Patent ID: 8409320
Filing Date: 2013-04-02
Classification: C21C,Y02P

Abstract:
1. A process for producing a foamed slag having a chromium oxide concentration of at least 10% on austenitic stainless melts in an electric arc furnace, comprising: selecting a preform comprising at least one of briquets and pellets, the preform having a specific density and dissolving time selected for optimal bubble formation with respect to magnitude and duration such that the selected preform floats below a slag/metal interface with a controlled bubbling with respect to the bubble magnitude and the bubble duration, the preforms comprising iron oxide, iron carriers, carbon, nickel oxide, and required binders; adding the preforms to a mixture to be charged so that the preforms are distributed two-dimensionally below the slag/metal interface; introducing the mixture of metal oxides and carbon is into the electric arc furnace; reducing the metal oxide by the carbon below a slag at a metal/slag interface; and foaming of the slag by bubble formation by resulting gases from the reducing of the metal oxide.