Abstract: In a process for the direct reduction of iron-oxide containing material, synthesis gas is mixed with top gas formed in the direct reduction of the iron-oxide containing material and is used as a reducing gas for direct reduction. In order to avoid metal dusting despite an elevated CO-content of the reducing gas, or to reduce metal dusting, in a procedurally simple and cost-saving manner while minimizing the energy demand, an H.sub.2 O content of between 1 and 2%, preferably amounting to about 1.5%, is achieved in the reducing gas by subjecting a partial volume of the top gas to CO.sub.2 scrubbing prior to being used as a reducing gas, wherein the top gas subjected to CO.sub.2 scrubbing is mixed with the synthesis gas, is brought to a predetermined temperature by direct water irrigation while being saturated with H.sub.2 O, after direct water irrigation is heated to a temperature above the saturation temperature by admixing CO.sub.2 -unscrubbed top gas, and subsequently is used as a reducing gas.

Abstract: A method for direct reduction of oxides includes the steps of: providing a reduction zone for direct reduction of oxides and a gas reforming zone communicating with the reduction zone; feeding metal oxides to the reduction zone; feeding a gas mixture comprising methane and an oxygen source to the gas performing zone to provide a reformed gas comprising hydrogen and carbon monoxide; contacting the oxides and the reformed gas in the reduction zone to provide a reduced metal and a top gas; and treating the top gas so as to provide the gas mixture.

Abstract: With a process for the direct reduction of particulate iron-containing material by fluidization, reformed gas, at least partially freed from CO.sub.2, is supplied to a fluidized-bed reduction zone as a reducing gas and is carried off from the same as a top gas and at least a portion of the top gas together with reformed gas is utilized for direction reduction. To economize on parts of the plant that are impinged on by reducing gas and in order to achieve savings in terms of heating costs, CH.sub.4 and N.sub.2 are, in addition to CO.sub.2, at least partially removed by adsorption, from 50 to 100% of the reformed as and 0 to 100% of the top gas, and the tail gas removed from the reformed gas and/or the top gas by adsorption is utilized as a heating gas.

Abstract: A plant for a smelting reduction process for pig iron production using coal and oxygen-containing gas is obtained by converting an existing blast furnace plant by replacing the blast furnace by apparatus including at least one metallurgical vessel for carrying out the smelting reduction process, while retaining at least partly at least one of the following components of the existing blast furnace plant:i) storage bins for iron oreii) storage bins for coke, as storage bins for coaliii) a casting house, for tapping of the metallurgical vesseliv) a gas discharge system for hot gas including dedusting means,v) a cooling water supply system.

Abstract: A reduction apparatus and a method for efficient reduction of fine iron ores of wide grain range comprising serially arranged a drying/preheating furnace, a first reducing furnace for prereduction and a second reduction furnace for final reduction, each working with bubbling fluidized bed and being connected each to a cyclone for capturing iron ore dust contained in the exhaust gases, having each a tapered shape smoothly expanded outwards and thus considerably decreasing elutriation of fine particles, increasing the reduction efficiency and enhancing the utilization of the reducing gas.

Abstract: Annealing is performed in the annealing chamber (2) of the annealing furnace (1) under a protective gas atmosphere. A partial-stream cleaning device (3) for the protective gas is connected to the annealing chamber. The protective gas can be cooled, the condensate forming from water vapour and rolling oil residues is then separated and/or undesirable gas components are removed by adsorption. Once the cleaning process has been running for so long that the protective gas essentially no longer contains any rolling oil residues, the protective gas may be passed through a hot reaction chamber (4) in which oxygen is removed from it so that the dew point drops and easily oxidised alloying components of the annealing charge are protected against oxidation.

Abstract: A coke-fired cupola, including: a furnace shaft having a well at one end, a charging device connected to the shaft, a lower-mouth exhaust connected to the shaft below the charging device, and a furnace gas exhaust ring arranged at the shaft below the charging device and the lower-mouth exhaust. Additionally, at least one nozzle is connected to the shaft above the well. The at least one nozzle has a centrally run oxygen lance. A gas recirculating circuit is provided for connecting the furnace gas exhaust ring to the at least one nozzle. The gas recirculating circuit includes an exhaust device connected to the furnace gas exhaust ring, a recirculating gas ring connected to the at least one nozzle and a recirculating gas duct connected between the exhaust device and the recirculating gas ring.

