Abstract: A method of heating a non-ferrous and/or ferrous metal-containing stock in a furnace with a heating chamber, a charging door, an exhaust stream port and an exhaust stream duct, which includes: a) introducing fuel and an oxygen-containing gas into the heating chamber of the furnace through a burner so that a flame is formed, b) monitoring the signal of at least one optical sensor installed within the heating chamber and/or the exhaust stream duct, c) monitoring the change of the temperature T of the exhaust stream with time (dT/dt), and d) adjusting the fuel:oxygen ratio in step a) as a function of the signal of the flame sensor(s) and dT/dt in the exhaust stream, and, an apparatus designed for implementing said method.

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 control method for melting a metal charge in a furnace comprising at least a hearth containing the metal charge and a roof. The method provides that the hearth is weighed by means of a plurality of weighing elements distributed along the perimeter of the base of the hearth, and that the values detected by the plurality of weighing elements are sent to a control unit in order to obtain information relating to the distribution of the metal charge inside the hearth.

Abstract: A method of suppressing slag foaming that can grasp a state of slag foaming in the continuous melting furnace and accurately suppress the slag foaming so as to enable continuous production of molten metal in a stable state. This method includes charging of a suppressor into slag in the furnace, measuring a flow rate of a flue gas discharged from the continuous melting furnace during blowing of the slag over time, increasing a charging speed rate of the suppressor if the flue gas flow rate has an increasing tendency and decreasing the charging speed rate of the suppressor if the flue gas flow rate has a decreasing tendency.

Abstract: In a method of regulating the output of CO in steel production, oxygen is introduced into a melt to remove carbon present, the actual value of the carbon stream evolved from the melt is determined, the intended value of the evolved carbon stream derived from the amount of oxygen introduced and the carbon content of the melt is calculated, intended and actual values are compared with one another and if the actual value is below the intended value, measures for preventing boiling are undertaken.

Abstract: The invention relates to a method for processing aluminum in a furnace consisting in introducing an aluminum-containing material and possibly one or several types of salt into the furnace, melting said material by heating with the aid of at least one burner supplied with a combustive material and fuel in such a way that a molten aluminum possibly covered with a slag containing, in particular alumina and at least one salt is produced and in measuring a carbon monoxide and/or hydrogen concentration in the furnace atmosphere or in a smoke at the exit of the furnace. Oxygen content in the combustive material supplying at least one burner is greater than 10% by volume, preferably greater than 21% by volume.

Abstract: Nickel entrained in the sulphide mineral pyrrhotite is engineered to dissolve in leaching acid in a two step procedure. First, a slurry of the mineral and the acid is activated by oxidation. This is done in a time T1 by electrolysis; or alternatively chemically, by adding e.g an oxidizing acid to the mineral. After activation, the slurry is then kept under anoxic conditions for a time T2. During T2, the sulphide starts to dissolve much more rapidly, and the rapid breakdown of the sulphide enables the nickel to dissolve and thus to be leached out of the mineral. The dissolved nickel is extracted from the leaching acid e.g by electro-winning.

Abstract: Methods for treating aluminum in a furnace. An aluminum charge is introduced into a furnace and melted with heat from at least one burner. The burner is supplied with at least one oxidizer and at least one fuel. The oxidizer is made up of at least 10% oxygen by volume. The concentration of a first gas is measured in the furnace atmosphere or in a flue gas exiting the furnace. The oxidation of the molten aluminum is then reduced by holding the flow rate of the oxidizer steady while varying the flow rate of the fuel, according to the concentration of a second gas in the furnace or in the flue gas exiting the furnace. The concentration of the second gas is determined by comparing the measured species concentration and the intrinsic concentration which would be present absent the aluminum charge.

Abstract: A process and a device for melting aluminum where solid aluminum is melted in a furnace to form aluminum melt pool. The temperature and carbon monoxide (CO) concentration of the flue gas generated in the melting process is detected and examined for variations. Using this variation information, it is determined if aluminum oxides have formed on the surface of the aluminum melt pool and if they have, the melting process is regulated accordingly.

Abstract: A smelting reduction method comprising (a) charging a carbonaceous material and an ore into a reacting furnace to directly contact the carbonaceous material and the ore; (b) reducing the ore until at least a part of the ore is metallized, the resultant reduced ore containing at least a part of metallized metal being produced; (c) charging the carbonaceous material and the ore containing at least a part of the metallized metal from step (b) into a smelting furnace having a metal bath; and (d) blowing a gas containing 20% or more of oxygen into the metal bath in the smelting furnace to produce molten iron.

