Abstract: This method is for producing granular metallic iron in which the relation between the mass ratio (mass %) of the volatile matter content contained in a carbonaceous reducing agent and the average gas flow rate (m/s) of the ambient gas in a heating furnace fulfills expression (1). Mass ratio of volatile matter content??4.62×average gas flow rate+46.7 . . .

Abstract: This method is for producing granular metallic iron in which the relation between the mass ratio (mass %) of the volatile matter content contained in a carbonaceous reducing agent and the average gas flow rate (m/s) of the ambient gas in a heating furnace fulfills expression (1). Mass ratio of volatile matter content??4.62×average gas flow rate+46.7 . . .

Abstract: Provided is a method for manufacturing iron nuggets by which reduced iron obtained by heating and reducing agglomerates, or iron nuggets obtained by melting and aggregating the reduced iron can be prevented from reoxidation inside a movable hearth heating furnace and quality of the reduced iron can be improved. The method involves charging and heating agglomerates including iron oxide and a carbonaceous reducing agent on a hearth of a movable hearth heating furnace, reducing and melting the iron oxide in the agglomerates, and then discharging obtained iron nuggets to the outside of the furnace and recovering the iron nuggets. The agglomerates have a coating layer, including a fluid carbonaceous material, on the surface.

Abstract: 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.

Abstract: A process for producing a molten steel (G) is disclosed in which particulate metallic iron can be more efficiently melted. The process includes the step of melting, in an electric arc furnace (2), all charge for iron which comprises: particulate metallic iron (A) produced by a method including a step in which a feed material comprising a carbonaceous reducing material and an iron oxide-containing substance is heated in a rotary hearth furnace (1) as a reducing/melting furnace and the iron oxide contained in the feed material is thereby reduced in the solid state to yield metallic iron and a step in which the resultant metallic iron is heated to a higher temperature to melt the metallic iron and the molten iron is aggregated while separating the iron from the slag (B); and scraps (D) which are another feed material for iron. The process is characterized in that the content of carbon in the particulate metallic iron (A) is regulated to 1.0-4.

Abstract: A technique that further improves the process for producing granular metal involves heating agglomerates and reducing and melting a metal oxide in the agglomerates. The process includes feeding agglomerates containing a metal oxide and a carbonaceous reducing agent onto a hearth of a moving hearth reduction melting furnace, heating the agglomerates to reduce and to melt the metal oxide, cooling the granular metal obtained by the heating, and discharging the cooled granular metal out of the furnace to recover the same. The agglomerates have an average diameter of not smaller than 17.5 mm are fed onto the hearth when the agglomerates are heated at a spread density of not lower than 0.5 on the hearth.

Abstract: 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.

Abstract: 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.

Abstract: A high purity of molten iron is produced efficiently at a higher productivity, by feeding a raw material mixture containing a carbonaceous reducing agent, an iron oxide-containing material and a CaO-containing material onto a hearth of a moving-hearth reducing furnace, heat-reducing the raw material mixture in the reducing furnace, and melting it in a melting furnace melting, wherein a blending amount of the CaO-containing material in the raw material mixture is adjusted in such a manner that another feeding of the CaO-containing material into the melting furnace makes a basicity of a slag generated in the melting furnace 1.1 or more an feeding amount of the CaO-containing material becomes 40 kg or less per ton of the molten iron obtained in the melting furnace.

Abstract: A method for producing granular iron comprising: charging agglomerates formed from a raw material mixture containing an iron oxide-containing substance and a carbonaceous reducing agent onto a carbonaceous material spread on a hearth of a furnace; and heating the agglomerates to thereby reduce and melt iron oxides in the agglomerates, wherein the temperature of the agglomerates in the furnace is set in a range between 1200° C. and 1500° C.; the oxygen partial pressure in atmospheric gas under which the agglomerates are heated is set to 2.0×10?13 atm or more at standard state; and the linear speed of the atmospheric gas in the furnace is set to 4.5 cm/second or more.

Abstract: A method of making metallic iron in which a compact, containing iron oxide such as iron ore or the like and a carbonaceous reductant such as coal or the like, is used as material, and the iron oxide is reduced through the application of heat, thereby making metallic iron. In the course of this reduction, a shell composed of metallic iron is generated and grown on the surface of the compact, and slag aggregates inside the shell. This reduction continues until substantially no iron oxide is present within the metallic iron shell. Subsequently, heating is further performed to melt the metallic iron and slag. Molten metallic iron and molten slag are separated one from the other, thereby obtaining metallic iron with a relatively high metallization ratio.

Abstract: 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.

Abstract: Metallic iron nuggets made by reducing-melt of a material containing a carbonaceous reductant and a metal-oxide-containing material, the metallic iron nuggets comprising at least 94% by mass, hereinafter denoted as “%”, of Fe and 1.0 to 4.5% of C, and having a diameter of 1 to 30 mm are disclosed.

Abstract: 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.

Abstract: 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.

Abstract: A method of making metallic iron in which a compact, containing iron oxide such as iron ore or the like and a carbonaceous reductant such as coal or the like, is used as material, and the iron oxide is reduced through the application of heat, thereby making metallic iron. In the course of this reduction, a shell composed of metallic iron is generated and grown on the surface of the compact, and slag aggregates inside the shell. This reduction continues until substantially no iron oxide is present within the metallic iron shell. Subsequently, heating is further performed to melt the metallic iron and slag. Molten metallic iron and molten slag are separated one from the other, thereby obtaining metallic iron with a relatively high metallization ratio.

Abstract: A method for producing an iron oxide pellet including the steps of adding water to a raw material mixture comprising iron oxide which serves as a primary component, a carbonaceous material in an amount sufficient for reducing the iron oxide, an organic binder in an amount sufficient for binding the iron oxide and the carbonaceous material, and an inorganic coagulant in an amount of not less than 0.05 mass % and less than 1 mass %; pelletizing the resultant mixture to thereby obtain a green pellet; and drying the green pellet until the moisture content is reduced to equal to or less than 1.0 mass %. The thus-produced iron oxide pellet is charged in a reducing furnace for reduction to thereby obtain a reduced iron pellet.

Abstract: A high purity of molten iron is produced efficiently at a higher productivity, by feeding a raw material mixture containing a carbonaceous reducing agent, an iron oxide-containing material and a CaO-containing material onto a hearth of a moving-hearth reducing furnace, heat-reducing the raw material mixture in the reducing furnace, and melting it in a melting furnace melting, wherein a blending amount of the CaO-containing material in the raw material mixture is adjusted in such a manner that another feeding of the CaO-containing material into the melting furnace makes a basicity of a slag generated in the melting furnace 1.1 or more an feeding amount of the CaO-containing material becomes 40 kg or less per ton of the molten iron obtained in the melting furnace.

Abstract: Metallic iron nuggets made by reducing-melt of a material containing a carbonaceous reductant and a metal-oxide-containing material, the metallic iron nuggets comprising at least 94% by mass, hereinafter denoted as “%”, of Fe and 1.0 to 4.5% of C, and having a diameter of 1 to 30 mm are disclosed.

Abstract: Metallic iron nuggets made by reducing-melt of a material containing a carbonaceous reductant and a metal-oxide-containing material, the metallic iron nuggets comprising at least 94% by mass, hereinafter denoted as “%”, of Fe and 1.0 to 4.5% of C, and having a diameter of 1 to 30 mm are disclosed.