Scandinavian Lancers Aktiebolag

Scandinavian Lancers Aktiebolaget

Bertil G Tivelius

Apparatus for treating molten metal comprising a ladle for containing a molten metal to be treated having an upper edge, a hood arranged above the ladle and comprising a heat shield essentially covering completely the ladle and having a ceramic lining facing the molten metal in the ladle, with the heat shield and the upper edge of the ladle being spaced from each to define a gap between the heat shield and the upper edge of the ladle. A screen forms and all-enveloping roof over the heat shield and extends over and below the gap to define a circumferential opening between the screen and the ladle below the gap, and spacing means extending between the screen and the heat shield are provided for maintaining the screen and the heat shield spaced apart with respect to each other to define a chamber between the screen and heat shield. The gap communicates with the chamber for the passage of gases therethrough from the ladle to the chamber, and the circumferential opening defines an inlet opening for ambient air to the chamber. At least one lance means is provided for introducing at least one gas in the molten metal in the ladle and/or to a ladle area above the molten metal, and at least one exhaust means communicating with the chamber is provided for exhausting gases which pass from the ladle area above the molten metal into the chamber through the gap, and also for exhausting air which is sucked from the ambient atmosphere into the chamber mainly through the circumferential opening. At least one aperture means is provided in the hood for lowering at least one of the lance means into the ladle.

Apparatus for refining of steel melts

A method for refining of steel melts for production of steel, especially stainless steel, with extremely low oxygen content is characterized in that a powdered non-oxidic earth alkali metal compound or alloy is injected by means of a non-oxidizing carrier gas, preferably an inert gas, into a well de-oxidized steel melt which is covered by a basic reduced slag in a metallurgical ladle, whereby at least a significant amount of the earth alkali metal is oxidized by the oxygen dissolved in the melt to form small particles of earth alkali metal oxide, of which some are separated out to the slag cover while the remaining portion of the earth alkali metals stays behind in the melt in elementary form or combined in the form of particulate earth alkali metal oxide in colloidal solution, and that then powdered earth alkali metal oxide is injected, whereby there latter, larger oxide particles function as nucleus forming agents for the continued reaction between earth alkali metals dissolved in the melt and oxygen, and also for separation to the slag cover of smaller inclusions already existing in the melt. There is also provided an equipment for carrying out the method comprising a hood arranged above the ladel and designed so as to prevent air from entering into the space between the hood and the surface of the steel melt.

Method for refining of steel melts

The invention relates to a method and equipment of producing with good reproducibility steel which is extremely free from slag inclusions, particularly steel with low sulphur content and thus very low contents of sulphidic slag inclusions, starting with a steel melt which is decarburized in a melting furnace, converter or the like to the desired carbon content, after which subsequent refining is carried out by an injection method in a ladle.

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Viken, Sweden

Bertil G Tivelius