Abstract: The present invention relates to a zero-waste process for extraction of alumina from different types of bauxite ores and red mud residues and of titanium dioxide from ilmenite. Iron oxide is first reduced to metallic iron above the melting point of C-saturated cast iron alloy which yields a high-C iron alloy and an Al and Ti metal oxide rich slag which is then treated with alkali carbonate to form alkali aluminates and titanates. The alkali aluminates are separated by water leaching from which the hydroxide of alumina is precipitated by bubbling C02. The residue from water leaching is treated with sulphuric acid and Ti02 is precipitated via a hydrolysis route. The process recovers most of the metal values and generates only small quantities of silicious residues at pH 4-5 which can be used for soil conditioning.

Abstract: A process for treating base metal smelter slag containing from about 20 to about 60 percent by weight iron and at least one further metal selected from the group consisting of nickel, copper and cobalt comprises mixing base metal smelter slag with calcium sulphate and carbon and melting the resultant mixture to produce a metallic sulphide matte containing substantially all the further metal or metals and a secondary slag substantially free of the further metal or metals suitable for use as a cement.

Abstract: A method for treating a raw steel plant slag to transform it into a hydraulic binder at least equivalent to a Portland cement clinker, comprises the following steps: oxidizing treatment with input of oxygen, air or a mixture thereof at a pressure ranging between 1 to 15 bars, at a temperature ranging between 1650 and 1400° C., of raw steel slag containing, relative to the raw slag total weight, at least 45 wt. % of CaO and less than 30 wt. % of Fe2O3; and adding to the slag a lime source optionally with silica and/or alumina, so that the slag, after tranformation and at room temperature, has a propotion of Fe2O3 of less than 13 wt. % and a mineralogical composition comprising at least 40 wt. % in C3S mineralogical phase and more than 10 wt. %, of calcium ferrite, relative to the final slag total weight.

Abstract: A process for treating a raw steel industry slag, for converting same into a hydraulic binder at least equivalent to a Portland cement clinker, comprising:

Abstract: A process that produces pozzolanes, synthetic blast furnace slags, belite, or alite clinkers, as well as pig iron alloys, from oxidic liquid slag. The oxidic liquid slag is reduced above an iron bath in a reactor containing submerged tuyeres. Carbon is blown through the submerged tuyeres and into the iron bath to maintain the iron bath at a carbon content of between 2.5 wt % and 4.6 wt %.

Abstract: The invention relates to a process for producing directly reduced iron, liquid pig iron and steel, in which charge materials, which are formed from iron ore, preferably in lump and/or pellet form, and, if appropriate, additions, are reduced directly, in a first reduction zone, to form iron sponge, the iron sponge is smelted in a melter gasifier zone supplied with carbon carriers and oxygen-containing gas, to form liquid pig iron, and a reduction gas is generated, which gas, after off-gas cleaning, is introduced into the first reduction zone, where it is converted and drawn off as top gas, and in which process the top gas is subjected to off-gas cleaning, if appropriate is fed to a further reduction zone for direct reduction of iron ore to form iron sponge and, following reaction with the iron ore, is drawn off as export gas and is subjected to off-gas cleaning, and in which process the liquid pig iron and, if appropriate, the iron sponge from the further reduction zone are fed to a steelmaking process, in par

Abstract: In a method of converting slags derived from nonferrous metallurgy, in particular primary and secondary Ni and Cu metallurgical slags, while recovering and/or enriching the nonferrous metals and forming synthetic puzzolans, the molten oxidic slags are reduced with gases containing H2 and CO such as, e.g., cracked gas in a first reduction stage above a metal bath containing Cu and/or Ni and optionally Co. The redox potential of the CO/H2 mixture is reduced by adding 10 to 40% by volume H2O vapor and/or CO2 in order to hold off the reduction of Fe oxides. Subsequently, the remaining slag free of Cu and Ni is further reduced above an iron bath while using carbon in order to reduce the portion of Fe oxides so as to produce a slag free of Fe and nonferrous heavy metals.

