Abstract: A method of producing reduced iron agglomerates capable of preventing oxidation in the surface layer of the agglomerates and obtaining reduced iron agglomerates having a high degree of metallization, by blowing a methane or methane-containing gas to the reduced iron oxide agglomerates incorporated with carbonaceous material at a surface temperature of 1150° C. or higher during movement in a moving hearth heating type furnace at the end of reduction as the final stage of the stagnation period of the agglomerates in the heating furnace.

Abstract: A moving hearth is formed by providing a layer of hearth material primarily composed of iron oxide on a base refractory in a reducing furnace and then sintering the hearth material so that the sintered moving hearth is not melted at an operational temperature in a reducing step. The moving hearth is more easily constructed compared to providing a shaped or amorphous refractory on the base refractory, has high durability, and can maintain surface flatness during operation.

Abstract: A moving hearth reducing furnace is operated, while a gap is provided between a discharging apparatus for discharging reduced iron agglomerates from the moving hearth reducing furnace and the surface of the moving hearth. The gap prevents squeezing metallic iron powder formed by reduction of powder included in iron oxide agglomerates into the surface of the moving hearth and the formation of an iron sheet. An iron oxide layer formed on the moving hearth during the operation can be periodically scraped off without shutdown of the furnace.

Abstract: In order to be able to process in an economical manner different iron carriers in varying quantitative compositions, a plant for the production of iron melts (4), in particular steel melts, such as crude steel melts, is equipped with an electric are furnace vessel (1), a refining vessel (3) following upon the furnace vessel (1) via a weir (34) and including a bottom departing from the weir (34) in an at least partially downwardly inclined manner and an oxygen supply means (35, 36) as well as an iron melt tap (41) provided in its end region farther remote from the furnace vessel (1), a decanting vessel (2) following upon the furnace vessel (1) and having a common bottom (18) with the furnace vessel (1), said decanting vessel being provided with a slag tap (43) in its end region farther remote from the furnace vessel (1), a supply means (21) supplying liquid pig iron (20) and opening into the furnace vessel (1), a preheating shaft (5) supplying solid iron carries (7), said preheating shaft being arranged a

Abstract: A system for producing direct reduced iron wherein iron oxide material and carbonaceous material is passed successively through an oxidizing zone and a reducing zone of a furnace, each zone fired by oxy-fuel combustion, enabling a reduction in the amount of fuel needed to process the material while generating sufficient carbon monoxide to effect the reduction and ensuring that little or no carbon monoxide is emitted from the furnace.

Abstract: In the method of producing reduced iron according to the invention, fine iron oxides and powdery solid reductants are mixed, compacted into sheet-like compacts, and charged onto the hearth of a reduction furnace for reduction while maintaining the temperature inside the furnace at not less than 1100.degree. C. As the sheet-like compacts can be obtained by compacting mixture of raw material by use of rollers or the like, processing time is much shorter than the case of pelletization or agglomeration. A drying step is unnecessary since feeds are placed no the hearth via a feeder chute or the like. The method is carried out with ease by use of the facility according to the invention. High quality hot metal can be produced by charging reduced iron in hot condition obtained by the method described as above into a shaft furnace or a in-bath smelting furnace for melting at high thermal efficiency.

Abstract: A system for producing direct reduced iron wherein iron oxide material and carbonaceous material is passed successively through an oxidizing zone and a reducing zone of a furnace, each zone fired by oxy-fuel combustion, enabling a reduction in the amount of fuel needed to process the material while generating sufficient carbon monoxide to effect the reduction and ensuring that little or no carbon monoxide is emitted from the furnace.

Abstract: A method and apparatus for continuously producing metals such as zirconium, hafnium, titanium, niobium, vanadium, silicon and tantalum. The corresponding metal halide is reacted with a metallic reducing agent such as aluminum, calcium, magnesium and sodium in a reactor where the reaction takes place at a temperature where the metal reducing agent is below its vaporization temperature and where the metal halide is above its vaporization temperature. The metal formed by the reaction is recovered from the reactor by collecting it in a pool of molten product metal contained in a cold wall induction heated receptacle in the reactor from which the metal product is removed.

Abstract: A process for continuously smelting iron ore by use of coal to yield molten iron or semi-steel is disclosed. The process comprises the steps of establishing a melt covered by slag; inducing the slag and the molten iron to flow countercurrently to one another, toward opposite ends of the smelter; maintaining iron oxide-reducing conditions in that zone of the smelter towards which the slag flows; maintaining carbon-oxidizing conditions in that zone of the smelter towards which the molten iron flows; continuously or semicontinuously tapping the slag from the reducing zone end of the smelter; continuously or semicontinuously tapping the molten iron from the oxidizing zone end of the smelter; and adding to both zones iron ore, coal, oxygen, and flux at addition rates sufficient to keep the molten iron in the reducing zone substantially saturated with carbon, maintain in the slag being tapped an FeO content of about 5 weight percent or less, and maintain in the molten iron being tapped a carbon content of about 0.

Abstract: An apparatus for improving mass transfer in a multiple hearth furnace has a plurality of risers adjacent the furnace center shaft which are in fluid communication with a source of treatment fluid. The risers have radially extending branch pipes, each pipe having a plurality of downcomers corresponding to the rabbles on an adjacent rabble arm. The downcomers have outlets or nozzles at their distal ends and they are preferably located adjacent a rear face of the rabble, near a trailing edge. In operation, as the rabbles plough over the material on the furnace hearth, the downcomers inject a treatment fluid, such as steam or reducing gas, into the material at the point of stirring. This ensures full exposure of the material to the treatment fluid. A second embodiment places the outlets beneath the top surface of the material to be treated. A method for mass transfer on a rotary hearth furnace is also disclosed.

