Abstract: A process for sintering metal-containing materials, such as iron ores or manganese ores, on a sintering machine including a sintering belt for transporting the sinter mix during sintering thereof. The sintering belt has first, second and third portions. Sintering waste gas from the third portion is transported to and unified with sintering waste gas from the first portion in a mixing region to form a mixed gas, wherein the transporting distance of the sintering waste gas from the third portion to the mixing region is greater than the transporting distance of the sintering waste gas from the first portion to the mixing region. An apparatus for carrying out the process is disclosed, including the sintering belt, suction boxes operative at the portions of the belt, and lines for conveying the gas produced and the gases used in the process.

Abstract: A process for direct smelting metalliferous feed material in a direct smelting vessel and producing process outputs of molten metal, molten slag, and an off-gas from the vessel is disclosed. The process includes controlling pressure in the direct smelting vessel by controlling off-gas pressure in an off-gas stream supplied to a fluidised bed pretreatment apparatus while the process is operating in the “hold” and “idle” process states.

Abstract: In a system for processing metal, a furnace is provided which receives the metal being processed. At least one heating burner is provided in the furnace together with at least one atmosphere burner of substantially a same construction as the heating burner. An exhaust of the atmosphere burner at least partially provides an atmosphere within the furnace for the metal processing. An exhaust of the heating burner is separate from the exhaust of the atmosphere burner. A fuel feed for the atmosphere burner and a fuel feed for the heating burner are each separately controllable.

Abstract: A direct smelting process for producing molten metal from a metalliferous feed material in a direct smelting vessel is disclosed. The process includes using a stream of off-gas from the vessel as a fuel gas in (i) stoves for generating a hot blast of air or oxygen-enriched air for the process and (ii) a waste heat recovery apparatus for generating steam for the process. The process also includes controlling pressure in the vessel by controlling pressure in the off-gas stream while the process is producing molten metal.

Abstract: The invention relates to a gas quenching method of the type that makes use of (i) a quenching cell (V1) which is intended to receive objects to be quenched with a quenching gas and (ii) a buffer capacity (V2) which is designed to contain the quenching gas.

Abstract: A direct reduction process for producing direct reduced iron (DRI) in a reduction reactor having a reduction zone for reducing iron-oxides-containing particles, such as iron ore pellets, to DRI by reaction of said iron oxides with a high temperature reducing gas, and a cooling zone for lowering the temperature of the DRI produced in said reduction zone, wherein a stream of cooling gas, usually natural gas, is circulated through said cooling zone, a portion of said cooling gas is withdrawn from the cooling zone, cooled and cleaned in a gas cooler and a portion of the cooled gas is recycled to said reduction zone by means of an ejector utilizing the high-pressure natural gas make-up feed as the ejector's motive fluid. Using an ejector for recycling the cooling gas instead of using a mechanical compressor provides significant savings in electricity and in capital, operational and maintenance costs.

Abstract: Apparatus and process for producing metal products, in which a metal-containing charge material is melted in a melting unit, and a working gas, in particular an at least partially reducing working gas, is additionally produced in the melting unit. The working gas produced is extracted and if appropriate after cleaning, is used as a carrier gas, at least in part for—preferably pneumatic—transport of an at least partially reduced metal-containing material in the form of fine particles.

Abstract: The present invention provides a reducing furnace of the rotary hearth-type and a method for reducing a metal oxide simplified in the process from dehydration to molding, according to which a moisture-rich powdery raw material is reduced at low cost. The present invention also provides an operation method whereby dusts or sludge generated in the refining or processing of metal are economically recycled. A powdery mixture having a moisture content of 100% or higher relative to the total mass of a metal oxide-containing powder and a carbon-containing powder is made into a slurry and mixed by stirring. Thereafter, the slurry is dehydrated to a moisture content of 16 to 26% and compression-molded into articles. The cylindrical or granular shaped articles having a thickness or diameter of 30 mm or less thus obtained are fed to a zone the atmospheric temperature of which is 1170° C. or lower in the furnace and reduced through calcination by a rotary hearth reducing furnace thereby to provide a metal.

