Patent ID: 8764879
Filing Date: 2014-07-01
Classification: C21C,Y02P

Abstract:
1. A method of slag foaming of a molten slag present on a steel melt during manufacture of non-stainless steel in an electric arc furnace, the method comprising adding pellets or briquettes to the slag, whose contents react in a reducing manner with Fe-oxides while splitting off gas, wherein reaction gases produced lead to slag foaming, the pellets or briquettes charged into the electric arc furnace are of a defined mixture of an iron oxide carrier, limestone, ballast material, and a carbon carrier as reduction agent, as well as a binder, wherein the pellets or briquettes are manufactured with respect to density so that the pellets or briquettes float in the steel melt directly underneath a phase border melt/slag, and react in a reducing manner underneath the slag layer with the iron oxide and carbon contained in the pellets or briquettes, and wherein a dissolution duration of the pellets or briquettes resulting from their size and density causes a reduction of the iron oxide, wherein the pellets or briquettes have a composition that varies within the following ranges: the method including adjusting the density of the pellets or briquettes to values of between 3 to 4 tons/m 3 , and average dimensions of the pellets or briquettes to values between a height of 10 to 50 mm, a length of 10 to 60 mm and a width of 10 to 50 mm.