Abstract: A description is given of a method of optimizing the design and operation of a reduction process for iron-containing charge materials (3), preferably in lump form, in a reduction shaft (1) to which reduction gas (9) is fed, for example from a fusion gasifier (6), with a reduced product (13), for example iron sponge, being taken from the reduction shaft (1) for the production of liquid pig iron or liquid primary steel products, in which method the reduction process is described by means of a mathematical-physical-chemical process model, the reduction shaft (1) is modelled multi-dimensionally, in particular three-dimensionally, and the process model is numerically evaluated and the results of the evaluation, obtained as multi-dimensional, in particular spatial, distributions of physical or chemical variables, are taken into account for the reduction process. This allows the reduction process to be quantitatively assessed in the entire reduction shaft and, as a result, the reduction process can be optimized.

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 method uses a mobile waste heat treatment furnace to treat wastes generated in geographically separated two or more places, with the treatment being carried out in these places where the wastes are generated. Alternatively, the mobile waste heat treatment furnace is used to treat the wastes after these wastes have been moved to a properly built station. An improved heat treatment method for treating a waste is provided. The method permits heat treatment to be carried out in a relatively small scale, and can effectively treat wastes discharged from various types of plants.

Abstract: The state of slag foaming generated in an electric furnace steel manufacture is judged by measuring the NOx amount in exhaust gas. The foaming state is adjusted to completely interrupt the contact of melted steel with air so that low nitrogen of the steel is always achieved or reduction of electric power consumption rate is achieved. Thus, in the manufacture of steel by subjecting iron scrap to dissolving, refining and heating stages successively in an electric arc furnace, the NOx amount in the exhaust gas is measured at the refining and heating stages of the melted steel and then the state of the slag foaming is judged depending upon the measured data.

Abstract: The invention concerns a low pressure for the preparation of an iron-based, optionally alloyed powder comprising the steps of preparing a raw powder essentially consisting of iron and optionally at least one alloying element selected from the group consisting of chromium, manganese, copper, nickel, vanadium, niobium, boron, silicon, molybdenum and tungsten; charging a gas tight furnace with the powder in an essentially inert gas atmosphere and closing the furnace; increasing the furnace temperature; monitoring the increase of the formation of CO gas and evacuating gas from the furnace when a significant increase of the CO formation is observed and cooling the powder when the increase of the formation of CO gas diminishes.

Abstract: Method for controlling a smelting reduction process, in particular a cyclone converter furnace process for producing pig iron, characterized in that one: measures the carbon fraction C in the off-gas in the form of CO and Co2O; measures the hydrogen fraction H2 in the off-gas in the form of H2 and H2O; determines the C/H2 ratio in the off-gas; compares the C/H2 ratio thus determined in the off-gas against the C/H2 ratio prevailing for the coal being supplied, and adjusts the coal supply based on the difference found in the C/H2 ratios in the off-gas and the coal being supplied.

Abstract: An apparatus and method for reclaiming contaminated scrap metal, more particularly an improved reverberatory furnace designed for melting scrap. The amount of hydrocarbons volatilized from the melting of contaminated scrap is measured and the fumes are passed into the main hearth for burning. As the amount of fuel value contained within the fumes increases, the amount of fuel provided to the burner is proportionally reduced while the amount of oxygen is kept constant. This will ensure that the amount of fuel and the amount of oxygen present within the furnace is completely burned without excessive free oxygen or unburned fuel building up within the furnace or furnace exhaust. The burner will be operating under lean fuel conditions or under fuel rich conditions such that the flame temperature is lower than at stoichiometric firing, whereby the burners create reduced NOx.

Abstract: The present invention refers to a method for determination and control of the amount of nitrogen dissolved in metallic liquid phases and to a device permitting, when placed in the steel producing plant and for instance in the tundish or in the continuous casting mold, the determination of nitrogen content directly from the liquid phase. Such a device can point out possible nitrogen pick-up in real-time, thus permitting to immediately intervene.