Abstract: The surfaces of a metal or alloy component are scrubbed by a high-velocity stream of inert gas at temperatures which facilitate removal of contaminants. Simultaneous with scrubbing, the impurities are captured in a separated loop of one or more "getter" filters operating at optimized temperatures. The scrubbing and "getting" functions are followed by a rapid elevation of the temperature of the component by heating the inert gas, now essentially free of contaminants which would otherwise react with the component surface at the elevated temperatures. Thereafter, a specific protective layer-forming agent is introduced into the inert gas stream at an ideal temperature, which agent will react predictably with the component being treated to form a predetermined protective coating on its surface.

Abstract: The combined installation comprises at least one metal production unit (II), including at least one, and typically a series of metal production or treatment units (1-6), and at least one air gas separation unit (III) including at least one outlet for at least one air gas (14-18), the units being supplied with compressed air with a low water vapor content by a common compressed air production unit (I), and with at least one of the gas outlets (14-18) from the separation unit (III) connected to at least one of the devices (1-6) of the production unit, to supply the latter with gas.

Abstract: A direct reduction plant for reducing raw iron ore fines in fluidized beds in a virtually closed gas system comprises an ore feed assembly, a preheat assembly, a multi-stage reactor assembly, a compacting/inerting assembly, and a reducing gas assembly, Reducing gases utilized in the plant are produced from externally provided natural gas and recycled reducing gases from said reactor assembly.

Abstract: A method and apparatus for producing direct reduced iron from iron oxide fines. The iron oxide raw material is conducted through a series of circulating fluidizable beds in which the fluidizing gas is a strong reducing gas mixture, which allows intimate contact between the fines and the reducing gas to facilitate the direct reduction of the iron oxide fines to metallized iron.

Abstract: A process and installation for preheating scrap containing organic matter, in which flue gas is afterburned in an afterburner combustion chamber at a temperature at more than 1200.degree. C. The after-burned hot flue gases are guided, without being cleaned, via a heat exchanger. Fresh intake air is heated in the heat exchanger by sensible heat of the after-burned hot flue gases. A first portion of the heated intake air at a temperature above an ignition temperature of organic matter is guided in adjustable amounts through at least one basket filled with scrap. Another portion of the heated air exiting the heat exchanger is made available in adjustable quantities to the afterburner as hot blast and/or mixed in the another portion of heated intake air with the after-burned hot flue gases.

Abstract: The invention is directed to a process and apparatus for preheating and transferring scrap into smelting furnaces for steelmaking or the like. The scrap is preheated by energy contained in the waste gases from the smelting furnace, which energy comprises sensible heat and chemically bonded heat in the combustible portions of the waste gases. The furnace-waste gases are guided to a waste-gas combustion chamber incorporated in a waste-gas outlet line and are burned therein with air to generate hot combustion gases which are fed to the scrap in the receptacles at a preheating station and then sucked out via an exhaust fan. After the scrap reaches the desired temperature, the receptacle containing the preheated scrap is removed from the preheating station so that the preheated scrap may be transferred to the smelting furnace. During this receptacle changeover process, the hot combustion gases are rerouted to another scrap-filled receptacle at the preheating station using a pipeline arrangement.

Abstract: A steelworks apparatus includes a closed tiltable arc furnace for melting scrap and having a lower vessel part for containing the melt and an upper vessel part connected to an exhaust gas assembly and closed by a furnace roof. A sealable charging assembly is formed of at least two stack-like storage containers which are connected at their top ends to the exhaust assembly and which include gas-permeable, scrap-retaining flaps that are movable between open and closed positions at the bottom end of each respective storage container. A compensation component is located connectingly between the storage containers and the lower furnace vessel part for accommodating relative movements of and between the furnace and storage containers while gas-tightly preventing leakage or escape of gases from between the relatively moved or shifted structures during or as a result of operative tilting of the furnace.

Abstract: In a filter dust melting furnace, the waste gases occurring in the interior (9) of the furnace are conducted outward through a waste-gas line (5) in the furnace top. Provided in the course of the waste-gas line is a quench (20) for the abrupt cooling of the waste gas by cold quenching air acting on it. To prevent deposits in the waste-gas line, the quench (6) is arranged in the section of the waste-gas line (5) which directly adjoins the furnace vessel (1) and extends essentially vertically, and means are provided for cooling the quench and the section of the waste-gas line (5) located downstream after the quench.

