Abstract: A process for converting organic wastes into a reducing agent-coke substitute (“RACS”). More specifically, a process for producing a reducing agent-coke substitute from a mixed waste material containing economically recoverable metals and organic based materials is described. In accordance with one aspect, the process comprises blending mixed waste material with a metal-containing smelter by-product, processing the blend of mixed waste material and smelter by-product through a heated mixing device to convert the blend into reducing agent-coke substitute.

Abstract: A method of reduction treatment of metal oxides characterized by using as a material a powder containing metal oxides and containing alkali metals and halogen elements and further, in accordance with need, carbon, mixing the material with water to produce a slurry, then dehydrating this and charging the dehydrated material, mixed with another material in accordance with need, into a rotary hearth type reduction furnace for reduction.

Abstract: In a method for producing pig iron using iron ore with a high content of zinc, a blast furnace raw material 2 is produced using iron ore with a high content of zinc which contains 0.01 mass % or more of zinc and 50 mass % or more of iron, pig iron is produced by charging the blast furnace raw material 2 into a blast furnace 1 and, at the same time, zinc-containing dust 4 in a blast furnace discharge gas is recovered, and zinc 6 is recovered from the zinc-containing dust 4 using a reduction furnace 5. A mixed raw material into which the zinc-containing dust 4, a carbonaceous solid reducing material and a slag-making material are mixed is preferably charged on a movable hearth, and the mixed raw material is preferably reduced by supplying heat from an upper portion of the movable hearth so as to recover zinc 6 while producing reduced iron 7.

Abstract: A process for recovering non-ferrous metals, in particular copper, nickel and cobalt, from metallurgical residues containing these non-ferrous metals at an oxidation state of greater than or equal to zero, in an alternating current type plasma arc electric furnace comprising a plurality of electrodes, containing a liquid copper heel covered by a fluid slag comprising at least one fusion-reduction phase, comprising charging of metallurgical residues comprising the non-ferrous metals onto the heel contained in the plasma arc electric furnace, fusion of the metallurgical residues in the fluid slag or at the slag-metal bath interface, reduction of at least the non-ferrous metals to oxidation state zero, and intense stirring of the copper heel by injection of inert gas, preferably nitrogen and/or argon, so as to avoid crust formation and to accelerate the reduction reaction and to cause the copper-miscible non-ferrous metals to pass into the copper heel.

Abstract: A method of alleviating dust in the early stages of metal ore processing, such as copper ore, through mining the ore through concentration involves spraying and wetting crushed ore rock and ground particles and dust at least several of a series of locations with a dust suppressant containing major amounts of water plus minor amounts of an additive combination of glycerol and a selected non-ionic surfactant, and passing the wetted particles and dust to a metal concentrator where the additive combination does not interfere with metal concentration yield.

Abstract: A metallurgical process involves providing an ingredient enclosure and placing a plurality of granules of a first material in the ingredient enclosure. The first material contains a first ingredient in a metallurgical process. A metallurgical process furnace having a chamber in which ingredients for the metallurgical process are added is provided and the ingredient enclosure and the first material are added to the chamber. The chamber is heated after the addition of the ingredient enclosure and the first material to the chamber, although it may also be heated prior to such addition. In one form, the granules comprise mill scale and the metallurgical process furnace is a blast furnace.

Abstract: Disclosed is a process and apparatus for the treatment of divided metal residues contaminated by one or more organic compounds, including mixing, inside a chamber, of metal residues with at least one calcium/magnesium compound capable of reacting exothermically with water; exothermic reaction of the at least one calcium/magnesium compound with the water that the metal residues contain; rise in temperature of the metal residues subject to an exothermic reaction; dehydration of the metal residues during this exothermic reaction; oxidation of the organic compounds during the mixing, by bringing the metal residues contaminated by one or more organic compounds mixed with the at least one calcium/magnesium compound into contact with a gas stream containing at least partly oxygen; and removal from the chamber of a handleable dehydrated treated product having a residual content of organic compounds of less than 1% by weight of the treated product.

Abstract: A method of reduction treatment of metal oxides characterized by using as a material a powder containing metal oxides and containing alkali metals and halogen elements and further, in accordance with need, carbon, mixing said material with water to produce a slurry, then dehydrating this and charging the dehydrated material, mixed with another material in accordance with need, into a rotary hearth type reduction furnace for reduction.

