Sms Schloemann-siemag Aktiengesellschaft

Sms Demag Ag

Wei-Ping Wu

Fritz-Peter Pleschiutschnigg

Karl-Josef Schneider

Karl-Heinz Deppner

An apparatus for producing steels with predominantly high Cr content and/or ferro-alloys, wherein the metal charge is melted in a melting crucible, is alloyed, refined and reduced, and wherein process gases are simultaneously supplied through bottom nozzles. A melting crucible is used with a specific reaction volume of 0.4 to 1.5 m /t steel and the injection rates of the process gases are controlled in the range of 0.1 to 3.0 N m /t/min. The solid charge material is melted by an electric arc and air/nitrogen are injected simultaneously and, after forming a liquid sump, a gas mixture of oxygen and inert gas is injected. After adding slag-forming constituents and alloying agents, the oxygen throughput is increased and the power of the electric arc is reduced accordingly. The oxygen throughput is reduced in relation to the inert gas during refining and decarburization takes place as a result of increasing the electric arc with low chromium slag formation. During the reduction of the melt with suitable reduction agents, primarily chromium is reduced from the slag and silicon is bound by slag-forming constituents.

Method and apparatus for producing high chromium content steels and/or ferroalloys in an electric arc converter

A direct-current arc furnace for producing steel has a smelting vessel with electrodes, tapping openings for the molten mass and slag, and a device for a direct removal of exhaust gases. The smelting vessel is extended upwardly by a central shaft for introducing melt-down material into the vessel. The extension of the central shaft forms a melt-down material column. A shaft suction device is provided as an extension of the shaft for removal of the exhaust gases during the smelting process. Adjacent to the shaft openings are provided in the upper part of the smelting vessel for receiving a vessel suction device for dust and/or gases resulting during the charging process of the melt-down material. The shaft suction device and the vessel suction device are connected to a common device and switching elements are provided for actuating only one suction device and/or adjusting a combination of the exhaust gas flows dependent on the charging and smelting process.

Direct-current arc furnace comprising a centric charging shaft for producing steel and a method therefor

In a method for sealing a tap opening in a metallurgical container a plug with a plug sleeve and a refractory flowable material is provided having a metal rod or pipe surrounded by a protective pipe connected thereto. The plug sleeve and the protective pipe are made of a material resistant to a molten mass of metal in the metallurgical container only for a short period of time. The material is a temporarily heat-insulating material which cokes within the molten mass of metal and is cardboard or wood. The time of introduction of the plug sleeve is controlled based on measured parameters of the molten mass. The plug is introduced into the tap opening by guiding the plug with the metal rod or pipe through the molten mass in the metallurgical container. The plug sleeve changes by temperature action of the molten mass of metal such that the flowable material is distributed in the tap opening and seals the tap opening. The tap opening is then closed from the exterior of the metallurgical container and the plug sleeve in the tap opening as well as the protective pipe are coked and destroyed.

Method and device for sealing a tap hole in metallurgical containers

A method of and an apparatus for the production of steel utilizing a single vessel for the electric arc smelting of scrap, directly reduced iron or pig iron in solid form, and for the oxygen blowing of the resulting melt through an oxygen lance introduced via a tower-shaped part of the roof. Another part of the roof can pivot to allow charging of the furnace with solids and the tower can be provided with a funnel enabling a molten iron charge to be fed to the furnace.

Apparatus for producing steel utilizing an electrical steel making

A method and an apparatus for producing steels with predominantly high Cr content and/or ferro-alloys, wherein the metal charge is melted in a melting crucible, is alloyed, refined and reduced, and wherein process gases are simultaneously supplied through bottom nozzles. A melting crucible is used with a specific reaction volume of 0.4 to 1.5 m.sup.3 /t steel and the injection rates of the process gases are controlled in the range of 0.1 to 3.0 N m.sup.3 /t/min. The solid charge material is melted by an electric arc and air/nitrogen are injected simultaneously and, after forming a liquid sump, a gas mixture of oxygen and inert gas is injected. After adding slag-forming constituents and alloying agents, the oxygen throughput is increased and the power of the electric arc is reduced accordingly. The oxygen throughput is reduced in relation to the inert gas during refining and decarburization takes place as a result of increasing the electric arc with low chromium slag formation. During the reduction of the melt with suitable reduction agents, primarily chromium is reduced from the slag and silicon is bound by slag-forming constituents.

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Erkrath, Germany

Wei-Ping Wu