Institut De Recherches De La Siderurgie Francaise (irsid)

Institut De Recherches De La Siderurgie Francaise

Institute De Recherches De La Siderurgie Francaise

Pierre Vayssiere

Jean-Claude Grosjean

Guy Denier

Jean-Pierre Motte

Aristide Berthet

J Colling

Roland Grave

F Schleimer

F Goedert

Charles Roederer

Georges Giroud

L Lorang

Bernard Bahout

R Henrion

A process for periodically and pneumatically stirring a bath of molten metal, wherein during the periods in which no stirring effect is required a fluid in gaseous state is injected through injection devices below the surface of the bath of molten metal in an amount sufficient to prevent blockage of the devices, whereas during the periods in which a stirring effect is required a fluid in liquid state which will vaporize quickly upon contact with the liquid metal is injected to provide an optimum amount of mixing gas with a minimum of injection devices. The process is advantageously used in converters for pneumatically converting pig iron into steel and in which oxygen is blown from above onto the bath of molten metal.

Process for periodically and pneumatically stirring a bath of molten

The refractory piece permeable to gases according to the invention is designed to be incorporated in the inner refractory lining of a metallurgical container so that one of its surfaces will be in contact with the molten metal bath in said container, the opposite surface being equipped with means for introducing a gas under pressure. This piece, whose shape is generally hexahedral, consists essentially of a mass of nonporous refractory material that has a number of local discontinuities 8 extending throughout the piece along its height h between the surface in contact with the molten metal and the opposite surface. In an advantageous method of embodiment, the local discontinuities 8 are obtained by an assembly 1, in a metal casing, of nonporous refractory elements 2, in the form of plates and which are placed side by side along their large lateral surfaces, without any material gaskets or seals between them. The piece according to the invention is easy to make. In addition, it has all of the required qualities of selectivity or orientation so that its life will be about as long as the life of the surrounding refractory lining of the metallurgical container in which it is designed to go, while allowing the desired amounts of gas to be blown into the metal bath.

Refractory piece permeable to gases

Stainless steel is produced in a converter with a tuyere defining a central conduit and a peripheral conduit concentrically surrounding the central conduit, by blowing an oxidizing refining gas through the central conduit into a molten metal bath, the refining gas initially consisting of pure oxygen and being subsequently diluted by gaseous argon, and injecting liquid argon into the converter through the peripheral conduit, to refine the molten metal bath until it has attained a desired level of carbon.

Process for producing stainless steel

In the production of steel from pig iron melted and refined in a vessel, the pig iron is preheated in two phases. In the first preheating phase, the cold pig iron and hot gases recovered from the melting and refining vessel are moved simultaneously through a first and higher rotary tubular furnace whose lower open end is in communication with an upper open end of a second and lower rotary tubular furnace constituting a second preheating phase. The second furnace is heated from the outside to regulate the temperature of the pig iron to a desired value before it is introduced into the vessel from the second furnace.

Process and apparatus for the production of steel

A wall element for furnaces useful in all types of metallurgical furnaces but particularly in electric arc steel refining furnaces is comprised of a metallic block defining a cooling circuit in the interior thereof and a lining of refractory bricks anchored firmly to the cooled metallic block. The metallic block carries anchoring lugs projecting from the internal face of the block, each lug consisting of a foot portion and a retaining portion, which is constituted by an enlarged end of the foot portion opposite the internal face. Each refractory brick has a face adjacent the internal face of the metallic block and defining a recessed portion of a cross section matching that of a corresponding one of the anchoring lugs.

Furnace wall element

Growing community of inventors

Metz, France

Pierre Vayssiere