Abstract: A raw material for sintering of 100% in total is blended so as to adjust iron-containing dust and/or sludge to 60% or more, and coarse grains having a grain size of 2 mm or larger to 20% or more on the weight basis, one-third or less of the total amount of addition of coke breeze is added as a fuel, the blend is kneaded and granulated using a vibration kneading granulator to thereby produce granulated grains, the residual portion of the total amount of addition of coke breeze is added to the granulated grains, the blend is subjected to exterior coating granulation using a rolling type granulator, thus-granulated raw material for sintering is screened, and a fraction having a grain size of 1 mm or larger is used for sintering, making it possible to sinter microparticulate dust and microparticulate sludge as main raw materials, which have conventionally been used only to a limited amount of use.

Abstract: This invention provides chemical processes for the treatment of industrial steelworks waste, especially those from an electric arc furnace, called “flue dust,” to allow for the subsequent recovery of metals (e.g. zinc and iron) from the dust. The main purposes of the process are: (i) the opening of the crystalline webs (zinc ferrite) originally formed in the flue dust, with the simultaneous production of soluble sulfates in aqueous medium; (ii) and the destruction of possible dioxins without subsequent regeneration. The processes encompass production of salts or sulfates of the metals in the flue dust, utilizing concentrated sulfuric acid and reagents or catalysts by dry medium, at normal pressure and moderate temperatures. The processes promotes reaction of sulfuric acid with elements found in the flue dust to maintain a homogenous mixture without the presence of water, and prevent agglomeration of the particles through the addition of secondary reagents and catalysts.

Abstract: The invention relates to a process for the separation and recovery of non-ferrous metals from zinc-bearing residues, in particular from residues produced by the zinc manufacturing industry. The process comprises the steps of: —subjecting the residue to a flash or agitated bath fuming step, thereby producing an Fe bearing slag and Zn- and Pb-bearing fumes; and —extracting the Zn- and Pb-bearing fumes and valorising Zn and Pb; characterised in that CaO, SiO2 and MgO are added as a flux before or during the fuming step so as to obtain a final slag composition with: formula (I) all concentrations being expressed in wt %. The invention also relates to a single-chamber reactor for Zn-fuming equipped with one or more submerged plasma torches as heat and gas sources. [ Fe ] [ SiO 2 ] + [ CaO ] [ SiO 2 ] + [ MgO ] 3 > 3.5 ; 0.1 < [ CaO ] [ SiO 2 ] < 1.

Abstract: A metallurgical process involves providing an ingredient enclosure and placing a plurality of granules of a first material in the ingredient enclosure. The first material contains a first ingredient in a metallurgical process. A metallurgical process furnace having a chamber in which ingredients for the metallurgical process are added is provided and the ingredient enclosure and the first material are added to the chamber. The chamber is heated after the addition of the ingredient enclosure and the first material to the chamber, although it may also be heated prior to such addition. In one form, the granules comprise mill scale and the metallurgical process furnace is a blast furnace.

Abstract: A method of operating a channel induction furnace so as to receive electric arc furnace (EAF) dust, basic oxygen furnace (BOF) sludge/dust and/or other iron and volatile metals containing materials as a feed stream on a batch, continuous or semi-continuous basis together with a iron-containing material feed, and therefrom produce an iron-containing hot metal or pig iron product while recovering iron value from the feed materials and recovering volatile metal components contained in the feed materials.

Abstract: Improved methods for treating metallurgical compositions involve reacting a metallurgical composition with an aqueous nitric acid solution. The reaction is performed at a pressure of at least about 220 psig and at a temperature of at least 100° C. The metallurgical composition comprises iron and one or more non-ferrous metals. The reaction dissolves the majority of the non-ferrous metal compositions into the solution which is in contact with solid ferric oxide. The reaction can be repeated on the isolated solids to increase the purity of ferric oxide in the solids. Zinc can be removed from the mixed metal solutions obtained from furnace dust by a variety of separation techniques.

Abstract: A method of operating mechanical separation devices at high temperatures to separate various volatile metals, metal halides and metal oxides to produce high purity materials.