Abstract: A sinterable mixture comprising iron-containing materials and solid fuel is sintered on a sintering machine; to decrease the rate at which exhaust gas is to be removed and to produce a desirable sinter, a part of the exhaust gas is enriched to an oxygen content of up to 24% by the addition of higher-oxygen gases and is then recirculated as a recycle gas, and exhaust gas is removed as a tail gas from the process only at a rate which corresponds to the rate of the gas which is formed during the sintering process plus the rate of the gas added for enriching plus the rate of inleaked air which has infiltrated from the outside minus the rate of oxygen consumption.

Abstract: An object of the present invention is to provide method and apparatus for manufacturing medium or low carbon ferromanganese at reduced running costs.In order to achieve the above object, the present invention resides in charging molten high carbon ferromanganese into a refining vessel of a top blowing type, and blowing oxygen gas on the surface of the molten high carbon ferromanganese from above and injecting a mixed gas having the following composition into the molten high carbon ferromanganese from bottom. The mixed gas composition comprises 65-100% of CO, 0-25% of CO.sub.2 and 0-10% of N.sub.2. In a case, argon gas is used as the bottom-blown gas.

Abstract: An improved method and apparatus for forming metallized iron by direct reduction of particulate iron oxide is disclosed. Spent reducing gas is recycled from the reduction furnace through a cooler-scrubber and a catalyst-containing stoichiometric gas reformer. Upon removing the process gas from the cooler-scrubber, it is contacted with a chlorine dioxide spray, then compressed and cooled, the sulfur compound removed, and the process gas recycled either into the furnace cooling zone, or directly into the reformer, or divided and directed into both uses. Thus, most of the sulfur containing components of the spent reducing gas are removed, thereby reducing the sulfur contamination of the gas reformer catalyst. Reducing sulfur contamination of the gas reformer catalyst improves the overall efficiency of the direct reduction process. Either high sulfur ores, or high sulfur process gas, or both can be utilized in the invented process.

Abstract: Continuous melting of lightweight shredded metal, e.g., in the recycling of aluminum can scrap is achieved by feeding lightweight scrap portions into a melting chamber through which a heated gas stream flows upwardly at a temperature in excess of the metal melting point and at such velocity that the scrap portions are borne in the flow within the chamber until they melt into denser droplets or globules which drop from the chamber and are collected in a holding furnace.

Abstract: In a process for the direct reduction of particulate iron-oxide-containing material by the fluidized bed method, reformed gas is mixed with top gas forming in the direct reduction of the iron-oxide-containing material and is fed to a fluidized-bed reduction zone as a reducing gas. To lower the energy demand and utilizing the potential of the reducing gas, both the top gas and the reformed gas are subjected to CO.sub.2 scrubbing and the reducing gas formed by mixing top gas with reformed gas is adjusted to an H.sub.2 content ranging between 45 and 75%, preferably between 50 and 65%, and to a CO content ranging between 10 and 20%.

Abstract: An improved method and apparatus for forming metallized iron by direct reduction of particulate iron oxide is disclosed. Spent reducing gas is recycled from the reduction furnace through a cooler-scrubber and a catalyst-containing stoichiometric gas reformer. Upon removing the process gas from the cooler-scrubber, it is contacted with a chlorine dioxide spray, then compressed and cooled, the sulfur compound removed, and the process gas recycled either into the furnace cooling zone, or directly into the reformer, or divided and directed into both uses. Thus, most of the sulfur containing components of the spent reducing gas are removed, thereby reducing the sulfur contamination of the gas reformer catalyst. Reducing sulfur contamination of the gas reformer catalyst improves the overall efficiency of the direct reduction process.

Abstract: An improved batch coil furnace is disclosed in that the annealing stand or base of the furnace is provided with a source for auxiliary heating or cooling of the work. A cylindrical containment wall is heated by hot burner products of combustion convectively impinging the outside surface of the containment wall. A unique jet tube impingement bundle is positioned within the base to form the recirculating cover atmosphere into jet streams which convectively impinge the inside surface of the containment wall. The furnace atmosphere is thus heated prior to being recirculated into the inner cover with the result that the temperatures of all the coils within the inner cover are more uniform. Provisions are made for cooling the outside surface of the containment wall after the coils have been heated to their transformation temperature.