Abstract: A process of producing molten iron involves: a) introducing iron oxide, flux, oxygen, nitrogen, carbon, and hydrogen to a smelter reactor; b) maintaining conditions to cause (i) the iron oxide to be reduced, (ii) molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of foaming, FeO-containing slag, and (iii) carbon monoxide gas to rise through the slag; c) causing at least some of the carbon monoxide to react with the oxygen; d) releasing an offgas containing CO, CO2, H2, and H2O; and e) removing at least some of the molten iron and slag from the reactor. Good process stability is achieved by: f) repeatedly measuring, during the process, the conditions of the slag height, the temperature of the molten iron, the levels of CO, CO2, H2, and H2O in the offgas, the carbon level in the molten iron, and the FeO level in the slag, and g) subsequently adjusting one or more process variables (e.g.

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 method for processing metal chips and/or metal dust, including a first process step in which the metal is moistened and fed by a conveyor system to a collecting tank, especially a settling tank. In further process steps the material being processed passes from the collecting tank into a buffer tank, and from the buffer tank it is proportioned to a dewatering apparatus. In the dewatering apparatus the moisture is removed by compressed air. Removed moisture is fed back into the scraper flight conveyor settling tank, and then the dewatered metal is transferred to a container.

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 vacuum plant, in particular for secondary metallurgy, having at least one ejector which is in communication with a closed container within which a metallurgical vessel which is to be placed under pressure can be brought. A second ejector is connected in series with the one ejector via an intermediate condenser having a cooling water feed line and a condensate discharge line. A final condenser and a suction pump are connected to the second ejector. A controllable condensate distributor member is provided in the condensate discharge line of the intermediate condenser. One line of the distributing member is connected to a heat exchanger and the other line is connected to the cooling water supply of a final condenser.

Abstract: Disclosed herein is a method of sequentially and continuously determining the concentrations of carbon, hydrogen, and nitrogen in molten steel using a single apparatus. Disclosed also herein are a method and an apparatus for determining trace amounts of carbon in molten steel which are the specialized application of the principle used for the above-mentioned method.

Abstract: A process for smelting iron-containing source material in a reactor containing a slag bath, includes generating heating and reducing conditions in at least one reducing region of the bath by injection of fuel/reductant and oxygen-containing gas by at least one top submerged lance. The source material is fed to the reactor together with additional reductant and with flux at or adjacent the at least one reducing region so as to be subjected to smelting reduction, using coal as the additional reductant. The rates of injection of oxygen and fuel/reductant are controlled to achieve required and sufficient reducing conditions by providing the injected gas with an oxygen content from about 40% to about 100% sufficient for a degree of combustion of the fuel/reductant of from about 40% to about 50%. The CO and H.sub.

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: The present invention relates to a method for monitoring and control of smeltmetallurgical processes, endothermic as well as exothermic ones, preferably pyrometallurgical processes, by means of optical spectrometry, whereby one first determines for each endothermic and exothermic smeltmetallurgical process and/or process step characteristic emissions or absorptions and identifies the atomic or molecular origin of the emissions/absorptions, that one during a running process records changes in the characteristic emissions/absorptions and relates these changes to the condition of the process and with reference hereto controls the process.

Abstract: A method for controlling the magnesium content of molten aluminum includes the steps of injecting a halogen gas into the molten aluminum, sampling a portion of the resulting gases evolved from the molten aluminum, detecting the presence of constituents in the sampled gases and/or characteristics of the sampled gases indicative of the imminent evolution of unreacted halogen gas, and adjusting the rate of halogen gas injection to approach the point where unreacted halogen gas is about to be evolved. In the preferred embodiment, the halogen gas is chlorine; the detected constituents are gaseous hydrogen chloride (CHl) and aluminum chlorhydrate compounds (Al.sub.2 Cl.sub.x .multidot.(OH).sub.6-x); and the detected characteristic is the opacity of the sampled gases. The invention includes a technique for adjusting the rate of halogen gas injection so as to approach the optimal rate. The invention also includes (1) a sensor for detecting the content of HCl and Al.sub.2 Cl.sub.x .multidot.(OH).sub.

Abstract: Pyrogenic processes in which gas or fume is evolved are monitored by impinging a beam of X-rays (3) from an X-ray source (1) on the gas or fume whereby radiation is produced by the X-ray fluorescence which is detected by a radiation detector (7) and analyzed by an analyzer (8) for the various constituent elements. In this way the progress of the metallurgical process can be monitored and the information used for process control.