Abstract: A method for the recovery of high purity zinc oxide products, and optionally iron-carbon feedstocks, from industrial waste streams containing zinc oxide and/or iron. The waste streams preliminary can be treated by adding carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedbacks. Once the zinc oxide has been recovered, the purification process is used to further purify the zinc oxide to obtain zinc oxide which is at least 99.8% pure and which has predeterminable purity and particle characteristics. Various zinc compounds may then be quickly, easily, and economically produced from this recovered zinc oxide.

Abstract: A method for the recovery of high purity zinc oxide products, and optionally iron-carbon feedstocks, from industrial waste streams containing zinc oxide and/or iron. The waste streams preliminary can be treated by adding carbon and an ammonium chloride solution, separating any undissolved components from the solution, displacing undesired metal ions from the solution using zinc metal, treating the solution to remove therefrom zinc compounds, and further treating the zinc compounds and the undissolved components, as necessary, resulting in the zinc products and the optional iron-carbon feedbacks. Once the zinc oxide has been recovered, the purification process is used to further purify the zinc oxide to obtain zinc oxide which is at least 99.8% pure and which has predeterminable purity and particle characteristics. Various zinc compounds may then be quickly, easily, and economically produced from this recovered zinc oxide.

Abstract: Liquor compositions for the extraction of metallic elements from a metal-contaminated starting material such as mineral ores, recyclable wastes, contaminated soils, toxic wastes such as dusts producing through steelmaking processes by effectuating preferably prolonged contacting of such starting material with the liquor to cause the underlying structure of the starting material to be broken down. The contaminated starting materials are more susceptible to metal separation because the released metallic element are readily solubilized in the contacting liquor. Compositions of the contacting liquor comprise caustic silicate solutions containing essentially saturating levels of silica. Once the plurality of metallic elements contained in the starting material have been solubilized, they tend to remain in solution, and then may be routinely extracted and removed using conventional extraction methodologies such as precipitation of insoluble salts, electrowinning, or electrodeposition.

Abstract: An improved method and apparatus for recovering metal values from Electric Arc Furnace dust, particularly zinc and iron values, by mixing EAF dust and carbonaceous fines to form a particulate mixture; heating the mixture at a sufficient temperature and for a sufficient time to reduce and release volatile metals and alkali metals in a flue gas; collecting the released metals, and removing the metal values from the process as product.

Abstract: Methods and apparatus for processing electric arc furnace (“EAF”) dust through a basic oxygen furnace (BOF) to recover iron value from the EAF dust and concentrate zinc from the EAF dust into a material useful as a feed in zinc manufacturing processes. The method results in the reduction of the burden for the regulatory tracking of EAF dust. In addition, the method provides economic savings which result from the reduction of processing fees and the recovery of the value of iron and zinc materials. The apparatus involves the use of existing equipment that is used to recover iron value from other materials generated at steel making facilities, or the installation of new equipment for the purpose of iron reuse.

Abstract: A continuous process and apparatus for transforming, by chemico-physical reactions inside molten slag, materials to be gasified, thermally destroyed, inertized, or from which elements of commercial value are to be recovered, yielding controlled composition products, in an apparatus made of a single reaction chamber, called reactor, having a substantially cylindrical symmetry, including two portions, a top and a bottom one, said process being characterised in that it comprises the steps of: introducing into the bottom portion of the reactor, sideways through a second injection level and/or vertically from the top thereof, the material to be transformed, the fuel, the comburent and possibly slag inoculants and additives and material-carrying gases; and tapping from the bottom portion of the reactor the transformed material, of controlled composition, and the inert slag.

Abstract: A method for treating steel works dust in order to recuperate elements capable of being upgraded. The method comprises attrition in water followed by hydraulic grading of the resulting load. The method is characterized in that is further comprises: a washing step to separate the water soluble saline fractions of the insoluble oxides; hot treatment to eliminate metals in the form of free oxides such as zinc and lead; treatment by heating at a temperature ranging between 240 and 800° C.; treatment with sulphuric acid having a concentration between 5 and 8%.

Abstract: The invention relates to a method of utilizing secondary raw materials containing iron, zinc and lead, preferably steelmaking dusts, in a rotary tubular furnace customarily equipped for the rolling process, with basically adjusted rolling slag. By reducing the portion of the carbon carriers in the burden, the energy balance of the rolling process is improved on one hand, and the throughput of the rotary tubular furnace used is increased on the other hand. By improving the quality of the rolling slag, the capability of utilizing the same is favored.