Abstract: The present invention relates to a steel heating furnace which permits free setting of an in-furnace temperature pattern or gradient as desired. A steel heating furnace 1 includes at least one or more burner systems of regenerative heating, each being arranged to supply a combustion air and exhaust a combustion gas through a regenerative bed. Those burner systems are disposed in each of plural zones which are defined within a single furnace body, or in each of unit furnaces 2. The unit furnaces 2 are interconnected to form a single furnace body. The amount of combustion may be controlled for each zones or each unit furnaces 2 to enable free variation of in-furnace temperature per zone or per unit furnace 2 so that a desired in-furnace temperature pattern gradient in the entire furnace 1 may be set easily. The steel heating furnace 1 may be constructed with a required length and in-furnace temperature pattern, by interconnecting the unit furnaces.

Abstract: A process for recycling hot dust from a gasifier or melt-down gasifier by means of a hot gas cyclone separator integrated into a pipe system is described, together with the associated apparatus. The hot dust from the hot gas cyclone separator is supplied by means of a lock system to a burner in order to overcome the pressure difference between the hot gas cyclone separator and the melt-down gasifier. By means of the lock system the dust is supplied from a lower pressure zone to a higher pressure zone. The dust to be recycled comprises coke or a mixture of coke and iron particles.

Abstract: Method of producing pig iron in a blast furnace. At least a portion of a top gas from a blast furnace is collected, dried and then heated to an elevated temperature preferably in the range of 900.degree.-1000.degree. C. An oxygen-enriched hydrogenaceous fuel is introduced into the furnace bosh and the heated dried top gas is introduced into the lower half of the furnace stack above the furnace bosh at a point above which the coke in the furnace is not reactive.

Abstract: This method of preheating scrap iron mixed with plastic, rubber and resinous, i.e. organic, materials and intended for electric furnaces, in particular electric arc furnaces, is characterized by transforming the plastic, rubbery or resinous and like materials or organic nature present in the scrap iron, to advantageously eliminate them by a path able to produce thermal energy usable for preheating the scrap to be melted, said path consisting of pyrolysis in an environment fed both with the the scrap to be melted and with said organic materials, the whole being previously shredded.

Abstract: An improved FIOR processing plant and method for reducing raw iron ore fines into a 90+% metallized briquette product utilizing a multi-stage fluidized bed reactor in which the reducing and fluidizing gases are the products of partial combustion of methane with oxygen, the gases being introduced into an intermediate zone of the reducing tower above the stage or stages where final metallization occurs. Said processing plant including an ore preparation and feed assembly, a multi-stage reactor assembly, a briquetting assembly, a recycle and fresh reducing gas assembly, and, a heat recuperation assembly.

Abstract: A process for controlling the heating of a thin-walled body according to a predetermined temperature program by means of electrically controllable heaters, comprising: disposing the heaters adjacent one surface of the body such that each heater is in facing relation with a respective zone of the surface;supplying heat-generating power to each heater and monitoring the temperature at each surface zone; and for each zone:deriving (16,18,20), on the basis of the temperature values obtained in the monitoring step, estimated temperature values of the surface at successive time intervals each having a first selected duration;generating (28), on the basis of the estimated temperature values derived in each time interval, representations of the temperature, THSIFUT, which each surface zone will have, based on the level of power presently supplied to each heater, at a future time which is separated from the present time interval by a second selected duration;determining (30) the difference between THSIFUT and the desi

Abstract: An apparatus for a smelting reduction of iron ore comprising a preheat and prereduction furnace which preheats and prereduces iron ore, a smelting reduction furance into which said preheated and prereduced iron ore, carbonaceous material and fluxes are charged and in which said preheated and prereduced iron ore are smelted and reduced, a top blow oxygen lance having decarburizing nozzles and post-combustion nozzles and blowing oxygen into said smelting reduction furance, and at least one side tuyere placed at a side wall of the smelting reduction furnace and at least one bottom tuyere placed at a bottom of the smelting reduction furnace through which a stirring gas is respectively blown so that at least a part of said stirring gas introduced through said at least one side tuyere hits a swollen portion of the molten metal by said stirring gas introduced through said at least one bottom tuyere.