Abstract: A method of producing reduced metals is disclosed in which a mixture of a metal oxide and a reducing agent is heated by a burner such that the metal oxide is reduced to a reduced metal. Dry-distilled gas generated during carbonization of an organic matter-containing component is used as fuel for the burner. The sensible heat of exhaust gas evolved by the burner is utilized as heat for carbonizing the organic matter-containing component. Carbide derived by carbonizing the organic matter-containing component is used as the above reducing agent. This method yields excellent cost performance. An apparatus for reducing metal oxides is also disclosed.

Abstract: A method is disclosed for preheating a metal strip in at least one direct fired preheating section of a furnace for limiting the oxidation of the metal strip. The method includes installing burners in the preheating section along its length for establishing a plurality of preheating sub-zones of unit length corresponding to one burner. The air and fuel settings for each burner are adjusted in accordance with a desired heat demand. Subsequent steps include operating a variable number of downstream burners at full power to establish a preheating zone of variable length to produce the desired heat demand, and extinguishing a second variable number of upstream burners to establish a corresponding variable recovery zone.

Abstract: The invention relates to a steelmaking thermal energy recovery system. The steelmaking thermal energy recovery system comprises a steelmaking waste flue gas, a calcinable material, and a kiln. The steelmaking waste flue gas provides at least a portion of the thermal energy to the kiln for calcination of the calcinable material.

Abstract: In a method of producing direct reduced iron with use of a coal-derived gas, coal is heated to lower the moisture thereof, and the moisture-lowered coal is gasified in a coal gasification furnace to produce a coal-derived gas containing a reducing gas. The reducing gas is then utilized to reduce iron ore in an iron ore reducing furnace. With use of an exhaust gas from the iron ore reducing furnace, the coal is heated in the step of heating coal.

Abstract: In a process for the direct reduction of particulate iron-oxide-containing material by fluidization, a synthesis gas is introduced as a reducing gas into several fluidized bed zones consecutively arranged in series. The reducing gas is conducted from one fluidized bed zone to another fluidized bed zone in counterflow to a flow of particulate iron-oxide containing material through the fluidized bed zones. In order to reduce operating costs and, in particular, the energy demand, various process parameters are varied according to the temperature of the iron-oxide-containing material in the first fluidized bed zone being adjusted to be below 400° C. (and, preferably, below 350° C.), above 580° C. (and preferably about 650° C.), or to a temperature within the range of from 400° C. to 580° C. If the temperature of the iron-oxide-containing material in the first fluidized bed zone is maintained to be below 400° C.

Abstract: Apparatus for the direct reduction of mineral iron comprising a vertical reduction furnace (10) of the type with a gravitational load to achieve therein reduction reactions of the mineral iron, means (11) to feed the mineral iron into the furnace (10) from above, means to raise the temperature of a reducing gas, mixing means suitable to obtain a mixture of the reducing gas with at least a hydrocarbon, means to inject the mixture of high temperature gas, and means to remove (15) the reduced mineral from the lower part of the furnace (10), the furnace (10) being provided with at least two zones (12, 14), arranged vertically distanced, in each of which a mixture of high temperature gas is suitable to be introduced so as to achieve the reduction reactions in a controlled manner.

Abstract: A method of producing reduced metals is disclosed in which a mixture of a metal oxide and a reducing agent is heated by a burner such that the metal oxide is reduced to a reduced metal. Dry-distilled gas generated during carbonization of an organic matter-containing component is used as fuel for the burner. The sensible heat of exhaust gas evolved by the burner is utilized as heat for carbonizing the organic matter-containing component. Carbide derived by carbonizing the organic matter-containing component is used as the above reducing agent. This method yields excellent cost performance. An apparatus for reducing metal oxides is also disclosed.

Abstract: A combustion apparatus comprises a pair or more than two pairs of burner groups. Each burner group comprises one regenerator per a plurality of burners. In each pair of burner groups, a first burner group and a second burner group are fired alternately and waste heat produced when the first burner group is fired is stored in a regenerator of the second burner group. The stored waste heat is utilized to preheat the combustion air of the second burner group when the second burner group is fired. Similarly, waste heat produced when the second burner group is fired is stored in a regenerator of the first burner group, and the stored waste heat is utilized to preheat the combustion air of the first burner group when the first burner group is fired.