Abstract: A process for thermal treatment of residual materials containing heavy metal and iron oxide, including providing a multiple-hearth furnace having hearths provided one above the other, depositing the residual materials continuously on a top hearth of the hearths, gradually transferring the residual materials to lower hearths of the hearths, introducing reducing agents to at least one of the hearths and reacting the residual materials to form heavy metals and directly reduced iron, exhausting gases containing heavy metals from below hearths of the hearths where the heavy metals are being vaporised, re-injecting at least a part of the gases into the multiple-hearth furnace from above the hearths of the hearths where the heavy metals are being vaporised, and discharging the directly reduced iron together with residues of the reducing agents in an area of a bottom hearth of the hearths in the multiple hearth furnace.

Abstract: A method for reducing the formation of Zn(NH4)4Cl2 from ZnO/NH4Cl solutions formed during an industrial waste stream recycling method useful for the recovery of high purity zinc oxide products and other chemical and metal values from industrial waste streams.

Abstract: A method of processing flue dust, where the flue dust contains one or more compounds from a first group of zinc, lead and cadmium compounds, and contains one or more compounds from a second group of iron, silicon, calcium, magnesium and aluminum compounds, includes mixing the flue dust with a carbonaceous material, heating the flue dust/carbonaceous material mixture under non-turbulent conditions to cause a substantial portion of the compounds from the first group to become gas-borne while retaining a substantial portion of the compounds of the second group in a non-gas-borne condition, and separating the gas-borne compounds from the non-gas-borne compounds.

Abstract: The present invention relates to a process for treating fly ash/APC residues chlorides, sulphates, earth alkali metals selected from the group consisting of calcium, potassium, and sodium, and heavy metals selected from the group consisting of lead, which residues are obtained from air pollution control processes that utilize dry/semi-dry line injection, such that said residues may be disposed of as non-hazardous materials. The process comprises the sequential steps of: (a) washing and agitating the fly ash/APC residue (20) with water (50) to form a residue slurry containing solubilized lead salts and calcium chloride; (b) filtering (42) the residue slurry to remove a filtrate (46) having a pH of higher than about 11.8 and containing the solubilized lead salts and calcium chloride; and (c) recovering a first calcium enriched filter cake (44).

Abstract: A carbonaceous material is controlled such that the amount of carbon is from 7 to 60 mass % based on the total amount of iron and Zn in a starting mixture comprising one or more of ducts containing iron oxide and Zn oxide and a binder in an amount to bond the dusts, and water is added to prepare green pellets incorporated with the carbonaceous material. Then, dry pellets prepared by drying the thus prepared green pellets into a reduction furnace, the dry pellets are heated by heat transfer, mainly, radiation such that a temperature elevation rate is from 3 to 13° C./sec within a temperature range from 150 to 900° C. of the pellets, thereby reducing Zn oxide and evaporating Zn, as well as reducing iron oxide to produce reduced iron pellets.

Abstract: In a method of producing molten pig iron (13) or molten steel pre-products from charging substances formed of iron ore (4), preferably in the shape of lumps and/or pellets, and optionally of fluxes (5), the charging substances are directly reduced to sponge iron in a reduction zone (2), the sponge iron is charged into a melt-down gasifying zone (12) and, there, is melted under the supply of carbon carriers (10) and an oxygen-containing gas, wherein a CO—H2-containing reducing gas is generated that is withdrawn from the melt-down gasifying zone (12) and introduced into the reduction zone (2), is reacted there and is withdrawn as a topgas, wherein the topgas is subjected to scrubbing and the sludges thus separated are at least partially agglomerated. To utilize the agglomerates thus formed while expending as little energy as possible, the agglomerates are recirculated into the reduction zone (2).

