The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 25, 2011
Filed:
Jan. 10, 2008
Johann Reichel, Düsseldorf, DE;
Lutz Rose, Duisburg, DE;
Johann Reichel, Düsseldorf, DE;
Lutz Rose, Duisburg, DE;
SMS Siemag Aktiengesellschaft, Dusseldorf, DE;
Abstract
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 (), which are made of a defined mixture of an iron carrier as the ballast material, carbon, or carbon and silicon, as the reducing agent, and a binder, wherein they react beneath the slag layer () in the steel melt () with the metal oxides of the slag (), particularly with the chromium oxide present, in a floating, chemical, and reducing manner. The reaction gases () produced in the process, which are mainly made of carbon monoxide, advantageously support a foaming of the slag ().