Abstract: A two-stage fluidized bed reducing apparatus and a reducing method for fine iron ore of a wide particle size distribution with an increased degree of utilization of the reducing gas. Fine iron particles dropping through the holes of a gas distributor can be recycled into the fluidized bed furnace, thereby preventing an impediment of the reducing gas flow due to abnormal defluidizing or channeling. A first fluidized bed furnace dries, pre-heats and pre-reduces the fine iron ore, and a second fluidized bed furnace finally reduces the pre-reduced iron ore. Downstream of the respective fluidized beds are installed intermediate hoppers and gas/solid sealing valves. Thus, the fine iron ore particles which drop through the holes of gas distributors during the abnormal operation are recycled to the furnaces. Accordingly, the gas flow is not impeded.

Abstract: An apparatus for producing reduced iron dries agglomerates, pelletized from a powdery mixture of an iron oxide powder and a reducing agent, in a drying chamber, preheats the dried agglomerates in a preheating chamber, and then reduces the preheated agglomerates in a high temperature atmosphere of a reducing furnace. In the preheating chamber, an off-gas from the reducing furnace is convected to preheat the dried agglomerates. A decrease in the fuel cost, and downsizing of the equipment can be achieved by effective use of the sensible heat of the off-gas discharged from the reducing furnace. Moreover, a downsized, simplified system for treatment of the off-gas is realized by decreasing the amount of the off-gas.

Abstract: A process to optimize the reduction process with a given quality of ore. The reduction gas 7 is analyzed by means of gas sensor 1 and is separated into two partial flows. The throughput of the partial flow which is oxidized is regulated by a regulation valve 3 and is then sent to the burner 4 where it is oxidized. The other partial flow of the reduction gas [7] is regulated by a regulation valve 2 according to the required amount of gas in the shaft and is thereafter brought to the required temperature in the heat exchanger 11 and mixed with the oxidized partial flow of the reduction gas. The gas components are determined by a gas sensor 13 and, when necessary, a gas delivery 14 is adjusted according to mathematical formulations. This makes it possible it possible to run the reduction process in the direction of its stoichiomeric optimum using a given quality of ore.

Abstract: The present invention relates to a method and apparatus for separating undesired toxic metals, such as Zn, Pb and Cd, from iron-containing materials by: sintering a mixture of such materials (typically including EAF dust and mill scale) with carbonaceous particles to form sturdy sinter lumps; preheating such lumps in a non-reducing atmosphere, if needed, to achieve an elevated temperature generally above the vaporization temperature of the undesired metals, but below the sticking temperature of iron-containing lumps (which is typically below the vaporization temperatures of such undesired metals in their oxide form), feeding the lumps at such elevated temperature into a reduction reactor; flowing hot reducing gas through lumps to volatilize undesired reduced metals and carry the volatilized metals out of reduction reactor leaving the iron-containing lumps largely stripped of the undesired metals and ready for discharge and safe and/or useful disposal or re-use, and finally cooling the off gas from the reactor

Abstract: In a method for producing a hot CO- and H2-containing reducing gas serving for the reduction of fine-grained metal ore, in particular iron ore, the reducing gas is formed in a gasification zone by a gasification of carbon carriers, in particular coal, taking place under the supply of oxygen and subsequently is cooled down to a reducing-gas temperature favorable to the reduction process. In order to produce a thermodynamically more stable reducing gas, the reducing gas by the addition of H2O and/or CO2—in order to prevent the Boudouard and heterogeneous water-gas reaction and a resultant heating of the reducing gas—is converted to a reducing gas that is thermodynamically more stable at the reducing-gas temperature.

Abstract: A two-chamber furnace for smelting scrap aluminum which is contaminated, has a distillation chamber above the first furnace chamber functioning as a charging stack and separated from the first chamber by a slider or flap arrangement. Flue gas from the first chamber is forced through the distillation chamber to destructively distill off the contaminants. The hood of the distillation chamber is equipped with a pressing body to compact the charge.

Abstract: An apparatus and a method for manufacturing molten pig iron by using a fine iron ore are disclosed. Coal is used to produce a reducing gas, and a fine iron ore is used to produce a molten iron and a reduced iron in a simple and efficient manner. The apparatus for manufacturing a molten iron by directly using coal as the fuel is as follows. A high temperature reducing gas is sent from a melter-gasifier to a fluidized bed lime stone calcining furnace to calcine the lime stone. The reducing gas is supplied to a second fluidized bed reducing furnace so as to manufacture a reduced iron directly. An off-gas from the second fluidized bed reducing furnace is supplied to a first fluidized bed reducing furnace (disposed above the second fluidized bed reducing furnace) to pre-heat and pre-reduce the fine iron ore. The calcined lime stone and the finally reduced iron are supplied to a melter-gasifier to manufacture a molten pig iron.