Abstract: According to a process for producing pig iron (10) from fine-particulate iron oxide carriers and lumpy iron-containing material in a meltdown gasifying zone (9) of a melter gasifier (3), the iron-containing material is melted in a bed (13) formed of solid carbon carriers, under the supply of carbon-containing material and oxygen-containing gas while simultaneously forming a reducing gas. Fine-particulate iron-oxide carriers, such as iron-containing fine ore and ore dust and oxidic iron fine dust, are introduced into a reducing gas stream leaving the melter gasifier (3), and the reducing gas is separated from the fine-particulate material formed thereby. The separated fine-particulate material is introduced into the meltdown gasifying zone (9) via a dust recirculation line (26, 27, 28, 29) and through a dust burner (30), and the reducing gas is used for reducing iron-oxide-containing material.

Abstract: A continuous process for recovering vanadium values from petroleum coke is disclosed. A vanadium containing coke is charged to a molten metal bath to which oxygen containing gas is added in an amount sufficient to heat balance the process and produce off gas. The carbon in the coke dissolves in the molten metal bath as does the vanadium content of the coke. A majority, and preferably all, of the net addition of vanadium to the process is removed in the form of “dust” from the molten metal bath.

Abstract: A method of making a pneumatically injectable additive for an Electric Arc Furnace, the method comprising screening a waste material comprising oily millscale in water to form uniform particles, and then mixing those particles with carbon and lime; and storing the mixture in air permeable bags in a dry atmosphere until the mixture has chemically cured to form the injectable particles.

Abstract: A process for producing a foaming slag above a stainless steel melted in an electric furnace, in which: a powder containing at least one metal oxide and carbon in its composition is introduced into the slag, at least one oxide present in the powder is reduced by its reaction with the carbon to form in the slag bubbles composed of the metal of the metal oxide and of carbon monoxide, the bubbles present in the slag giving rise to a slag in the form of a stable foam.

Abstract: The invention concerns a method of treating electric arc furnace (EAF) dust. In the method the dust is preheated and decontaminated under conditions which oxidize the magnetite content of the dust to hematite. Thereafter the preheated and decontaminated dust is introduced into a fluidized bed reactor in which hematite is reduced, by means of a hot reducing gas generated by reforming natural gas in a non-catalytic plasma-arc heating process, to yield an iron-rich material suitable for recycling to the EAF, and a high grade zinc oxide product.

Abstract: Disposal of halogenated organic hazardous wastes by introducing them as feedstocks in the direct reduction of iron oxide (DRI). (DRI is described in Pat. RE.32247.) The novel hydrocarbons used as reducing feedstocks would normally be destined to become hazardous wastes or else their products of decomposition would be hazardous wastes. Such hydrocarbons are inclusive of but not limited to halogenated hydrocarbons such as PVC, PCBs, various insecticides, dioxin and others. This category of hydrocarbon wastes is otherwise difficult to utilize, incinerate, or otherwise dispose of safely. Polluting byproducts such as dioxin are almost always released. However within a DRI reactor they can be disposed of safely. There is no stack or vent to atmosphere. These hydrocarbons would be used as an alternative to or admixture with the usual hydrocarbon feedstocks of choice, methane or related short chain hydrocarbons.

Abstract: In a method for producing liquid pig iron (16) and a sponge metal from charging substances comprising iron ore (4) respectively metal ore, the charging substances are directly reduced to sponge iron in at least one first reduction zone (2) the sponge iron is melted in a melt-down gasifying zone (15) under the supply of carbon carriers (10) and oxygen-containing gas and a CO— and H2-containing reducing gas is produced which is fed to the first reduction zone (2), is reacted there and withdrawn as a top gas, wherein the withdrawn top gas after a scrubbing operation is subjected to CO2 elimination and optionally to heating and is supplied to at least one further reduction zone (27) for the direct reduction of metal ore, in particular of iron ore (26), as a reducing gas that is at least largely free from CO2 and after reaction with the metal ore (26) is withdrawn as an export gas and purified in a scrubber.

Abstract: A carbonaceous material is controlled such that the amount of carbon is from 7 to 60 mass % based on the total amount of iron and Zn in a starting mixture comprising one or more of ducts containing iron oxide and Zn oxide and a binder in an amount to bond the dusts, and water is added to prepare green pellets incorporated with the carbonaceous material. Then, dry pellets prepared by drying the thus prepared green pellets into a reduction furnace, the dry pellets are heated by heat transfer, mainly, radiation such that a temperature elevation rate is from 3 to 13.degree. C./sec within a temperature range from 150 to 900.degree. C. of the pellets, thereby reducing Zn oxide and evaporating Zn, as well as reducing iron oxide to produce reduced iron pellets.

