Abstract: Briquette for producing a foamed slag on stainless steel melts in an electric arc furnace, made up of mixtures of individual or multiple substances of following basic components: O2 carrier Dust, sludge or slag with ?10% FeO/Fe2O3, Dust, sludge or slag with ?1% Cr2O3, Dust, sludge or slag with ?1% MnO, Dust, sludge or slag with ?1% NiO, Scale with ?10% FeO/Fe2O3, Gas carrier Dust with ?40% CaCO3, Density adjuster Dust with FeCr, Dust with Fe/low alloy fine scrap, Dust with Cr/ferritic fine scrap, Dust with Ni/austenitic fine scrap, grinding dust, Dust with Mn/ferritic or low alloy fine scrap, Reducing agent Carbon-containing substances ?90% C, Dust or fine granulate of coke, coal or graphite, Binder Molasses, cement, Ca(OH)2, in each case ?5% by weight.

Abstract: An installation for producing stainless steel for all stainless steel products both in the austenitic and the ferritic range, based on liquid pig-iron and FeCr solids, without using a supply of electrical energy. The liquid pig-iron, after being pre-treated in a blast furnace, is subjected to a DDD treatment (dephosphorisation, desiliconisation and desulphuration), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace is separated and introduced into two classic “twin” AOD-L converters, where the required chemical process steps (of the DDD treatment and of the heating, decarburization and alloying stages) take place in parallel contrary processes using autogenous chemical energy, the DDD treatment being carried out first in the first twin AOD-L converter and the decarburization being carried out first in the second twin AOD-L converter.

Abstract: During the production of non-stainless steel, slag containing a high proportion of metal oxides, primarily iron oxide, is formed during the smelting of the solid material in the electric arc furnace. The concentration of the iron oxide often reaches values of more than 20%. This slag has a poor foaming capability and does not permit the typical characteristics of a carbon steel slag to be achieved. In order to cause such a slag to foam, according to the invention it is proposed to load the electric arc furnace with pellets or briquettes (8) which consist of a defined mixture of an iron oxide carrier and an iron carrier as ballast material, of carbon as reducing agent and also of a binder material, which react in the electric arc furnace in a reducing manner, floating under the slag (7) in the steel melt (6). The reaction gases (12) produced in this way consist primarily of carbon monoxide and advantageously support the foaming of the slag.

Abstract: In order to carry out foaming of a slag having a high ratio of chromium oxide having values of often above 20% of a non-corrosive melt in an AOD (Argon Oxygen Decarburization) or MRP (Metallurgical Refining Process) converter or CONARC SSt for stainless steel by adding a foam material, according to the invention a previously defined mixture (5) of a metal oxide, iron carrier, carbon and binding material in the form of pellets or briquettes (4) is introduced into the converter, which reacts in a chemically reducing manner under the slag layer (2) due to the high ambient temperature, wherein gaseous carbon monoxide formed in particular by means of the reduction process of the metal oxide with the carbon within the pellets or briquettes (4) induces the slag foaming with the gas bubbles (7) thereof and wherein the specific density of the pellets or briquettes (4) and the resolve time of the reduction process are selected so that optimal bubble formation in respect of size and duration is achieved.

Abstract: A method for controlling foamed slag in a stainless melt in an electric arc furnace. Slag level in the electric arc furnace is continuously detected thermographically as a function of time and slag level, and an addition of foaming material is controlled depending on the temperature and temperature gradient.

Abstract: A process and material for producing foamed slag by which the foaming of a slag with a high chromium oxide content can be achieved. An electric arc furnace is charged with a mixture of metal oxides and carbon and, below the slag at the metal-slag interface, the metal oxide is reduced by carbon and limestone and becomes thermally discordant. The occurring gases cause the slag to foam due to the formation of bubbles.

Abstract: It is known that a foamed slag can be produced on stainless steel melts in an electric arc furnace by introducing a mixture of metal oxides, limestone, carbon and a binder in the form of briquettes into the furnace so that the briquettes become arranged there in such a way that the metal oxides are reduced by the carbon and the limestone is thermally dissociated at the metal-slag interface beneath the slag and the resulting gases bring about foaming of the slag by bubble formation. This foaming on steels having a high chromium content, due to the significant uptake of chromium oxide by the slag, leads to problems which result from the physicochemical properties of slags having a high chromium oxide content.