Abstract: A method of producing metals and metal alloys from metal oxides is disclosed. The method comprises the steps of partially pre-reducing the metal oxides to a pre-reduction degree of at least 60% in one or more pre-reduction stages. Thereafter, the method comprises completely reducing the metal oxides and melting the metal in a smelt reduction stage. The method is further characterized by carrying out at least one of the pre-reduction stages with one or more of natural gas, reformed natural gas, and partially reformed natural gas as a source of reductant.

Abstract: In a process for producing molten pig iron or steel preproducts from fine-particulate iron containing material in a meltdown gasifying zone of a melter gasifier, under the supply of carbon-containing material and oxygen-containing gas at the simultaneous formation of a reducing gas in a bed formed of solid carbon carriers, the iron-containing material is melted when passing the bed.

Abstract: In a method for producing liquid pig iron or liquid steel pre-products from charging substances comprising iron ore, preferably in lumps or pellets, and optionally fluxes. The charging substances are directly reduced to sponge iron in a reduction zone (12) and the sponge iron is melted in a melt-down gasifying zone (8) under the supply of carbon carriers and oxygen-containing gas. CO-and H2-containing gas is introduced into the reduction zone (12) and is reacted there. An export gas is withdrawn and conducted to a consumer (20). The export gas is subjected to CO2 removal or partial combustion and the resulting gas with CO2 is introduced back into the reduction process. This is done to keep down the carbon carriers having high portion of Cfix as well as consumption of O2.

Abstract: A method for producing a hot CO- and H2-containing reducing gas utilized for the reduction of lumpy metal ore, in particular iron ore, which comprises forming the reducing gas in a gasification zone by the gasification of carbon carriers, in particular coal, taking place in the presence of a supply of oxygen and subsequently cooling the reducing gas down to a reducing-gas temperature favorable to the reduction process, wherein H2O and/or CO2 is added to a reducing gas which has been subjectged to a cooling operation that does not effect an addition of H2O/CO2 in order to prevent the Boudouard and heterogeneous water-gas reaction and a resultant heating of the reducing gas, wherein the reducing gas is converted to a reducing gas that is thermodynamically more stable at the reducing-gas temperature.

Abstract: With a method for producing liquid metal from charging substances containing ore and of fluxes, the ore is directly reduced to sponge metal in at least one reduction zone (5, 7, 8), the sponge metal is melted along with fluxes in a melt-down gasifying zone (11) under the supply of carbon carriers and an oxygen-containing gas. A CO- and H2-containing process gas serving as a reducing gas is produced, fed into the reduction zone (5, 7, 8), reacted there, and subsequently withdrawn, wherein slagforming fluxes, in particular calcium carbonate, dolomite etc., gas are calcined by the process gas in a calcining zone (26′) that is separate from the reduction zone (5, 7, 8) and melt-down zone (11). To be able to employ slagforming fluxes of any desired grain and without disturbances of the reduction process, the calcining zone (26′) is connected in parallel to the reduction zone (5, 7, 8) with respect to the material flow and the calcined fluxes are fed into the melter gasifier (10) directly.

Abstract: An apparatus for manufacturing molten iron by using a calcination furnace, and a manufacturing method therefor are disclosed. A high temperature reducing gas (1000 to 1100° C.) from a melter gasifier is used as a calcination heat in a calcination furnace so as to cool the high temperature reducing gas to the optimum reduction temperature (800 to 850° C.), and so as to supply the cooled reducing gas to a shaft furnace, whereby the manufacture of the molten iron can be efficiently carried out, and a high thermal efficiency is realized even without a separate gas cooling device. Therefore, a separate cooling device for cooling the hot reducing gas of the melter gasifier is not required. Further, the hot reducing gas is naturally cooled at the calcination furnace, and therefore, the thermal efficiency of the hot reducing gas of the melter gasifier is maximized. Further, a separate water-using cooler and a separate compressor are omitted, and therefore, the molten iron manufacturing facility is simplified.

