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 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 reductant to cause the reduced iron to melt, while separating off gangue components contained 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.

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: Molten iron is prepared by (1) providing iron oxide and a carbonaceous reducing agent, (2) preparing a shaped product from the carbonaceous reducing agent and the iron oxide, (3) preparing solid reduced iron from the shaped product, wherein the solid reduced iron has a metallization of at least 60%, a specific gravity of at least 1.7, and a carbon content of at least 50% of the theoretical amount required for reducing the iron oxide remaining in the solid reduced iron, and, (4) before substantial cooling occurs, heating the solid reduced iron in an arc heating-type melting furnace at a high temperature. The molten iron can be prepared efficiently from iron ores of relatively low iron content without causing erosion of refractories, at high energy and high reduction efficiencies, and by a simple operation in a simple facility.

Abstract: A method of making metallic iron includes heating a mixed powder containing iron oxide and a carbonaceous reducing agent on a hearth to reduce the iron oxide and melt the reduced iron. Preliminary molding of the mixed powder starting material into pellets is not required. The resulting metallic iron contains extremely low concentrations of slag ingredients, even when the mixed powder starting material contains only low concentrations of iron oxide.

Abstract: Molten iron is prepared by (1) providing iron oxide and a carbonaceous reducing agent, (2) preparing a shaped product from the carbonaceous reducing agent and the iron oxide, (3) preparing solid reduced iron from the shaped product, wherein the solid reduced iron has a metallization of at least 60%, a specific gravity of at least 1.7, and a carbon content of at least 50% of the theoretical amount required for reducing the iron oxide remaining in the solid reduced iron, and, (4) before substantial cooling occurs, heating the solid reduced iron in an arc heating-type melting furnace at a high temperature. The molten iron can be prepared efficiently from iron ores of relatively low iron content without causing erosion of refractories, at high energy and high reduction efficiencies, and by a simple operation in a simple facility.

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: Described herein is a process for melting iron material in the production of molten iron, in which cold iron material such as scraps, cold pig iron or reduced iron is charged into a melting furnace, the process comprising: feeding a carbon-containing solid material into a precombustion vessel for primary combustion therein with supply of an oxygen-containing gas with an oxygen content corresponding to 0.4 to 0.9 of theoretical air ratio; separating combustion residues of the carbon-containing solid material from the resulting hot reducing gas; and introducing the reducing gas into the melting furnace for secondary combustion therein with supply of an oxygen-containing gas holding an oxygen concentration corresponding to 0.7 to 1.3 of theoretical air ratio in total with the oxygen-containing gas supplied to the precombustion furnace.

Abstract: A probe for detecting wear of a refractory wall, including plural sheathed probe elements of different lengths each consisting of a pair of high melting point wires disposed in parallel and insulated from each other except at least the fore end portions of the wires which form a normally closed or normally open sensing point, a sheath enclosure accommodating the probe elements such that the sensing points of the respective probe elements are located at different positions along the length of the sheath enclosure and holding the probe elements in parallel relation and out of contact with each other, and a number of dummy elements formed of a material similar to the probe elements and connected to the fore ends thereof in a manner to complement the lengths of the shorter of the probe elements. There is also disclosed a detection circuit for monitoring wear of a refractory wall in a molten metal processing apparatus in a simple and accurate manner by the use of the probe.

Abstract: A blowing tuyere to be embedded in a bottom of side wall of a molten metal bath container for blowing a gas thereinto, the tuyere including a cylindrical core body fixedly located at the center of the tuyere and an outer tube fixed concentrically around the core body with a gap of a predetermined width to form an annular blowing passage therebetween.

Abstract: A method for stably refining high carbon steel by top and bottom blown converter refining in which the entire quantity or part of refining pure oxygen is blown onto molten iron through a top blowing lance nozzle while blowing an inert gas into the converter through a nozzle at the bottom thereof, and wherein the bottom blown inert gas is fed at a rate less than 0.09 Nm.sup.3 /min.multidot.ton during the blowing and/or at a rate less than 0.03 Nm.sup.3 /min.multidot.ton in a controlling stage immediately after turndown.