Abstract: In a process for dechroming, and/or depleting the MgO content of, steel slags, oxygen is introduced into the liquid steel slag to an extent sufficient for converting iron quantitatively to iron oxide and at least 5% by weight of the iron oxide contained in the slag to iron-III-oxide. The oxidized slag obtained solidifies and is disintegrated, whereupon the paramagnetic portions formed are magnetically isolated and separated from the dechromed slag.

Abstract: A method for processing solid waste incineration residues is disclosed in which the residues are introduced a steelworks slag bath in a sufficient amount so that the residues constitute from 15-45% by weight of the combined weight of the solid waste incineration residues and the steelworks slag bath. The residues are melted to effect the evaporation of heavy metals; which are drawn off from the steelworks slag bath to leave a heavy-metal-depleted slag bath. The residual bath is reduced with carbon carriers to form a slag phase and a pig iron phase. The slag phase can be granulated to produce mixed cement components.

Abstract: Described herein is an Improved Converter System designed to help reduce air, land and water pollution by completely converting materials that presently cause pollution into clean burning fuels and a host of other products beneficial to mankind. The primary conversion unit in the system is a zone controlled multipurpose slagging-ash oxygen jet blast converter. All incoming materials are passed through this process computer aided talented offspring of its two ancient prototypes the blast furnace and slagging-ash gas producers and the zone controlled blast furnaces described in U.S. Pat. Nos. 4,381,938, 4,495,054, 3,928,023 and 3,814,404. It employs two sets of tuyeres located in the bosh to input endothermic reacting gases, vapors and dusts through tuyere sets T1 and T2. A 100% oxygen jet blast is also input through tuyere set T2.

Abstract: The residues arising from industrial processes and from waste disposal which are polluted with heavy metals and/or heavy metal compounds, are subjected to a two-stage reduction process with formation of re-usable metal-containing and silicon-containing alloys. In a first reduction stage, using carbon or carbon-generating means as the reduction means, the compounds of silicon and metals are reduced, which have a standard potential which is greater than that of silicon. Following separation of the reduced metals, the residue obtained, which contains aluminum in oxidized form, is subsequently converted to a salt melt and this salt melt is subjected to a second reduction stage of a fused salt electrolysis, yielding an aluminum and silicon melt. The process is particularly suitable for filter residues from waste incineration plants.

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: To produce pig iron or steel and cement clinker from slags it has been proposed to react iron-oxide containing liquid slags, such as, e.g., steelworks slag, with iron oxide carriers, such as, e.g., ores, cinders or the like and lime to a ferrite-containing slag and to reduce the formed ferrite slag in a reduction reactor, such as, e.g., an iron bath reactor, whereupon the sinter phase is discharged as a clinker.

Abstract: In a process for the production of hydraulic binders, crude steel and/or alloys, such as, e.g., FeCr or FeV, from basic steel slags containing chromium and/or vanadium, the liquid steel slag is mixed with an additive selected from the group consisting of blast furnace slag, electric arc furnace slag, dusts from steel production, metallic waste substances or refuse incineration residues and/or with acid additives for lowering the viscosity, whereupon steel is sedimented out of the liquid slag and the remaining slag in a first reduction stage is reduced to metallic iron having an iron oxide content of below 5 wt. % and above 1 wt. %, whereupon the remaining slag melt in a second reduction stage having a higher reduction potential as compared to the first reduction stage is further reduced to metallic Cr or V or ferroalloys thereof and the hydraulically active slag is separated.

Abstract: Method for neutralizing waste, such as powder from luminescent tubes and similarly, residue from incineration of household waste, optionally comprising environmentally hazardous components, such as Hg, Cd, Zn, Co or Ba. The waste is fed into a melting furnace in conjunction with an SiO.sub.