Abstract: The invention relates to a process for the reduction of metal-oxide-bearing material, particularly of iron ore, in a reduction vessel (1), wherein the metal-oxide-bearing material is charged from a vessel (2) for the metal-oxide-bearing material into the reduction vessel (1) and reduced therein by means of a reduction gas flowing counter currently to the metal-oxide-bearing material and wherein waste reduction gas discharged from the reduction vessel (1) is used for preheating the metal-oxide-bearing material in the vessel (2) for metal-oxide-bearing material, which is characterized in that the waste reduction gas discharged from the reduction vessel (1) is combusted and that a gas seal (16) is operated with the combusted waste reduction gas, which is located between the reduction vessel (1) and the vessel (2) for metal-oxide-bearing material, whereby the reduction vessel (1) is sealed against the vessel (2) for metal-oxide-bearing material (FIG. 1).

Abstract: The invention relates to a reduction vessel (1) for the reduction of metal-oxide-bearing material, particularly of iron ore, by means of a reduction gas flowing countercurrently to the metal-oxide-bearing material, which reduction vessel (1) is provided with an inlet (5) for the metal-oxide-bearing material, an inlet (6) for the reduction gas, an outlet (7) for off-gas and an outlet (8) for reduced material, downstream of which outlet (8) a lower sealing leg (9) is connected, a supply line (10) for a first sealing gas being provided at the lower sealing leg (9) in order to seal the reduction vessel (1) against the environment, characterized in that at least one additional supply line (12) for an additional sealing gas is provided at the lower sealing leg (9) , the additional supply line (12) being located downstream of the supply line (10) for the first sealing gas, seen in the direction of flow of the reduced material (FIG. 1).

Abstract: A method and a plant for reducing iron ore to pig iron in a blast furnace with the use of carbon, wherein a partial quantity of the carbon is admixed to the iron ore in the form of coke which ensures that the bulk material column is loosened and supported and that the gas can penetrate through the bulk material column in the blast furnace, and wherein the remaining partial carbon quantity is injected as a substitute reducing agent into the blast furnace. Prior to being injected into the blast furnace, the entire partial carbon quantity forming the substitute reducing agent is converted into a low-nitrogen reducing gas by gasification in a gasification reactor arranged spatially separate from the blast furnace.

Abstract: A melt-reducing facility for directly producing molten iron or molten pig iron by throwing iron bearing material, carbon material and flux into furnace bodies and blowing pure oxygen and/or an oxygen-rich gas therein, wherein a waste heat boiler and a power-generating facility are connected to a plurality of furnace bodies through ducts which can be freely opened and closed, the waste heat boiler being capable of recovering by vaporization the sensible heat and the latent heat of the combustible gases generated from the furnace bodies.

Abstract: A method and apparatus for increasing the productivity of an existing direct reduction iron (DRI) plant without increasing its reformer capacity existing in the plant. This object is achieved by not only recycling some effluent gas of the reduction reactor to the gas reformer (with natural gas or the like added with an oxidant as make up gas), but also recycling an additional portion of the effluent gas with added natural gas and an oxygen containing stream directly to the reducing gas stream exiting the reformer prior to or as part of its introduction to the reduction reactor, thereby providing additional reducing agents and increasing the reducing capacity of the plant. The oxygen containing stream is preferably added to the recycled reducing gas without preheating. Any excess or purged effluent gas is as usual burned as fuel.

Abstract: The present invention is an integrated process and apparatus for supplying at least a portion of the reducing gas feedstock to a reduction reactor, such as a reactor for the direct reduction of iron, wherein the reducing gas contacts a feed material at a mean operating gas pressure and effects reduction of the feed material to provide a reduced product. The integrated process includes gasifying a hydrocarbonaceous feedstock in a partial oxidation reaction to produce a synthesis gas which comprises hydrogen, and carbon monoxide at a pressure substantially greater than the mean operating gas pressure in the reduction reactor. The synthesis gas is expanded to lower its pressure to substantially the mean operating gas pressure in the DRI reduction reactor to thereby form the reducing gas feedstock at the pressure conditions used for the DRI reaction.