Abstract: The scrap that is to be charged into an electric arc furnace is preheated by a gas in a closed circuit and this gas is heated in a heat exchanger by the exhaust fumes from the furnace. A minor part of the circulating gas is continuously led off to a burner in which it is burnt with a gas as fuel at such a high temperature that rest products such as dioxines are destroyed. The exhaust fumes from the burner is supplied to the exhaust fumes of the furnace upstream of the heat exchanger. In another burner, another minor part of the circulating gas is continuously burnt with a gas fuel at a substantially lower temperature so that hydrocarbons in the circulating gas burn. The exhaust fumes from the burner are returned to the closed circuit.

Abstract: An apparatus for smelting reduction comprising a preheat and prereduction furnace for preheating and prereducing iron ores; a smelting reduction furnace into which iron ores, carbonaceous material and fluxing material are charged and in which the iron ores are smelted and reduced; a top-blow oxygen lance through which oxygen gas is blown into the smelting reduction furnace, having decarbonizing nozzles and post combustion nozzles; and the smelting reduction furnace having bottom and side tuyeres built respectively in a side wall and a bottom thereof.

Abstract: There is disclosed a process of recovering molten pig iron or steel pre-products from lumpy iron-oxide containing charging substances. The charging substances are reduced to sponge iron in a direct reduction zone, the sponge iron is smelted in a meltdown gasifying zone under supply of carbon carriers and oxygen-containing gas forming a coal fluidized bed, and CO and H.sub.2 containing reduction gas is produced, which is injected into the direct reduction zone and reacted there. For the commercial utilization of low-quality scrap grades, such as, e.g., automotive scrap,(a) scrap is charged into the meltdown gasifying zone in addition to sponge iron,(b) the scrap has an apparent weight of between 300 and 1000 kg/m.sup.3, preferably between 400 and 600 kg/m.sup.3, and(c) the temperature of the coal fluidized bed is maintained at 1,500.degree. to 1,7800.degree. C.

Abstract: Method and apparatus for recovering a metal from an ore by kinetic metallurgy as distinct from the usual static blast furnace approach.

Abstract: An improved method and apparatus for producing metallized iron or other metal by direct reduction of particulate metal oxide is disclosed. Spent reducing gas is recycled from a reduction furnace through a cooler-scrubber and a catalyst-containing stoichiometric gas reformer. In the cooler-scrubber, the spent reducing gas interacts with scrub water. Dust having an affinity for sulfur is recovered from the process and added to the scrub water causing sulfur in the spent reducing gas to form solids which precipitate and are removed as solid waste. Lowering the sulfur content of the spent reducing gas reduces the sulfur contamination of the catalyst and improves the efficiency of the process.

Abstract: There is described a mill for the production of steel from liquid and solid charging substances. It includes a coking plant, a blast furnace plant, a converter steelworks, and a plant for the direct reduction of iron ore. The converter steelworks is charged with molten pig iron from the blast furnace and with scrap as well as with sponge iron from the direct reduction plant. The reduction gas is composed of converter offgas, top gas and blast furnace gas. In order to avoid coal deposits in the direct reduction plant and to improve the composition of the reduction gas, the coke oven gas component is subjected to fractionation by alternating pressure adsorption so as to increase its portion of hydrogen and to lower its portion of hydrocarbons.

Abstract: An apparatus for producing cooling gas for a producer gas produced in a melt-down gasifier and surplus gas usable in an appropriate manner by cooling and cleaning at least part of the producer gas and the top gas of an iron ore reduction unit are proposed. The cooling gas is exclusively obtained by preparing producer gas. There is a cooling and a cleaning unit for the surplus gas and the cooling gas in each case. A constant gas flow is passed through the rear portion of the cooling and cleaning unit for the cooling gas with the aid of a constant volume blower. That part of the producer gas supplied to the cooling and cleaning unit for the cooling gas which exceeds this constant gas flow is passed into the cooling and cleaning unit for the surplus gas. The cooling and cleaning units can be constructed in two-stage manner, namely with in each case one packing washer (3 or 6) and a following adjustable Venturi washer (5 or 8).

