Patent application number | Description | Published |
20100288078 | PROCESS FOR PRODUCING STAINLESS STEEL USING DIRECT REDUCTION FURNACES FOR FERROCHROME AND FERRONICKEL ON THE PRIMARY SIDE OF A CONVERTER - In order to allow a significant reduction of the steel production costs when producing stainless steel with the alloying elements chromium and nickel, according to the invention, it is proposed to perform the intermediate production of ferrochromium and ferronickel in two separate direct reduction processes based on low-cost chromium ore and nickel ore in two SAF ( | 11-18-2010 |
20110088514 | Process for Producing a Foamed Slag on Austenitic Stainless Melts in an Electric Arc Furnace - 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. | 04-21-2011 |
20110146447 | Method for Controlling Foamed Slag in a Stainless Melt in an Electronic Arc Furnace - 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. | 06-23-2011 |
20110197708 | Process for Producing Foamed Slag - 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. | 08-18-2011 |
20130192422 | BRIQUETTE FOR PRODUCING A FOAMED SLAG EFFECT IN EAF TECHNOLOGY IN STAINLESS STEEL PRODUCTION - 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. To provide, according to the invention, briquettes suitable for producing foamed slag having a high chromium oxide content, which is carried out, in particular by the process of WO 2010/003401 A1, all briquette properties to be taken into account and all materials suitable for briquette production are tabulated in the form of a matrix. | 08-01-2013 |
20140352496 | BRIQUETTE FOR PRODUCING A FOAMED SLAG EFFECT IN EAF TECHNOLOGY IN STAINLESS STEEL PRODUCTION - 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:
| 12-04-2014 |
Patent application number | Description | Published |
20090031860 | Production of Stainless Steel of AISI 4XX Grade Ferritic Steel in an Aod Converter - For the production of stainless steel of the ferritic AISI 4xx group of steels, particularly the AISI 430 group of steels, based on liquid pig iron and FeCr solids, the invention proposes the use of the AOD (Argon Oxygen Decarburization) process in which oxygen and inert gas (inactive gas) together are blown into the bath through nozzles and top-blown onto the surface of the bath by a blowing lance. The aim of the treatment is to conclude a smelting charge within an optimal time period, to achieve the intended tapping temperature and composition, and to minimize chromium losses. This is achieved by a correspondingly applied technology and by means of a metallurgic process model which observes, prognosticates and controls the treatment of the smelting charge. | 02-05-2009 |
20090255375 | Method for the Production of a Foamed Slag in a Metal Bath - The invention relates to a method for producing a foamed slag ( | 10-15-2009 |
20100011909 | METHOD AND DEVICE FOR PRODUCING PIG-IRON BASED STAINLESS STEEL WITHOUT USING A SUPPLY OF ELECTRICAL ENERGY - 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 ( | 01-21-2010 |
20100024600 | METHOD AND DEVICE FOR PRODUCING STAINLESS STEEL WITHOUT USING A SUPPLY OF ELECTRICAL ENERGY, BASED ON PIG-IRON THAT HAS BEEN PRE-TREATED IN A DDD INSTALLATION - 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 ( | 02-04-2010 |
20100089202 | METHOD FOR THE REDUCTION OF A SLAG HAVING A HIGH DEGREE OF CHROMIUM IN AN ELECTRIC ARC FURNACE - During the production of stainless steel, a slag is formed during the melting of the solid material in the electric arc furnace, the slag having a high degree of metal oxides, particularly chromium oxide. The chromium concentration often reaches values of more than 30%. Currently, such slags cannot be reduced to a desired degree due to their composition. In order to minimize the resulting high loss of recyclable material, the invention provides to charge the electric arc furnace with pellets, or briquettes ( | 04-15-2010 |
20100192672 | Indirect Determination of the Waste Gas Rate for Metallurgical Process - 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. | 08-05-2010 |
20110227263 | METHOD AND DEVICE FOR PRODUCING STAINLESS STEEL WITHOUT USING A SUPPLY OF ELECTRICAL ENERGY, BASED ON PIG-IRON THAT HAS BEEN PRE-TREATED IN A DDD INSTALLATION - 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 and a DDD device is separated and introduced into two classic “twin” AOD-L converters, where the required chemical process steps (of the heating, decarburisation 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 and the decarburisation being carried out first in the second twin AOD-L converter. | 09-22-2011 |
20120175828 | METHOD AND DEVICE FOR PRODUCING PIG-IRON BASED STAINLESS STEEL WITHOUT USING A SUPPLY OF ELECTRICAL ENERGY - 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. | 07-12-2012 |
20130000446 | METHOD FOR PRODUCING FOAMED SLAG ON HIGH-CHROMIUM MELTS IN AN ELECTRIC FURNACE - 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. | 01-03-2013 |
20130018508 | CONTROL OF THE CONVERTER PROCESS BY MEANS OF EXHAUST GAS SIGNALSAANM Reichel; JohannAACI DusseldorfAACO DEAAGP Reichel; Johann Dusseldorf DE - 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. In order to allow control of the converter process for producing steel independently of the predefined process model, in particular when blowing oxygen, the invention proposes that detected values for the critical decoking point (t′ | 01-17-2013 |
20130019714 | METHOD FOR FOAMED SLAG GENERATION OF A NON-CORROSIVE MELT IN A CONVERTER - 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 ( | 01-24-2013 |