Abstract: Device (10) for igniting a moving bed of a mixture (12), in particular a mixture comprising iron ore and coke the combustion of which produces the agglomeration of the ore. The device comprises a hood (14) under which burners (16) are arranged and through which the mixture bed (12) travels. The burners (16) have axes oriented in directions substantially perpendicular to the surface of the mixture bed (12) and each burner (16) has a gas flow and an air flow which are individually adjustable, the burners being of the high-speed gas ejection type.

Abstract: A sintering method, which includes igniting a layer of raw materials and providing a downwardly directed air suction is improved by applying a magnetic field to the materials for which a predetermined amount of sintering has been completed in the upper region of the layer of raw materials. The sintering is continued while a magnetic floating force is applied to such sintered cakes. An apparatus for carrying out the method is provided.

Abstract: A method and apparatus for reducing iron in a steelmaking process including a closed thermal transfer system in which a flow of process ingredients including iron ore is directed in a descending, preferably spiral path defined by a downwardly spiraling pipe with the process ingredients moving in countercurrent flow relation to a continuous flow of reducing gases ascending within the pipe to reduce the process ingredients to a continuously flowing stream of molten iron and slag which moves downwardly in the spiral pipe and into a hearth furnace.

Abstract: A method of producing iron from finely divided iron oxide comprising the steps of: mixing iron oxide or iron ore fines with finely divided coal and a binder to form a mixture, agglomerating the mixture by compacting, pelletizing, or briquetting the mixture to form agglomerates or pellets, introducing the pellets to a rotary hearth furnace to prereduce the iron in the pellets, introducing the prereduced pellets into a smelting reduction vessel as the metallic charge constituent, introducing particulate carbonaceous fuel and oxygen to the smelting reduction vessel through the bottom of the vessel to react with the melt or bath within the vessel, reduce the iron to elemental iron and form an off gas containing CO and H.sub.2 introducing the off-gas into the rotary hearth furnace as process gas to prereduce the pellets therein, and drawing off the hot metal from the smelting reduction vessel.The prereduced compacts are preferably discharged from the rotary hearth furnace at a temperature of at least 1000.degree.

Abstract: A rotary hearth adapted to rotate in horizontal plane having a top surface made of a loose granular refractory material, advantageously dead burned dolomite grain.

Abstract: A treating furnace for manufacturing non-fired iron-bearing pellets comprising a green iron-bearing pellet inlet at one end thereof and a non-fired iron-bearing pellet outlet at the other end. Green iron-bearing pellets are continuously fed into the treating furnace through said inlet and after being heated are discharged through said outlet. The treating furnace contains at least one heating gas blowing port for blowing heating gas into the furnace and at least one heating gas discharge port for discharging said gas after it has heated the pellets. The furnace also contains a preheating zone and at least one preheating gas blowing port and at least one preheating gas discharge port to pass preheating gas through said preheating zone. The heating gas discharged from the heating gas discharge port is used as the preheating gas.

Abstract: A shaft furnace for reducing ores with a gas, wherein the furnace is constructed to destroy the plug-flow state of ores in or above a plug-flow zone where a reduction ratio of the ores is 50 to 70%, in order to prevent the clustering by changing the plug-flow zone into a shear-flow zone. Further, the shaft furnace for reducing ores with a gas is so constructed that a hydraulic radius R (cm) of the furnace in the reduction zone in which the reduction ratio is greater than 50% is selected to be,R.ltoreq.120 exp(8.6-0.009T)wherein T denotes the temperature (.degree.C.) of the reducing gas, in order to prevent the clustering.

Abstract: A method and apparatus for producing molten iron in which pulverized coal is gasified with oxygen in an iron melting chamber, iron pellets on an upstanding hearth in the melting chamber are exposed to the gasification heat and melted. Molten iron trickles down from the hearth to a surrounding liquid bath. Off-gases from the chamber are utilized for direct reduction of iron oxide pellets to produce hot reduced iron pellets which are melted in the chamber.

Abstract: A method and apparatus for the direct reduction of iron ore are disclosed. A mixture of iron ore, solid carbonaceous fuel and, if sulfur is present, calcined limestone or dolomite, are used. The carbonaceous material can be cellulosic material (wood waste, paper, particularly municipal trash, garbage, etc.), charcoal, or coal (preferably sub-bituminous coal or lignite). The above feed is continuously charged into a gasification and initial reduction zone of a shaft furnace which is partitioned partially from the remainder of the furnace. Oxygen and hot steam are introduced into the upper portion of the said zone. Partial combustion or pyrolysis of the fuel and reaction with steam take place, producing reducing gas which initiates reduction of the iron ore. Ore and gas flow downwardly through conduits into the final reduction zone. Meanwhile, hydrogen-enriched reducing gas is introduced in the middle of the final reduction zone.

Abstract: The invention concerns an apparatus for heat exchange between a hot and a cold body in particular in form of fluids, divided by a partition wall, in which apparatus a portion of the wall, contacting the hot fluid, is moved and is brought in place of a corresponding wall portion contacting the cold fluid. The invention concerns also the application of the apparatus in a chamber for ore reduction.