Abstract: A process for at least partially reducing iron oxides comprises forming a bed of reactants on a hearth of a rotary hearth furnace, the reactants comprising (a) mixture of iron ore fines and particulate carbonaceous material and/or (b) micro-agglomerates of iron ore fines and particulate carbonaceous material. The mixture and/or the micro-agglomerates are heated in the rotary hearth furnace to at least reduce the iron oxides. The "micro-agglomerates" are agglomerates that are less than 1400 microns (and preferably more than 500 microns) in diameter. The at least partially reduced product is preferably used in the production of metallic iron. An apparatus for at least partially reducing iron oxides is also claimed. The process permits operation of the rotary hearth furnace without requiring pelletisation of iron oxides fines and coal.

Abstract: A treating method of recovering zinc in the metal state from a waste containing the zinc in the oxide state, lead, chlorine, fluorine, and water comprising a mixing process 90 of obtaining a to-be-treated mixed material 70 by mixing a steel dust 7 and a reducing material 8 together; a chlorine recovery process 91 of recovering the chlorine and the water by heating the to-be-treated mixed material 70; a lead recovery process 92 of recovering fluorine and lead by heating the to-be-treated mixed material 70 under vacuum; a zinc recovery process 93 of recovering metallic zinc by heating the to-be-treated mixed material 70 at a temperature higher than that in the lead recovery process 92 with the vacuum state maintained so as to reduce and vaporize zinc; and a residue recovery process 94 of recovering a residue 79 of the to-be-treated mixed material 70. This construction allows the metallic zinc to be recovered at a high purity from a zinc oxide-containing waste and an on-site treatment to be accomplished.

Abstract: The invention is directed to a process for dehydrating and recycling back into a BOF converter wet BOF scrubber sludge to produce a steelmaking revert having an improved flow rate when handled in a recycle stream. Wet sludge is combined with hot BOF slag to provide a slag/sludge mixture. The wet sludge causes the mixture to have a moisture content greater than 10% water by weight, and the hot slag, having a temperature below the molten liquid state, vaporizes the water in the mixture and reduces the moisture content to about 4% water by weight or less. The dehydrated mixture has improved flow rate properties when it is recycled as a steelmaking revert.

Abstract: A process of recovering iron values and separating zinc oxides and other contaminants from steel mill waste metal oxides, such as blast furnace dust, BOF dust, mill scale and oily sludges, characterized by iron metallization levels up to 95% or more and zinc oxide removal in excess of 99%, and including the steps of blending the oxides with coke breeze in an amount sufficient to provide a total carbon content of 16% to 22%, the coke breeze having a particle size of 50% or more plus 60 mesh or larger, briquetting the blend to form briquettes having a thickness ranging from 1/2" to 3/4", and firing the briquettes in a rotary hearth furnace to metallize the iron and evolve zinc and other oxide contaminants.

Abstract: A method for recovering zinc oxide comprises the steps of: agglomerating a dust; charging the agglomerate to a molten iron in a melting furnace; collecting a dust generated from the melting furnace; recycling a part of the collected dust and recovering another part of the collected dust. An apparatus for recovering zinc oxide comprises: an agglomeration unit for agglomerating a dust containing iron oxide and zinc oxide; a melting furnace for accepting the agglomerate and for holding the molten iron for reducing the dust; and at least two units of dust collector for collecting the dust containing zinc oxide generated from the melting furnace.

Abstract: The invention relates to a method for processing waste that contains contaminants. The contaminants may be metals modified by carbon, oxygen, phosphorus, or sulfur. The waste in the form of a powder is mixed with an ionic reducing agent in an inert liquid medium. The mixture is melted to give a first liquid phase and a second metal phase. The two phases are separated and solidified to enable disposal or temporary storage of the first liquid phase and to enable recycling of the second metal phase. The method is useful for inerting or reclaiming waste containing metal contaminants.