Abstract: Modern steel production processes require precise knowledge of the current composition and temperature of the liquid metal being processed. In particular during steel production in a converter, high match rates for final carbon content and bath temperature are required. Quantitatively precise blowing of oxygen corresponding to the final target carbon content, and the metal temperature, are decisive factors affecting the economic efficiency of the process and the quality of the steel produced. In order to allow relatively precise process monitoring, various processes and procedures are known, the application thereof being based on measuring exhaust gas composition and on mass flow balances. All models work at an exactness that depends on the precision of the input data, particularly with respect to the weight data of the raw materials and the chemical properties of the metal used.

Abstract: The aim of the invention is to produce stainless steel for all stainless steel products both in the austenitic and the ferritic range, based on liquid pig-iron and FeCr solids, without using a supply of electrical energy. According to the invention, the liquid pig-iron, after being pre-treated in a blast furnace (1), is subjected to a DDD treatment (dephosphorization, desiliconization and desulfuration), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace (1) is separated and introduced into two classic “twin” AOD-L converters (2, 3), where the required chemical process steps (of the DDD treatment and of the heating, decarburization and alloying stages) take place in parallel contrary processes using autogenous chemical energy, the DDD treatment being carried out first in the first twin AOD-L converter (2) and the decarburization being carried out first in the second twin AOD-L converter (3).

Abstract: An installation for producing stainless steel for all stainless steel products both in the austenitic and the ferritic range, based on liquid pig-iron and FeCr solids, without using a supply of electrical energy. The liquid pig-iron, after being pre-treated in a blast furnace, is subjected to a DDD treatment (dephosphorization, desiliconization and desulphurization), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace and a DDD device is separated and introduced into two classic “twin” AOD-L converters, where the required chemical process steps (of the heating, decarburization and alloying stages) take place in parallel contrary processes using autogenous chemical energy. The heating stage is carried out first in the first twin AOD-L converter and the decarburization is carried out first in the second twin AOD-L converter.

Abstract: A process for producing a foamed slag on austenitic stainless melts in an electric arc furnace. A mixture of metal oxides and carbon is introduced into the furnace, the metal oxide is reduced by the carbon below the slag at the metal/slag interface, and the resulting gases bring about the foaming of the slag by bubble formation. The mixture to be charged, which is added in the form of preforms such as briquets or pellets, contains iron oxide, iron carriers, carbon and the required binders in addition to nickel oxide.

Abstract: In order to carry out foaming of a slag having a high ratio of chromium oxide having values of often above 20% of a non-corrosive melt in an AOD (Argon Oxygen Decarburization) or MRP (Metallurgical Refining Process) converter or CONARC SSt for stainless steel by adding a foam material, according to the invention a previously defined mixture (5) of a metal oxide, iron carrier, carbon and binding material in the form of pellets or briquettes (4) is introduced into the converter, which reacts in a chemically reducing manner under the slag layer (2) due to the high ambient temperature, wherein gaseous carbon monoxide formed in particular by means of the reduction process of the metal oxide with the carbon within the pellets or briquettes (4) induces the slag foaming with the gas bubbles (7) thereof and wherein the specific density of the pellets or briquettes (4) and the resolve time of the reduction process are selected so that optimal bubble formation in respect of size and duration is achieved.

Abstract: Modern steel production processes require precise knowledge of the current composition and temperature of the liquid metal being processed. In particular during steel production in a converter, high match rates for final carbon content and bath temperature are required. Quantitatively precise blowing of oxygen corresponding to the final target carbon content, and the metal temperature, are decisive factors affecting the economic efficiency of the process and the quality of the steel produced. In order to allow relatively precise process monitoring, various processes and procedures are known, the application thereof being based on measuring exhaust gas composition and on mass flow balances. All models work at an exactness that depends on the precision of the input data, particularly with respect to the weight data of the raw materials and the chemical properties of the metal used.

