Abstract: The invention relates to a method for operating a furnace, wherein a starting material comprising at least one metal element is molten, wherein the starting material is heated by at least one burner that is operated with a fuel volume flow of a fuel and an oxidant volume flow of an oxidant. An exhaust gas temperature of the furnace is monitored in an exhaust gas line at least at one measuring point downstream of a post combustion zone, wherein in a standard operational state a target fuel volume stream and a target oxidant volume stream is fed to the burner, wherein a change of the exhaust gas temperature is recorded at predetermined time frequencies and is compared to a predetermined threshold value.

Abstract: A process for the production and/or treatment of at least one metal in a reactor includes discharging a waste gas stream via a waste gas conduit and after-treating the waste gas stream by supplying a cooling gas and/or a cooling gas mixture. The after-treating includes injecting the cooling gas and/or cooling gas mixture into the waste gas conduit on a side of the waste gas conduit facing the reactor, at a high velocity and substantially tangentially with respect to a main flow direction of the waste gas. A volume of the cooling gas and/or the cooling gas mixture injected into the waste gas conduit is adjusted so as to reduce a mixing temperature below a melting temperature of the molten particles and/or a condensation temperature of the vaporous constituents of the waste gas stream.

Abstract: The invention relates to a method for operating a furnace, wherein a starting material comprising at least one metal element is molten, wherein the starting material is heated by at least one burner that is operated with a fuel volume flow of a fuel and an oxidant volume flow of an oxidant. An exhaust gas temperature of the furnace is monitored in an exhaust gas line at least at one measuring point downstream of a post combustion zone, wherein in a standard operational state a target fuel volume stream and a target oxidant volume stream is fed to the burner, wherein a change of the exhaust gas temperature is recorded at predetermined time frequencies and is compared to a predetermined threshold value.

Abstract: To effectively separate and recover solid dust and volatile or molten components while preventing solid dust and volatile or molten component dust from being adhered to inner walls of a temperature control tower.

Abstract: A method for reducing metal oxides in a shaft furnace. A charge of metal oxide and a reductant is reacted in the furnace to produce a primary metal of the metal oxide and an additional secondary metal. The temperature of the off gas from the reaction is controlled to prevent condensing of the secondary metal so that it remains in the off gas for separation therefrom.

Abstract: In a temperature control device comprising a temperature control tower for controlling a blown high-temperature exhaust gas to a proper temperature and discharging the temperature-controlled exhaust gas to the subsequent step side, the temperature control tower comprises a cooling water spray means for spraying cooling water to about the center of the gas flow of the high-temperature exhaust gas and a cooling gas injecting means for injecting cooling gas along the inner wall of the temperature control tower.

Abstract: An improved method and apparatus for increasing the productivity of a direct reduction process in which iron oxide is reduced to metallized iron by contact with hot reducing gas; comprising the steps of: a) providing a first hot reducing gas consisting essentially of CO and H2; b) providing additional reducing gas by reaction of a gaseous or liquid hydrocarbon fuel with oxygen; c) mixing the first hot reducing gas with the additional reducing gas to form a reducing gas mixture; d) enriching the reducing gas mixture by the addition of a gaseous or liquid hydrocarbon; e) injecting oxygen or oxygen-enriched air into the enriched mixture; and f) introducing the enriched mixture into an associated direct reduction furnace as reducing gas.

Abstract: A device for producing sponge iron from iron oxide lumps consists of a reduction shaft in which a hot dust laden reducing gas is delivered. The gas is produced in a gas generator by means of partial oxidation of solid carbon carriers and passes into the lower end of the reduction zone via lateral reduction gas inlets. The iron oxide lumps are fed to the upper area of the reduction shaft and are radially fed as sponge iron to the lower end of said reduction shaft via delivery organs. The delivery organs are arranged in such a manner that the sponge iron is conveyed only radially outwardly.

Abstract: A process and apparatus for continuously reducing carbon monoxide (CO), uncombined free hydrogen (H2) and volatile hydrocarbons (VOC's) in molten metal refining vessel off-gases without forming undesirable oxides of nitrogen. Off-gases are directed to a reaction chamber wherein CO, H2 and VOC's are oxidized at a controlled temperature and with a controlled quantity of O2 So as to realize substantially total oxidation of gases present with minimized formation of oxides of nitrogen. Volume and energy of treated gases directed for baghouse treatment are reduced in comparison with prior practice.

Abstract: The present invention relates to a high energy-saving process for preheating and final reduction of directly reduced iron (DRI) to be conveyed to a melting process, by using melting furnace off-gas, which is characterized by a high temperature and a high CO-content.

Abstract: An improved method and apparatus for increasing the productivity of a direct reduction process in which iron oxide is reduced to metallized iron by contact with hot reducing gas; comprising the steps of: a) providing a first hot reducing gas consisting essentially of CO and H2; b) providing additional reducing gas by reaction of a gaseous or liquid hydrocarbon fuel with oxygen; c) mixing the first hot reducing gas with the additional reducing gas to form a reducing gas mixture; d) enriching the reducing gas mixture by the addition of a gaseous or liquid hydrocarbon; e) injecting oxygen or oxygen-enriched air into the enriched mixture; and f) introducing the enriched mixture into an associated direct reduction furnace as reducing gas.