Abstract: A process for purifying waste gases from smelting, resmelting or combustion plant furnaces and the use of the filter dusts produced. The invention is used in particular in the production or preparation of nonferrous metals. According to the invention, at least one alkali compound, in particular NaHCO.sub.3, is injected dry, optionally in the presence of activated carbon and/or open hearth coke, into the waste gas leaving the production process. The separated filter dust is fed back to the smelting or combustion process. It has unexpectedly been found that the returned filter dust can lower the dioxin and furan contents of the crude gas. Owing to the composition of the filter dust, it can also be used as protective salt in secondary aluminum production.

Abstract: In a method for producing alloyed steels, wherein in a first manufacturing step iron carriers are to a great extent decarburized and dephosphorized by means of oxygen and after removal of the slag resulting therefrom the melt is adjusted to the desired alloy and carbon content in a further manufacturing step after addition of alloy carriers by means of oxygen and inert gas.Especially in order to produce stainless steels in an economical manner while achieving a high level of productivity, in particular while charging major amounts of solids,the first manufacturing step is carried out under supply of electric energy in an electric furnace andthe further manufacturing step is also effected under supply of electric energy, in an electric furnace that is to a great extent free from phosphorus-containing slag.

Abstract: A method for extracting metals from metal-containing materials, especially waste, by pyrohydrolysis. The metal-containing materials which contain at least one or more of the metals from the group consisting of Zn, Cd, Pb, Hg, Cu, Sn (as Sn(0) and Sn(II)), As, Sb, Au, Ag and Bi, are made to react at 700-1100.degree. C., advantageously 800-900.degree. C., with a gas composition which at least comprises 25-45% by volume of water vapor, 0-12% by volume of carbon dioxide, 2-20% by volume of hydrogen chloride, 0-15% by volume of carbon monoxide, the remainder being nitrogen and possibly oxygen. The metals from the above-mentioned group are extracted in the form of volatile metal chlorides.

Abstract: In a process for producing pig iron, nonferrous heavy metal alloys, ferrochromium carbure or carbon-free ferrochromium and synthetic blast furnace slags, using metal-oxide-containing waste incineration residues or slags, the charging materials of waste burning, e.g., car shredder light fractions and/or metallurgical dusts, are at least partially oxidized and subsequently are reduced while separating nonferrous metals or alloys, whereupon the oxidic slag phase depleted from metals or alloys is mixed with liquid steelworks slag optionally upon further addition of metallurgical dusts, whereupon crude steel is drawn off while lowering the viscosity of the steelworks slag and the remaining slag portion is subjected to further reduction while recovering pig iron and optionally Fe chromium alloys, whereupon the resulting synthetic blast furnace slag is discharged.

Abstract: A method is provided for improving the filtration rate of nonhazardous wastewater streams generated at a steel plant. The solids are concentrated in the wastewater stream. No more than about 5% by weight of lime is added to the concentrated wastewater stream which is then dewatered. A friable filter cake is produced by allowing the solids to harden. The lime addition results in a significant increase in the rate at which the stream may be filtered.

Abstract: A process is disclosed for working up combustion residues or slags from waste incineration plants or steel works slags in a converter by reacting the molten slag with a metal bath while injecting carbon and oxygen into the metal bath. The converter is subdivided into three adjacent openly communicating zones. An afterburning zone including at least one lance for afterburning directed onto the slag bath is arranged in the vicinity of the slag feed. The lance generates a circulating flow above the slag bath. Following the afterburning zone, a metal bath sump zone is formed for reacting the metal bath with the slag bath. Next, a settling zone is formed, from which the hot combustion gases and the slag melt are drawn off.

Abstract: A method for injecting fine iron ore in a smelting reducing process is disclosed, in which the carrier gas for the iron ore is the discharge gas from a melter gasifier without the need of separate carrier gas. It includes the steps of pre-reducing iron ore in a pre-reduction furnace, melting and reducing it in the melter gasifier, supplying the discharge gas from the melter gasifier through an ascending tube to a cyclone and to said pre-reduction furnace, directing the cooled and cleaned fine iron ore through a recycling system and a melting burner into the melter gasifier. A part of the discharge gas is supplied through a venturi scrubber, a first compressor and a circulating tube into an ascending tube. A part of the compressed gas circulating through the tube is recompressed by means of a second compressor and fine iron ore from a stored source is injected into ascending the tube by the recompressed gas by means of a pneumatic fine iron ore conveying system.