Abstract: A thermally stable steelmaking slag is produced which is suitable for use in applications requiring dimensional stability, e.g. as aggregate in road construction. Fine particles of slag obtained from a basic oxygen furnace operation or from an arc furnace operation is firstly subjected to a thermal hydration at a temperature in the range of about 100.degree. to 400.degree. C. Thereafter, the hydrated slag particles are carbonated in the presence of carbon dioxide at a temperature in the range of about 500.degree. to 900.degree. C., whereby substantially all free calcium oxide in the slag particles is converted to calcium carbonate. The product obtained is well suited for road construction and cementitious applications.

Abstract: In a process for the preparation of cement from metallurgical slags, in which liquid slags from reduction processes and steelworks processes, e.g. blast furnace and converter slag, are mixed together and mixed with lime the procedure is such that in a first cooling phase at temperatures above 1000.degree. C., and preferably above 1200.degree. C., the cooling is slower than in a subsequent second cooling phase and that the solidified product obtained is granulated and/or ground in order to obtain directly cement with improved hydraulic properties, in particular increased final strength.

Abstract: In a process for the preparation of pig iron and cement clinker in a fusion gasifier (3) in which the charge is at least partly preheated and possibly deacidified and subjected to preliminary reduction or is used in the form of scrap, coal is blown into a fluidized bed (7) and gasified with the reduction of the charge and pig iron (8) and slag (9) are tapped off in liquid form, the procedure is such that the lime charge introduced into the fusion gasifier (3), possibly together with a portion of an iron ore, is preheated in a preheating shaft (1) and calcined and charged according to the clinker composition required.

Abstract: In the processing of mainly inorganic refuse incineration products polluted by heavy metals and/or heavy metal compounds, and/or analogues of such products, to give environmentally acceptable products by melt-thermal treatment, an iron-containing melt is used whose iron content can be adjusted by addition of iron or an iron compound. The melt is first melted above 1300.degree. C. in a reactor. The melt is then oxidized with vigorous agitation by blowing in oxygen-containing gas until all the metals and metal compounds present in the reactor have been converted to the oxide form, the melt being kept above 1450.degree. C. and preferably at about 1500.degree. C., at least at the end of the oxidation. Subsequently, the melt is reduced, preferably by means of a part fraction of the refuse incineration product and/or iron, preferably in the form of scrap, and/or hydrogen. The reduction can then be continued by means of added aluminum and/or calcium and/or ferrosilicon.

Abstract: The invention relates to a method for preparing a hydraulically settable cement base material starting from steel slags formed in a steel-making process, which method comprises the formation, in steel slags in the liquid state, of a ferrite gradient by adding a ferrite-precipitating compound, the separation, if required, of the high-ferrite fraction formed, the separation of at least the low-ferrite fraction formed, the cooling and the comminution thereof to obtain a hydraulically settable material. The ferrite-precipitating compound used has preferably acid components, and can expediently generate silicic acid. At least before the cooling of the low-ferrite fraction, the aluminum content of the liquid slag material is regulated by the addition of an aluminate-containing material, such as bauxite. The high-ferrite fraction separated can be returned to the steel-making process to reduce or remove the addition of a flux in the production of steel.

Abstract: The specification discloses a process for heating solid particulate materials. The process comprises entraining the solid particulate materials in a gas to form a stream of gas containing entrained particles and containing this stream with a stream of hot gases. The contact between the two streams is performed in such a manner that at least a portion of the solid particulate material is heated rapidly and the heated and unheated particles enter flow patterns in which contact between the particles and with interior surfaces of contact chamber is minimized. A heating and treatment chamber for applying the process to the treatment of solid particulate materials is disclosed. The specification also discloses a molten bath reactor combined with the chamber for heating and treating solid particulate materials.

Abstract: The proposed method is characterized in that the liquid bath is constituted by the melt of low carbon steel and molten slag. Oxidation and reducing zones are created through which, along a closed path on the surface of the molten low-carbon steel, is circulated the molten slag, into which are blown powder slag materials which are melted with the heat of a fuel oxygen torch immersed into the melt. The melting is carried out in a melting reservoir shaped as a closed annular chamber (1) provided with partitions (11) hermetically dividing the gas space above the molten slag into oxidation (6) and reducing (7) zones.