Abstract: The invention relates to a device comprising a fusion gasifier and a reduction shaft arranged thereabove and for reduction of iron ore in spongy iron. The spongy iron is introduced through horizontal discharge devices in the lower section of the reduction shaft, and a pipe connection is introduced into the head section of the fusion gasifier where it is melted using a oxygen-containing gas and gasifying means also conveyed into the head of the fusion gasifier, and is reduced to liquid crude iron. A reduction gas is produced at the same time which is conveyed out of the head of the fusion gasifier. The discharge devices lead into a dust-blocking container arranged in a lower section of the reduction shaft and to which the pipe connection leading to the fusion gasifier is attached.

Abstract: A process for producing iron carbide in a fluid bed reactor in which the pressure may be maintained in excess of the pressure at which the mole fraction of hydrogen in the process gas begins to decrease. The hydrogen concentration is increased above the equilibrium concentration for hydrogen at the temperature and pressure in the reactor. Further improvements are gained by preheating a iron ore reactor feed in which the iron oxide is primarily in the form of hematite under a reducing atmosphere, and using at least two fluid bed reactors in series.

Abstract: A cupola emission control system is provided that includes both improved physical emission control equipment and improved controls for operating such equipment. The physical emission control improvements include an orifice ring of restricted diameter above the cupola main afterburners to improve the turbulence of the air in the upper cupola area to allow improved combustion of carbon monoxide. Further, twin venturis are provided with improved air passage control equipment to affect the temperature in the upper cupola combustion area. Further, an improved control system is provided whereby actual time calculations are made for remaining emission permitted amounts of certain pollutants, mainly carbon monoxide, and real time adjustments are made for cupola operation to assure compliance with such permitted emission limits.

Abstract: A process of smelting iron that comprises the steps of:a) introducing a source of iron oxide, oxygen, nitrogen, and a source of carbonaceous fuel to a smelting reactor, at least some of said oxygen being continuously introduced through an overhead lance;b) maintaining conditions in said reactor to cause (i) at least some of the iron oxide to be chemically reduced, (ii) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (iii) carbon monoxide gas to rise through the slag;c) causing at least some of said carbon monoxide to react in the reactor with the incoming oxygen, thereby generating heat for reactions taking place in the reactor; andd) releasing from the reactor an offgas effluent,is run in a way that keeps iron losses in the offgas relatively low. After start-up of the process is complete, steps (a) and (b) are controlled so as to:e) keep the temperature of the molten iron at or below about 1550.degree. C.

Abstract: A process for producing iron carbide in a fluid bed reactor in which the pressure may be maintained in excess of the pressure at which the mole fraction of hydrogen in the process gas begins to decrease. The hydrogen concentration is increased above the equilibrium concentration for hydrogen at the temperature and pressure in the reactor. Further improvements are gained by preheating a iron ore reactor feed in which the iron oxide is primarily in the form of hematite under a reducing atmosphere, and using at least two fluid bed reactors in series.

Abstract: A process for producing pig iron from iron ores involves the iron ores traveling from the top downwards through a reduction unit via a succession of oblique trays which are staggered in a cascade-like manner. A hot reduction gas containing carbon monoxide and hydrogen flows from the bottom of the reduction unit upwards. A reduction product is drawn off at the bottom end of the reduction unit and is fed to a unit for further treatment thereof. A reduction gas is generated in a gas generator by partial oxidation of carbon carriers or by cracking of natural gas or petroleum. Iron ores having at least a high proportion of dust-like and/or fine granular iron ores are sorted into fractions according to grain size and introduced into the reduction unit in such a way that the course fraction of the iron ore is introduced into the top section of the system and the fine fraction of the iron ore is introduced into the middle zone or into the middle and bottom zones of the system.

Abstract: For heating sponge iron to temperatures of about 850.degree. C. without substantial oxidation losses, there are provided at least two separate preheating stages at different temperatures, to which the sponge iron is successively fed and in which the temperature and the gas atmosphere are respectively individually controlled in such a way that a chemically neutral gas atmosphere is set in the first preheating stage at the lowest temperature and a reducing gas atmosphere is set in the last preheating stage at the highest temperature. The hot gas for the preheater is obtained at least in part from the waste gas from the melting furnace, to which the preheated sponge iron is fed.

Abstract: Metal vapor, for example zinc fume in the offgas of a smelting furnace, is captured by bringing the stream into direct contact with a fluidized bed of solid particles having a particulate loading of greater than 10 kg/m.sup.3 and preferably greater than 400 kg/m.sup.3. The thermal mass and temperature of the bed is such as to rapidly quench the vapor in the case of zinc from above 960.degree. C. to below 419.degree. C. in less than 100 milliseconds, whereby the vapor condenses in the bed and is recovered as zinc metal in acceptable yield.

Abstract: Inference is carried out through intermediate hypotheses representing physical states of a blast furnace using HG (Heuristic Grade) in order to comprehensively diagnose the state of the furnace to ascertain optimum actions. Specific parameters are monitored to immediately recognize a transition of conditions inside the furnace to additionally execute the inference. Various types of actions such as defensive actions and offensive actions are covered in this inference. A burden distribution estimation model considering collapse of a coke bed is used for calculating distribution inside the furnace to aid in deciding on an optimum action when an action to alter distribution in the furnace is required as the result of the inference. Creation and alteration of a knowledge base for the inference are carried out without interrupting the inference.