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 producing metallic iron by reducing raw materials including an iron-oxide containing material and a carbonaceous reducing agent under heating, which can minimize re-oxidization of the metallic iron and can efficiently produce metallic iron having a high metallization ratio and high iron purity at high yield. The method produces metallic iron, by heating raw materials including a carbonaceous reducing agent and an iron-oxide containing material in a reduction melting furnace of the moving hearth type, and reducing and melting iron oxides in the raw materials. The reduction melting furnace is partitioned into at least three zones in a hearth moving direction, at least one partitioned zone upstream in the hearth moving direction is a solid-state reducing zone, at least one downstream partitioned zone is a carburization melting zone, and a reduction aging zone is between the solid-state reducing zone and the carburization melting zone.

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: In a method of producing metallic iron by reducing and melting a raw material, which contains an iron oxide-containing material and a carbonaceous reducing agent, by heating, the raw material for producing metallic iron is supplied after a powder and granular atmosphere control carbonaceous material is spread on a hearth of a heat-reducing furnace. In this case, a non-resolidificable carbonaceous material is used as the atmosphere control carbonaceous material, and thus a phenomenon that the powder and granular carbonaceous material is resolidified into a rice-cracker-like shape can be suppressed, thereby permitting solid-phase reduction with high efficiency and stable operationality.

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.

Abstract: It is an object of the present invention to provide a technique for solving the following problem by properly controlling the flow of gas such as air (oxidizing gas): a problem that the degree of reduction cannot be increased due to the air entering a feedstock-feeding zone or a discharging zone. The technique is a method for producing reduced iron. The method includes 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, these steps being performed in that order in the direction that a hearth is moved.

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 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: An object of the present invention is to provide a method for producing metallic iron, in which after 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. In the method described above, even when powdered metallic iron is squeezed into the surface of the hearth, or the hearth is damaged by slag infiltration and corrosion, the removal and repair can be easily performed, the operation rate and maintenability of the hearth can be improved, and hence a long continuous operation can be suitably performed.

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: In a method of producing metallic iron by reducing and melting a raw material, which contains an iron oxide-containing material and a carbonaceous reducing agent, by heating, the raw material for producing metallic iron is supplied after a powder and granular atmosphere control carbonaceous material is spread on a hearth of a heat-reducing furnace. In this case, a non-resolidificable carbonaceous material is used as the atmosphere control carbonaceous material, and thus a phenomenon that the powder and granular carbonaceous material is resolidified into a rice-cracker-like shape can be suppressed, thereby permitting solid-phase reduction with high efficiency and stable operationality.

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 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 method producing metallic iron by reducing raw materials including an iron-oxide containing material and a carbonaceous reducing agent under heating, which can minimize re-oxidization of the metallic iron and can efficiently produce metallic iron having a high metallization ratio and high iron purity at high yield. The method produces metallic iron, by heating raw materials including a carbonaceous reducing agent and an iron-oxide containing material in a reduction melting furnace of the moving hearth type, and reducing and melting iron oxides in the raw materials. The reduction melting furnace is partitioned into at least three zones in a hearth moving direction, at least one partitioned zone upstream in the hearth moving direction is a solid-state reducing zone, at least one downstream partitioned zone is a carburization melting zone, and a reduction aging zone is between the solid-state reducing zone and the carburization melting zone.

Abstract: The present invention is intended to provide a method for producing metallic iron, which comprises the steps of supplying a mixture containing a carbonous reducing agent and iron oxides onto a hearth of a reduction melting furnace of the moving hearth type, heating the mixture for reduction melting of the iron oxides, cooling thus-obtained metallic iron, and discharging the metallic iron to the outside of the furnace for recovery. The method can easily remove or repair the surface of a hearth even when metallic iron powder is buried in the hearth surface or even when the hearth surface suffers from slag infiltration and erosion, can increase an availability factor and maintainability of the hearth, and is suitably practiced for long-term continuous operation.

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 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 %; pellelizing 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: The present invention is directed to a method of producing granular metallic iron, including: heating a formed raw material comprising a carbonaceous reductant and a substance containing iron oxide in a reduction melting furnace to subject the iron oxide contained in the formed raw material to solid-state reduction; and carburizing reduced iron resulting from the solid-state reduction with carbon contained in the carbonaceous in the formed raw material and causing resulting molten metallic iron to coalesce into the granular metallic iron, wherein an atmospheric gas present in proximity to the formed raw material in the carburizing and melting step has a reduction degree of not less than 0.5. The present invention is also directed to a method of producing metallic iron, including forming a deposit layer containing slag produced in the reduction melting process on hearth refractories, thereby protecting the hearth refractories while producing the metallic iron.