Abstract: In order to preheat pieces of iron scrap of various sizes and shapes highly effectively while avoiding the fusion of the pieces of iron scrap, a rotary kiln type preheating furnace and a shaft type preheating furnace are arranged in parallel with each other in the front stage of a melting furnace in which iron scrap is melted, and preheated iron scrap is charged from both preheating furnaces into the melting furnace. A damper is provided between the shaft type preheating furnace and the melting furnace, so that exhaust gas discharged from the melting furnace is prevented from directly flowing into the shaft type preheating furnace and introduced into the rotary kiln type preheating furnace. Exhaust gas which has passed through the rotary kiln type preheating furnace is introduced into the shaft type preheating furnace preferably from an upper portion and discharged from a lower portion.

Abstract: A 3-stage fluidized bed type iron ore reducing apparatus having X shaped circulating tubes is disclosed for forming a gas pore fluidizing layer of a fine iron ore, and for drying/pre-heating it to reduce it, so that the gas utilization rate and the reducing rate can be improved, as well as decreasing the gas consumption rate.

Abstract: Method and apparatus for the production of prereduced iron ore, Direct Reduced Iron (DRI), or the like, in an ironmaking plant wherein the reducing gas utilized in the chemical reduction of iron oxides is generated from natural gas within the reduction reactor system by reforming the hydrocarbons with such oxidants as water and oxygen inside the reduction reactor which under steady state conditions contains metallic iron which acts as a reformation catalyst. The amount of carbon in the DRI can be reliably controlled by modifying the relative amounts of water, carbon dioxide and oxygen in the composition of the reducing gas fed to the reduction reactor. The amount of carbon in the DRI is controlled by the amount of water in the reducing gas fed to the reduction reactor while the addition of oxygen provides the energy necessary for such DRI carburization.

Abstract: The invention provides a novel preheating apparatus and method for preheating a ferrous scrap mixture prior to feeding the scrap into a metallurgical furnace, primarily using heat recovered from hot waste gases emitted from the furnace exhaust port, and simultaneously reducing contaminants from the scrap and from the waste gases, with concurrent downward flow of hot waste gases and downwardly descending scrap. The apparatus has a chamber, including a top compartment with a cold scrap input for depositing cold scrap into the top compartment and a hot waste gas inlet in flow communication with the furnace exhaust port. The chamber also has a bottom compartment with a heated scrap discharging mechanism for force delivering the heated scrap into the furnace and a waste gas outlet in flow communication with a vacuum exhaust for evacuating spent waste gas.

Abstract: A continuous heat treating furnace in which heat is efficiently recovered from the combustion exhaust gas from the heating section of a continuous annealing furnace. The continuous annealing furnace of the metal strip is a heating furnace or a heating device provided with plural burners for heating to a predetermined temperature a steel material or a continuously supplied metal strip by means of combustion of the burners; a regenerative heat exchanger for collecting a sensible heat of a combustion exhaust gas of the burners, reserving the heat in a regenerator and supplying a predetermined gas to the regenerator to recover the heat to the predetermined gas; and a preheating section for blowing the predetermined gas from the regenerative heat exchanger to the metal strip for preheating. The heat exchanger body is divided into at least three sections, each section having a regenerator.

Abstract: The invention relates to a method to produce steel from a ferrous material, by using one furnace divided into, at least, two vessels which are connected to each other at least by ducts for the off-gases and ducts for the melted metal.

Abstract: In a process for the production of molten pig iron or molten steel pre-products and sponge iron from charging materials consisting of iron ore and, if desired, fluxes, direct reduction of the charging materials to sponge iron is carried out in a fixed-bed reduction zone, the sponge iron is melted in a meltdown gasifying zone under supply of carbon carriers as well as an oxygen-containing gas and a CO- and H.sub.2 -containing reducing gas is produced which is fed to the reduction zone, is reacted there and is drawn off as an export gas, and the drawn-off export gas is subjected to CO.sub.2 elimination and for the production of sponge iron is along with part of the reducing gas formed in the meltdown gasifying zone as an at least largely CO.sub.2 free reducing gas conveyed to a further reduction zone for the direct reduction of iron ore.