Abstract: A method for the indirect determination of the waste gas rate in metallurgical processes. A reference gas such as helium is first added to the waste gas, specifically at a time which, with respect to flow, sufficiently precedes the taking of a sample such that a thorough mixing of the reference gas and waste gas is carried out, i.e., a virtually homogeneous distribution is achieved, and a quantitative helium analysis and nitrogen analysis of the waste gas, measured by a mass spectrometer, is carried out while taking into account the added amount of helium.

Abstract: The invention relates to a method for producing foamed slag on high-chromium steel melts in an electric furnace, whereby a mixture consisting of a metal oxide and carbon is introduced into the furnace, the metal oxide in the slag is reduced by the carbon, and the gases created in the slag form bubbles which thus foam up the slag. In order to be able to control the gas formation and thus the foaming process, the mixture consisting of a metal oxide and carbon and optionally an iron carrier is introduced as preforms, such as pellets, which are compressed and/or provided with a binding agent. The gas formation can be controlled in terms of location, type and time, by adjusting the characteristics of the pellets, especially the density and/or compression characteristics thereof.

Abstract: The aim of the invention is to produce stainless steel for all stainless steel products both in the austenitic and the ferritic range, based on liquid pig-iron and FeCr solids, without using a supply of electrical energy. According to the invention, the liquid pig-iron, after being pre-treated in a blast furnace, is subjected to a DDD treatment (dephosphorisation, desiliconisation and desulphuration), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace is separated and introduced into two classic “twin” AOD-L converters, where the required chemical process steps (of the DDD treatment and of the heating, decarburization and alloying stages) take place in parallel contrary processes using autogenous chemical energy, the DDD treatment being carried out first in the first twin AOD-L converter and the decarburization being carried out first in the second twin AOD-L converter.

Abstract: In order to allow a significant reduction of the steel production cost when producing stainless steel with the alloying elements chromium and nickel, according to the invention, it is proposed to perform the intermediate production of ferrochrimium and ferronickel in two separate direct reduction processes based on low-cost chromium ore and nickel ore in two SAF (3, 4) arranged in parallel on the primary side of a processing converter (6).

Abstract: During the production of non-stainless steel, slag containing a high proportion of metal oxides, primarily iron oxide, is formed during the smelting of the solid material in the electric arc furnace. The concentration of the iron oxide often reaches values of more than 20%. This slag has a poor foaming capability and does not permit the typical characteristics of a carbon steel slag to be achieved. In order to cause such a slag to foam, according to the invention it is proposed to load the electric arc furnace with pellets or briquettes (8) which consist of a defined mixture of an iron oxide carrier and an iron carrier as ballast material, of carbon as reducing agent and also of a binder material, which react in the electric arc furnace in a reducing manner, floating under the slag (7) in the steel melt (6). The reaction gases (12) produced in this way consist primarily of carbon monoxide and advantageously support the foaming of the slag.

Abstract: The aim of the invention is to produce stainless steel for all stainless steel products both in the austenitic and the ferritic range, based on liquid pig-iron and FeCr solids, without using a supply of electrical energy. According to the invention, the liquid pig-iron, after being pre-treated in a blast furnace (1), is subjected to a DDD treatment (dephosphorization, desiliconization and desulphuration), is heated, finished or alloyed and deoxidated. The quantity of slag-free liquid pig-iron that has been pre-treated in the blast furnace (1) and a DDD device (2) is separated and introduced into two classic “twin” AOD-L converters (3, 4), where the required chemical process steps (of the heating, decarburization and alloying stages) take place in parallel contrary processes using autogenous chemical energy, the heating stage being carried out first in the first twin AOD-L converter (3) and the decarburization being carried out first in the second twin AOD-L converter (4).

Abstract: A method for producing a foamed slag (1) on a metal bath (2) in a metallurgical furnace (3), in which a mixture (4) containing at least one metal oxide and carbon is introduced into the furnace (3), the metal oxide is reduced by the carbon below the slag (1) that is located there, and the gases produced during the reduction process form bubbles such that the slag is foamed. In order to optimize the formation of foamed slag, the mixture (4) is delivered into the furnace (3) in such a way that a desired height (h) or a desired section of the height (h) of the layer of foamed slag (1) is generated or maintained.