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: The amounts of a CaO-containing substance, an MgO-containing substance, and a SiO2-containing substance, contained in a raw material mixture, are adjusted such that manufacturing operation is performed with the slag basicity (CaO+MgO)/SiO2 of 1.3 to 2.3, and with MgO-concentration of 5 to 13% by mass as to the slag composition, which are dependent upon the concentration of each of CaO, MgO, and SiO2, contained in the raw material mixture. This provides a manufacturing method for high-quality granulated metallic iron with low sulfur concentration, wherein a raw material mixture containing an iron-oxide-containing substance such as iron ore and a carbonaceous reducing agent such as a carbon material are subjected to reducing and melting with a moving hearth-type reducing furnace while suppressing sulfur concentration as much as possible, generated in the granulated metallic iron, particularly due to the carbon material such as coal.

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 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 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: 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: A method for making metal nuggets comprises heating a material containing a metal-oxide-containing substance and a carbonaceous reductant to reduce metal oxide in the material and then further heating the produced metal so as to melt the metal while allowing the metal to separate from a by-product slag component and to form granular iron. A cohesion accelerator for the by-product slag is mixed into the material to produce metal nuggets having a high metal purity, a large diameter, and superior transportation and handling qualities at a high yield and high productivity.

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 capable of suppressing damages to furnace wall refractories in a melting furnace and making the working life of them longer and a technique capable of obtaining a molten iron with homogenized composition while keeping a high productivity upon arc heating a pre-reducing iron in a melting furnace to obtain a molten iron, the method comprising supplying a pre-reducing iron to a stationary non-tilting type melting furnace and melting the iron by an arc heating mainly composed of radiation heating, the melting being performed while keeping a refractory wearing index RF represented by the following equation at 400 MWV/m2 or less. RF=P×E/L2 (wherein RF represents the refractory wearing index (MWV/m2); P represents an arc power for one phase (MW); E represents an arc voltage (V); and L represents the shortest distance between the electrode side surface of a tip within an arc heating furnace and a furnace wall inner surface (m).

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.

Abstract: The present invention provides a method of producing metallic iron nuggets with a high yield and good productivity, and more particularly a method which can produce metallic iron nuggets which have a high Fe purity and are excellent in transporting and handling due to a large grain diameter with a high yield and good productivity, when they are produced by reducing and melting raw material containing iron oxide such as iron ore and carbonaceous reducing agent such as coke.

Abstract: A method of manufacturing a molten metal iron by charging a starting material at least comprising a carbonaceous reducing material and an iron oxide-containing material into a rotary hearth furnace, reducing under heating the charged starting material into a solid reducing iron, carburizing the metal iron in the solid reduced iron with the carbon ingredient in the carbonaceous reducing material, thereby melting the metal iron, separating the slag ingredient contained in the starting material by the melting, and discharging the molten metal alloy in the molten state as it is to the outside of the rotary hearth furnace for recovery, wherein a downward inclined surface is disposed at an angle 3 to 30° relative to the horizontal plane on the upper surface of a hearth of the rotary hearth furnace on which the starting material is placed, and the molten metal iron is discharged at the discharging position for the molten metal iron from the lowest portion of the inclined surface.

Abstract: A method capable of suppressing damages to furnace wall refractories in a melting furnace and making the working life of them longer and a technique capable of obtaining a molten iron with homogenized composition while keeping a high productivity upon arc heating a pre-reducing iron in a melting furnace to obtain a molten iron, the method comprising supplying a pre-reducing iron to a stationary non-tilting type melting furnace and melting the iron by an arc heating mainly composed of radiation heating, the melting being performed while keeping a refractory wearing index RF represented by the following equation at 400 MWV/m2 or less.

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 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 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: The present invention is an apparatus and method for the direct reduction of iron oxide utilizing a rotary hearth furnace to form a high purity carbon-containing iron metal button. The hearth layer may be a refractory or a vitreous hearth layer of iron oxide, carbon, and silica compounds. Additionally, coating materials may be introduced onto the refractory or vitreous hearth layer before iron oxide ore and carbon materials are added, with the coating materials preventing attack of the molten iron on the hearth layer. The coating materials may include compounds of carbon, iron oxide, silicon oxide, magnesium oxide, and/or aluminum oxide. The coating materials may be placed as a solid or a slurry on the hearth layer and heated, which provides a protective layer onto which the iron oxide ores and carbon materials are placed. The iron oxide is reduced and forms molten globules of high purity iron and residual carbon, which remain separate from the hearth layer.

Abstract: The present invention provides a method of producing metallic iron nuggets with a high yield and good productivity, and more particularly a method which can produce metallic iron nuggets which have a high Fe purity and are excellent in transporting and handling due to a large grain diameter with a high yield and good productivity, when they are produced by reducing and melting raw material containing iron oxide such as iron ore and carbonaceous reducing agent such as coke.

Abstract: The present invention is an apparatus and method for the direct reduction of iron oxide utilizing a rotary hearth furnace to form a high purity carbon-containing iron metal button. The hearth layer may be a refractory or a vitreous hearth layer of iron oxide, carbon, and silica compounds. Additionally, coating materials may be introduced onto the refractory or vitreous hearth layer before iron oxide ore and carbon materials are added, with the coating materials preventing attack of the molten iron on the hearth layer. The coating materials may include compounds of carbon, iron oxide, silicon oxide, magnesium oxide, and/or aluminum oxide. The coating materials may be placed as a solid or a slurry on the hearth layer and heated, which provides a protective layer onto which the iron oxide ores and carbon materials are placed. The iron oxide is reduced and forms molten globules of high purity iron and residual carbon, which remain separate from the hearth layer.