period between supplying of the raw-material pellets onto the ignition carbon material and discharging thereof, so that the packed bed of the raw-material pellet is thermally reduced and a partially-reduced iron is produced.