SU440421A1 - Blend Mix - Google Patents

Description

The invention relates to ferrous metallurgy and can be used as a mixture for deoxidizing a liquid metal through slag.

The known mixture for the extraction of steel and alloys, containing,%: silicon carbide 8-40, aluminum oxide 0.5-10, magnesium oxide 0.5-5.0, calcium oxide 0.5-10.0, fluorspar 0, 5-5.0, the rest is metal powder (chips). The mixture is designed to deoxidize oxidative slags containing a significant amount of oxides doped: their elements, with simultaneous additional doping of the smelted metal with elements included in the metal component of the mixture.

However, the known mixture is not sufficiently effective for the deoxidation of highly basic slags of the recovery period, since it does not provide the necessary liquid mobility. In addition, the amount of deoxidizing agent (silicon carbide) in this mixture is not enough to introduce slag with a very low content of ferrous oxide, which provides a metal with a low content of sulfur and oxygen.

The proposed mixture provides an institution of highly mobile active refining slag with a low content of ferrous oxide in it, thereby reducing the content of sulfur and oxygen in the finished metal.

For this, cryolite is introduced into a mixture consisting of silicon carbide and alumina in the following ratio of components, wt.%: Silicon carbide 50-75, alumina 23-

40, cryolite - the rest.

The content of cryolite depends on the amount of alumina used in the mixture: the more alumina in the mixture, the more it is necessary to introduce cryolite.

The proposed mixture was tested in the smelting of high-speed steel RBL15 in a commercial and titonic electric arc furnace. A mixture containing 65% silicon carbide, 30% alumina and 5% cryolite was used. The mixture was fed to the highly basic shlak of the reduction period in an amount of 55 kg per smelting during the whole refining period. At the same time, the slag had high activity, which provided final iron oxide content of 0.47%, and oxygen content in the finished metal was 0.0048% and sulfur content was 0.008%.

Subject invention

A oxidative blend containing silicon carbide and alumina, characterized in that, in order to reduce the sulfur and oxygen content in the metal, cryolite is introduced into it at the following ratio of components, wt.%: Silicon carbide 50-75, alumina 23-40, cryolite - the rest.