Abstract: A method for two-stage melt reduction of iron ore, in which iron ore is prereduced substantially to wustite and at the same time melted down in a melting cyclone, and then liquid hot metal is produced in an iron bath reactor connected to the outlet of the melting cyclone and receiving the melted wustite by adding carbonaceous fuels and oxidizing gas to the melt. The resulting reaction gas from the melt is afterburned, and the dust-laden, partly burned reaction gases from the iron bath reactor are accelerated and further afterburned by adding a hot blast with a temperature of 800.degree. C. to 1500.degree. C., and at least a portion of such accelerated, after burned reaction gases are introduced into the melting cyclone to reduce and melt fresh iron ore.

Abstract: When operating mills including a coling plant, a blast furnace arrangement and a converter steelworks, large amounts of partially high-grade so-called cupola gases, such as coke oven gas and converter exhaust gases, form, which cupola gases, so far. In order to render these cupola gases utilizable at a better efficiency, thus reducing the specific energy consumption per ton of crude steel produced, and in order to be less dependent on external scrap, a plant for directly reducing iron ore is additionally adjoined to the mill. The ducts for the exhaust gas from the converters and the coke oven gas ducts from the coking plant are connected to a reformer to produce reducing gas substantially containing CO and H. The reformer is connected with the direct reduction plant via a reducing gas duct.

Abstract: In the operation of mills for the production of steel from molten pig iron and solid ferrous carriers, it is sought for economic reasons to increase the portion of solid ferrous carriers. To supply thermal carriers, such as fossile fuels, as is known, involves the disadvantages of extended charging times and of undesired accompanying elements introduced into the process.To avoid these disadvantages, the invention provides for a combination of at least one steel converter with a direct reduction plant, a meltdown gasifier and a cupola. Therein, sponge iron discharged from the direct reduction plant is melted to pig iron in the meltdown gasifier, on the one hand, and is used as solid charge for the converter. Scrap, together with coke, is melted in the cupola to blown metal, the latter, together with the pig iron produced in the meltdown gasifier, being supplied to the converter as liquid charge.

Abstract: An apparatus for the direct reduction of sulphurous iron ores with a shaft furnace, in which the ore is reduced in counterflow to the reducing gas is described, the waste gas being subdivided into two streams folllowing the furnace. One stream heats and desulphurizes the ore located above the shaft furnace in an ore bunker and is then supplied to the gas converter for heating purposes. The other stream, together with hydrocarbons, is supplied to a catalytic gas converter for producing reducing gas. The ore bunker is positioned above the shaft furnace and the ore outlet of the ore bunker is connected via downcomers with the ore inlet of the shaft furnace.

Abstract: In a method of producing a mixed gas from a process gas of a continuously working gasifier and a discontinuously incurred off-gas of an oxygen blowing converter, the off-gas of the refining process having the lower pressure is sucked into the process gas of the gasifier with the higher pressure via a gas jet ejector. The process gas serves as power gas, and subsequently the mixed gas is dedusted. A plant for producing steel includes a plant for recovering pig iron formed by a reduction shaft furnace and a melt-down gasifier, and at least one oxygen blowing converter for converting the pig iron into steel. The reduction shaft furnace has a process or top gas duct system, the converter has a converter off-gas duct, and an ejector connects both, the converter off-gas thus being feedable into the top gas duct system to form the mixed gas. Common dedusting and washing devices are provided for the mixed gas and safety devices for preventing oxygen from entering into the mixed gas.

Abstract: An apparatus for the direct reduction of sulphurous iron ores with a shaft furnace, in which the ore is reduced in counterflow to the reducing gas is described, the waste gas being subdivided into two streams following the furnace. One stream heats and desulphurizes the ore located above the shaft furnace in an ore bunker and is then supplied to the gas converter for heating purposes. The other stream, together with hydrocarbons, is supplied to a catalytic gas converter for producing reducing gas. The ore bunker is positioned above the shaft furnace and the ore outlet of the ore bunker is connected via downcomers with the ore inlet of the shaft furnace.

Abstract: A furnace for melting metals, in which the heating of the metal to be molten takes place at least partly by conducting hot gases along this metal. Means are provided for recycling the hot gases through the furnace chamber. The gases are either combustion gases of a burner disposed in the furnace chamber, or an inert gas heated outside the furnace chamber.

