Abstract: A method for operating an electric arc furnace having at least one electrode, the method including the following steps: introducing material that is to be melted in the form of an actual mass flow into the electric arc furnace and feeding electrical energy via at least one electrode into the electric arc furnace in order to melt the introduced material depending on a previously determined, necessary electrical energy input. The necessary electrical energy input into the arc furnace is determined depending on the mass flow input into the furnace.

Abstract: A burner comprises a primary nozzle for injecting an oxygen-rich gas. The primary nozzle is designed as a supersonic nozzle. A coaxial nozzle having an annular outlet opening is provided for injecting a fuel gas. The coaxial nozzle is designed as a subsonic nozzle and is coaxial to the primary nozzle. The primary nozzle has a convergent portion and a divergent portion, which adjoin each other at a radius of the narrowest cross-section. The annular outlet opening is located at an end face of the burner. The fuel gas, in the form of hydrogen or a mixture of hydrogen and a hydrocarbon-containing gas, is injected at a fixed inlet pressure and a fixed inlet volumetric flow rate, with respect to a planned thermal power of the burner. In contrast, the inlet pressure and the inlet volumetric flow rate of the oxygen-rich gas are varied according to the application.

Abstract: A method for producing liquid pig iron comprises: i) providing a DRI product with an iron content of at least 75.0 wt. %, a carbon content of at least 0.10 wt. % and a content of acidic and basic slag components, comprising CaO, SiO2, MgO and Al2O3 of max. 15.0 wt. %; ii) supplying the DRI product, adding slag formers, into an electrically operated smelting unit; iii) optionally supplying further iron and/or carbon components into the electrically operated smelting unit; iv) smelting the DRI product and optionally the further iron and/or carbon components in the presence of the slag formers, so that a liquid pig iron phase and a liquid slag phase are formed; v) adjusting the slag phase such that it has a basicity of (CaO+MgO/SiO2) from 0.95 to 1.5; vi) tapping the liquid pig iron phase; and vii) tapping and granulating the slag phase.

Abstract: A method for operating an electric arc furnace having at least one electrode, the method including the following steps: introducing material that is to be melted in the form of an actual mass flow into the electric arc furnace and feeding electrical energy via at least one electrode into the electric arc furnace in order to melt the introduced material depending on a previously determined, necessary electrical energy input. The necessary electrical energy input into the arc furnace is determined depending on the mass flow input into the furnace.

Abstract: A converter for the production of steel by a blowing process from a substantially liquid raw material, in particular pig iron, includes several injectors which are dispersed in the sidewall of the converter about the converter inner circumference and directed towards the bath level for refining the pig iron. The injectors are designed as supersonic nozzle, which are surrounded by a ring nozzle forming an enveloping gas jet. The injectors are oriented at an angle of max. 43° in relation to the bath surface, with oxygen being introduced through the supersonic nozzle and a mixture of compressed air and natural gas being introduced through the ring nozzle. The jet pulse for the oxygen jet fed through the supersonic nozzle is dimensioned such that an infiltration of the oxygen jet into the melt bath is ensured.