An improved apparatus for producing steel, including a lower furnace, an annular, water-cooled, fireproof lined cylindrical upper furnace, on which an upwardly closing conically tapering hat having openings can be placed. The smelting assembly is configured for the operational mode without melt flow and the operational mode with melt flow. To this end, at least one opening is provided in the conical furnace cover, through which opening at least one top lance can be introduced into the upper furnace. A plurality of sidewall injectors radially rotate around the cylindrical upper furnace in such a way that in a working position, the top lance and the sidewall injectors are directed onto a smelt level of a molten mass located in the lower furnace for refining.

A gas injection system includes a tubular wall 3 capable of being thermally stressed and having a proximal extremity and a distal extremity 11, at the distal extremity, at least one extremity opening through which at least one gas is projected. A cooling is system located in the tubular wall including axial channels 12 which extend axially towards the distal extremity and in which a cooling fluid is circulated. Connecting channels 13 circumferentially join the axial channels to each other at the distal extremity of the tubular wall. The connecting channels, which circumferentially join the axial channels at the distal extremity of the tubular wall, have a rounded shape in the direction of the distal extremity.

The invention relates to a process for injecting particulate material into a liquid metal bath wherein the liquid metal bath contains species to be oxidized, wherein the particulate material is carried to the liquid bath by means of a first gas stream. The solids injection rate is controlled such that the liquid bath temperature and/or the evolution of the liquid bath temperature is maintained within a pre-defined temperature range and the penetration depth of the first gas stream into the liquid bath is controlled by adjusting the flow of the first gas stream. At least one second gas stream is injected into the liquid, wherein the first and the second gas streams are an oxidizing gas, in particular oxygen, and the sum of the gas flows of the first and the second gas streams is determined based on the mass of the species to be oxidized and on the desired time for oxidizing the mass of the species.

A gas injection system includes a tubular wall 3 capable of being thermally stressed and having a proximal extremity and a distal extremity 11, at the distal extremity, at least one extremity opening through which at least one gas is projected. A cooling is system located in the tubular wall including axial channels 12 which extend axially towards the distal extremity and in which a cooling fluid is circulated. Connecting channels 13 circumferentially join the axial channels to each other at the distal extremity of the tubular wall. The connecting channels, which circumferentially join the axial channels at the distal extremity of the tubular wall, have a rounded shape in the direction of the distal extremity.

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.

A tuyere comprising an inner tube including a lower section having a first diameter, an upper section having a second diameter smaller than the first diameter, and a converging transition section having a converging angle Θ from 30° to 60° connecting the lower section to the upper section, the inner tube terminating in an inner nozzle at a downstream end of the upper section; and an outer tube surrounding the inner tube so as to create an annulus there between, the outer tube including a lower section having a third diameter larger than the first diameter, an upper section having a fourth diameter smaller than the third diameter but larger than the second diameter, and a converging transition section having connecting the lower section to the upper section, the outer tube terminating in an outer nozzle at a downstream end of the upper section.

A burner lance insert (1) for an electric arc furnace (2), includes a support body (3) that can be inserted into a wall opening (17) of the electric arc furnace (2). The insert has a front opening (5), a burner lance unit (7) which is mounted in the support body (3) in a rotatable manner about a rotational axis (A). A discharge channel (28) runs to a burner lance unit (7) discharge opening (29) lying in the front opening (5). A drive unit (9) rotates the burner lance unit (7) between two end positions in which the discharge opening (29) assumes different positions in the front opening (5) and the discharge channel (28) defines different discharge directions. The rotational axis (A) forms an angle between 30 degrees and 60 degrees, particularly preferably 40 degrees to 0 degrees, together with the direction of the gravitational force of the Earth after the support body (3) is inserted into the wall opening (17). The burner lance unit (7) is suitable for carrying out a burner operation as well as a lancing operation.

A tap hole cleaning apparatus (20) for an electric arc furnace and a corresponding electric arc furnace (1) enable the cleaning of a tap hole (12) of an electric arc furnace (1) comprising a furnace vessel (2) having an eccentric or offset bottom tap hole (12). A lance head (24) is movable in a first step from a lower end position to an upper end position into and through the tap hole (12), and in a second step, the lance head (24) is movable back through the tap hole (12) from the upper end position to the lower end position while ejecting oxygen through one or more lateral oxygen ejection nozzles to clean the inner periphery of the tap hole (12).

Methods for controlling the position of a lance supplying oxygen to a furnace containing a bath of molten metal. The methods include the steps of continuously detecting actual conditions associated with the furnace, continuously comparing the actual conditions to target parameters corresponding to the actual conditions, and continuously adjusting the position of the lance with respect to the furnace based on the comparison of the actual conditions to the target parameters.

Smelting metalliferous feed material process forming molten metal in smelting apparatus including smelt cyclone above and communicating with smelting vessel to contain molten metal and slag bath, including: partially reducing and melting feed material in smelt cyclone, allowing the molten partially reduced feed material flow downwardly into vessel, supplying oxygen-containing gas and carbonaceous material to vessel, smelting molten partially reduced feed material in molten metal and slag bath in vessel forming molten metal discharged from vessel and reaction products projected upwardly from molten bath, at least partially combusting combustible materials in reaction products in vessel space above molten bath, supplying oxygen-containing gas to smelt cyclone. Further combusting reaction products in smelt cyclone, discharging from smelt cyclone offgas including reaction products, supplying oxygen-containing gas into offgas duct upstream high temperature section combusting remaining offgas combustible materials while sufficiently hot for safe ignition and avoiding downstream burner-managed incineration.