Stahlwerke Peine-salzgitter Ag

Gustav Mahn

Paul Rheinlander

Klaus Berner

Klaus Schulz, Deceased

Karl Brotzmann

Helmut Knuppel

Josef Schoop

By Ingrid Ruhland, Legal Representative

Jorg Kugler

Dieter Nolle

Ulrich Eulenburg

Ingrid Ruhland, Legal Representative

A method is provided for production of steel in a basic converter employing liquid converter slag obtained as a final slag in the previous run, where roughly half of the slag from the preceding charge is left in the converter. The basicity of the initial slag is thus considerably increased and the slag is maintained preferably over the total converting process, but at least during the critical initial stage at the saturation level with respect to magnesium oxide and dicalcium orthosilicate. At a certain level of silicon content in the pig iron the process is operated with a predetermined slag amount for each ton of steel at the end of the blowing by adding to the initial melt or respectively at the beginning of blowing a certain amount of magnesium oxide expending on the silicon content of the pig iron together with the flux charge materials. This process considerably improves the lifetime of the converter lining. In addition the amount in flux materials is considerably decreased and the slag composition is made more uniform over the run. Furthermore, the metallurgical quality of the product is improved.

Production of steel in a basic converter employing liquid converter slag

The continuous refining of molten metal is carried out in a refining apparatus having communicating first and second refining stage spaces. Refining gas, such as oxygen, is blown into the molten metal in the presence of a slag layer on the molten metal. The molten metal and the slag are conveyed as two separate non-intermingled streams through the refining stage spaces, as distinguished from a slag-metal emulsion. The slag in the second refining stage space is caused continuously to flow back into the first refining stage space to form a slag layer on the molten metal in the first refining stage space. Refining gas is blown into the molten metal in the first refining stage space below the slag layer, and the molten metal is conveyed from the first refining stage space to the second refining stage space while preventing the flow of slag from the first refining stage space to the second refining stage space. Refining gas is blown onto the molten metal in the second refining stage space in the presence of slag so that a slag layer on the molten metal in the second refining stage space is formed. The molten metal and the slag are separated from each other after the molten metal has passed through the second refining stage space.

Apparatus for continuously refining molten metals

A process for continuous refining in which liquid pig iron is supplied to a pig iron melt which is at least partially refined while said melt is being intensively agitated, the refining means (preferably oxygen) is introduced into the pig iron melt by means of tuyeres mounted in the refining vessel, and discharging the refining means beneath the surface of thepig iron melt, the tuyeres being positioned and the refining means being furnished so that the kinetic energy of the refining means contributes to the bath agitation. The tuyeres are preferably composite tuyeres like those described in U.S. Pat. Nos. 3,706,549 issued Dec. 19, 1972 and 3,771,998 issued Nov. 13, 1973, for discharging oxygen surrounded by a gaseous and/or liquid hydrocarbon, and possibly lime or other solid powder into the bath.

Process for making steel from pig iron

Oxygen or oxygen-containing gas is blown onto a molten crude iron bath inside a converter. A layer of slag or metal-slag emulsion forms atop the molten crude iron bath and grows in height during the course of the refining reaction. The height of such layer is indirectly determined by detecting an electrical characteristic of the layer. The layer of slag or metal-slag emulsion is made to serve as the dielectric of a capacitive reactive and/or as the flux-permeable part of an inductive reactance, and such reactance, or a plurality of such reactances, form part of a resonant circuit.

Method for monitoring and controlling the refining of crude iron

The disclosed process of continuously refining molten metal is carried out in a refining apparatus having communicating first and second refining stage spaces. Refining gas, such as oxygen, is blown into the molten metal in the presence of a slag layer on the molten metal. The molten metal and the slag are conveyed as two separate non-intermingled streams through the refining stage spaces, as distinguished from a slag-metal emulsion. The slag in the second refining stage space is caused continuously to flow back into the first refining stage space to form a slag layer on the molten metal in the first refining stage space. Refining gas is blown into the molten metal in the first refining stage space below said slag layer, and the molten metal is conveyed from said first refining stage space to said second refining stage space while preventing the flow of slag from said first refining stage space to said second refining stage space. Refining gas is blown onto said molten metal in said second refining stage space in the presence of slag so that a slag layer on the molten metal in said second refining stage space is formed. The molten metal and the slag are separated from each other after the molten metal has passed through said second refining stage space.

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Wolfenbuttel, Germany

Gustav Mahn