Patent application number | Description | Published |
20090031859 | METHOD FOR PRODUCING METALLIC IRON - A hearth material is laid in the form of a layer on the hearth prior to supply of a mixture containing a carbonaceous reducing agent and iron oxides onto a hearth of a reduction melting furnace, thereby forming a renewable hearth capable of being renewed, and the metallic iron is produced while renewing a part or the whole of the renewable hearth, which has deteriorated during operation, with the hearth material. | 02-05-2009 |
20090183600 | METHOD FOR PRODUCING METALLIC IRON - A method for producing metallic iron in which a mixture including a carbonaceous reducing agent and iron oxide is fed onto a hearth of a moving hearth reducing-melting furnace and is then heated so that the iron oxide is reduced and melted. Metallic iron to be obtained is cooled and is then discharged outside the furnace for recovery. Prior to the feed of raw agglomerates, a granular hearth material is bedded on the moving hearth for forming a layered renewable hearth which can be renewed. Part or the entirety of the renewable hearth which was degraded during operation is renewed, and the hearth material for forming a new renewable hearth is fed. The surface of the newly formed hearth is then leveled and mixture is subsequently fed. | 07-23-2009 |
20120007292 | METHOD AND APPARATUS FOR PRODUCING REDUCED METAL - A feedstock-feeding step of feeding a feedstock containing a carbonaceous reductant and an iron oxide-containing material into a rotary hearth furnace, a heating/reducing step of heating the feedstock to reduce iron oxide contained in the feedstock into reduced iron, a melting step of melting the reduced iron, a cooling step of cooling the molten reduced iron, and a discharging step of discharging the cooled reduced iron are performed in that order in the direction that a hearth is moved. The furnace includes flow rate-controlling partitions, arranged therein, for controlling the flow of furnace gas and the furnace gas in the cooling step is allowed to flow in the direction of the movement of the hearth with the partitions. | 01-12-2012 |
20120205840 | METHOD AND APPARATUS FOR MANUFACTURING GRANULAR METALLIC IRON - A method for manufacturing granular metallic iron by reducing a raw material mixture including an iron oxide-containing material and a carbonaceous reducing agent, comprises: a step of charging the raw material mixture onto a hearth of a moving hearth-type thermal reduction furnace; a step of reducing the iron oxide in the raw material mixture by the carbonaceous reducing agent through the application of heat, thereby forming metallic iron, subsequently melting the metallic iron, and coalescing the molten metallic iron to granular metallic iron while separating the molten metallic iron from subgenerated slag; and a step of cooling the metallic iron to solidify; wherein the heat-reducing step includes a step of controlling the flow velocity of atmospheric gas in a predetermined zone of the furnace within a predetermined range. This method makes it possible to manufacture the granular metallic iron of high quality. | 08-16-2012 |
20130118307 | DEVICE FOR PRODUCING GRANULAR METAL IRON AND PROCESS FOR PRODUCING GRANULAR METAL IRON - A device for producing granular metal iron by placing a mass of a raw material mixture comprising a substance containing iron oxide and a carbonaceous reducing agent onto a heath of a moving heath type heating furnace and heating the mass to reduce iron oxide in the mass, thereby producing the granular metal iron. The device comprises, in addition to the moving heath type heating furnace, a sieving machine, a first magnetic separator and a second magnetic separator, and also comprises a passage through which a discharged substance from the moving heath type heating furnace is supplied to the sieving machine, a passage through which crude granules that have been sieved by the sieving machine are supplied to the first magnetic separator, and a passage through which fine granules that have been sieved by the sieving machine are supplied to the second magnetic separator. | 05-16-2013 |
20150027275 | PROCESS FOR MANUFACTURING REDUCED IRON AGGLOMERATES - A process for manufacturing reduced iron agglomerates which comprises introducing starting agglomerates that comprise both an iron oxide-containing material and a carbonaceous reducing agent onto the hearth of a moving-bed heating furnace, and heating the agglomerates to reduce the iron oxide contained in the agglomerates, wherein the iron oxide-containing material contained in the starting agglomerates has a mean particle diameter of 4 to 23 μm and contains at least 18% of particles having diameters of 10 μm or less. By the use of such starting agglomerates, the process attains: an improvement in the yield of reduced iron agglomerates having large particle diameters; a reduction in the manufacturing time, said reduction leading to an enhancement in the productivity; and a remarkable reduction in the content of impurities such as sulfur in the reduced-iron agglomerates. | 01-29-2015 |
20150322542 | METHOD FOR PRODUCING REDUCED IRON - Provided is a technique for increasing the yield of reduced iron, thereby improving productivity when manufacturing reduced iron by heating an agglomerate. | 11-12-2015 |
20150361515 | METHOD FOR PRODUCING REDUCED IRON AGGLOMERATE - Provided is a method for producing a reduced iron agglomerate, which comprises introducing an agglomerate comprising an iron-oxide-containing substance, a carbonaceous reducing agent, a melting point adjuster and an aid for the melting point adjuster onto a furnace bed of a moving-bed-type heating furnace and then heating the agglomerate on the furnace bed to reduce iron oxide in the agglomerate; and melting the resultant product by additional heating to cause the coalescence of an iron component, thereby producing the reduced iron agglomerate, wherein an agglomerate containing the melting point adjuster that has an average particle diameter of 0.3 mm or less and in which the content of a particle diameter of 0.5 mm or less in an amount of 55 mass % or more is used. Thus, provided is a method which can improve the yield of a reduced iron agglomerate having a large particle diameter and can also reduce the amount of time required for the production of the reduced iron agglomerate to improve the productivity of the reduced iron agglomerate. | 12-17-2015 |