Abstract: An electric arc furnace comprises a closed melting vessel and includes means for charging metal to be molten into the melting vessel. At least one electrode extends into the melting vessel and generates an electric arc and forms a molten metal bath. At least one oxygen lance can be extended into the melting vessel for injecting oxygen into the molten metal bath and create a reaction where the carbon monoxide is generated. Gas is exhausted from the melting vessel and the carbon monoxide gas concentration of the exhaust gas is measured. A post combustion chamber receives the exhaust gas and provides post combustion of the exhaust gas. Post combustion oxygen is injected into the melting vessel in an amount sufficient to provide post combustion based on the amount of oxygen necessary for post combustion of the exhaust gas and the post combustion chamber.

Abstract: A sintering plant includes an apparatus for transporting sinter material along a sintering section through at least one first zone in which the sinter material heats to a low temperature, and through a second zone in which the sinter material heats to a high temperature. Discharge lines are provided along the sintering section. A dioxin catalytic converter for exhaust gas is provided in the discharge lines disposed along the second zone or directly downstream thereof. In this manner, catalytic breakdown of dioxins can be achieved even in the exhaust gas of a sintering plant, which has not been possible heretofore.

Abstract: A process for producing molten pig iron uses direct reduction of iron ore in a pre-reduction stage followed by a final reduction stage. In the pre-reduction stage iron ore is pre-reduced in a melting cyclone by means of a reducing process gas originating from the final reduction stage. A post-combustion occurs in the reducing process gas in the melting cyclone so that said iron ore in said melting cyclone is at least partly melted. The partly melted iron ore passes downwardly into a metallurgical vessel situated beneath the cyclone in which the final reduction takes place by supply of coal and oxygen, thereby forming a reducing process gas. A partial post-combustion occurs in the reducing process gas in the metallurgical vessel by means of said oxygen supplied thereto. The post-combustion ratio of the gas on exiting the metallurgical vessel is not more than 0.55.

Abstract: In a process for producing molten pig iron or liquid steel pre-products, from particulate iron-oxide-containing material by fluidization, the iron-oxide-containing material is prereduced in at least one prereduction stage (7) by aid of a reducing gas and subsequently is reduced to sponge iron in a final reduction stage (8), the sponge iron is melted in a meltdown-gasifying zone (11) under the supply of carbon carriers and an oxygen-containing gas, and a CO- and H.sub.2 -containing reducing gas is produced which is introduced into the final reduction stage (8), is reacted there, is drawn off, subsequently is introduced into a prereduction stage (7), is reacted there, is drawn off, subjected to scrubbing and subsequently is carried off as an export gas and wherein at least a portion of the reacted reducing gas is purified from CO.sub.2, is heated and is used as a recycle-reducing gas for the reduction of the iron-oxide-containing material.

Abstract: A device for three-stage fluidized bed for reducing a fine iron ore in accordance with the present invention comprises: a first single-type fluidized bed furnace for drying/pre-heating a fine iron ore in a bubbling fluidized state; a first cyclone for collecting fine iron ore particles entrained in an exhaust gas from the first fluidized bed furnace; a second single-type fluidized bed furnace for pre-reducing the fine iron ore dried/pre-heated in the first fluidized bed furnace; a second cyclone for collecting fine iron ore particles entrained in an exhaust gas from the second fluidized bed furnace; a third twin-type fluidized bed furnace comprising a first cylindrical reaction furnace and a second reaction furnace for finally reducing coarse iron ore particles and medium/fine iron ore particles, respectively, which are pre-reduced in the second fluidized bed furnace; a third cyclone for collecting medium/fine iron ore particles entrained in an exhaust gas from the first reaction furnace of the third fluidize

Abstract: A direct reduction process is disclosed for iron oxide-containing materials. Synthesis gas is mixed with top gas produced during direct reduction of the iron oxide-containing materials and is used as reduction gas for directly reducing and heating the iron oxide-containing materials up to reduction temperature. In order to set the H.sub.2 S content at a predetermined value by a relatively simple technique and with a relatively simple equipment, at least part of the sulphur contained in the iron oxide-containing materials as H.sub.2 S produced during heating or direct reduction is added to the reduction gas together with the top gas.

Abstract: A direct reduction process is disclosed for iron-oxide-containing materials. Synthesis gas is mixed with top gas produced during direct reduction of the iron-oxide-containing materials and is used as reduction gas for directly reducing iron-oxide-containing materials. In order to avoid or reduce metal dusting caused by an increased CO content of the reduction gas with a simple technique and equipment, the CO/CO.sub.2 ratio of the reduction gas is set at a predetermined value from 1 to 3.

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.