Abstract: A metal melting furnace equipped with a preheating tower having a plurality of fork-shaped shelf-plates extending into the inside thereof, comprising a gas mixing chamber provided in the lower end portion of the tower, communicating with the upper portion of the melting furnace, a duct for circulating combustion exhaust gas from the top portion of the tower into the gas mixing chamber, a damper arranged in the duct for controlling the amount of the combustion exhaust gas circulated into the gas mixing chamber, and a plurality of nozzles connected to the duct and opening into the gas mixing chamber.

Abstract: In a method of producing a mixed gas from a process gas of a continuously working gasifier and a discontinuously incurred off-gas of an oxygen blowing converter, the off-gas of the refining process having the lower pressure is sucked into the process gas of the gasifier with the higher pressure via a gas jet ejector. The process gas serves as power gas, and subsequently the mixed gas is dedusted. A plant for producing steel includes a plant for recoverng pig iron formed by a reduction shaft furnace and a melt-down gasifier, and at least one oxygen blowing converter for converting the pig iron into steel. The reduction shaft furnace has a process or top gas duct system, the converter has a converter off-gas duct, and an ejector connects both, the converter off-gas thus being feedable into the top gas duct system to form the mixed gas. Common dedusting and washing devices are provided for the mixed gas and safety devices for preventing oxygen from entering into the mixed gas.

Abstract: Method and apparatus for producing liquid iron from iron oxide, wherein the iron oxide is substantially converted to sponge iron by passing reducing gas through it in a reduction column and is then melted in a melt vessel which is in open communication with the reduction column by heat generated by reaction of oxygen-containing gas and carbonaceous material which reaction provides said reducing gas. To improve control of the process, the oxygen-containing gas and the carbonaceous material are respectively substantially pure oxygen and coal powder which are delivered separately into the melt vessel, and the liquid iron bath in the melt vessel is stirred so as at least partly to be kept in motion. By separate control of the oxygen and coal supplies, e.g. the level and/or direction of delivery, and by control of stirring, it is possible to control the ratio of CO and CO.sub.2 in the reducing gas and also the heat output in the melt vessel.

Abstract: A method for preventing deposits or build-ups of dust in off-gas channels for dust-containing off-gases from electrothermal smelting furnaces. This is done by blowing an additional gas tangentially into the furnace off-gas channels at the positions where build-ups or deposits of dust normally occurs. Hence a gas spiral is provided between the inner wall of the furnace off-gas channels and the dust-containing, hot furnace off-gas. Recirculated and cooled furnace off-gas is preferably used as additional gas. For open furnaces where the furnace off-gas is completely combusted before it enters into the furnace off-gas channels, air can be used as additional gas. The temperature of the additional gas is preferably kept below the sintering temperature of the dust in the furnace off-gas.

Abstract: A furnace arrangement utilizes a single vertically disposed shaft furnace incorporating the features of pellet drying and hardening, oxidizing heat-up, reducing roast and gas separation. The upper portion of the furnace dries and hardens "green" pellets while at the same time subjecting them to an oxidizing atmosphere and temperature increase. A stack of the pellets slowly moves downwardly through a transistion zone to a reducing atmosphere in a lower portion of the furnace. A heated reducing gas circulates through this lower portion and out of the furnace through a recovery system of the furnace arrangement. After the sublimate carried by the reducing gas is removed, the reducing gas is supplemented and returned to the lower portion of the furnace to again produce a reducing atmosphere. A smaller branch of cooled reducing gas enters the lower portion of the furnace adjacent the bottom to cool the pellet residue immediately prior to removal from the furnace.

Abstract: A method for forming a reducing gas in a molten metal bath gasifier and simultaneously directly reducing iron oxide in a shaft furnace with the gas thus produced, wherein the bath coolant is preferably provided by cleaned recycle gas from the direct reduction shaft furnace.

Abstract: A system for providing thermal and chemical energies for the production of pelletized iron ore concentrates while allowing a reduction of a portion of the material in process. The material in process is introduced as ore fines, pelletized and fired in an indurator to produce feedstock for reduction by further processing. A portion of the material in process is diverted to a reduction plant. The reduction plant provides thermal and chemical energies for the indurator. In a preferred embodiment, a low temperature plasma generator is employed, either as the reduction plant or to provide thermal and chemical energies for reduction. When a distinct reduction plant is employed, top gases from such plant may be supplied to the indurator to provide thermal and chemical energies therefor and to the plasma generator for recarburization thereof. The material in process may be diverted as ore fines or as fired or unfired pelletized ore concentrates.