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 method for treating molten metals (4) and/or slags in metallurgical baths comprises the introduction of a process gas into a melt bath. The process gas is accelerated to supersonic speed and is introduced below the melt bath surface (5) by means of at least one supersonic nozzle (6) with supersonic speed into the liquid phase of the molten metal (4) and/or into the slag and/or into the region of a phase boundary between molten metal and slag. The disclosure further relates to a metallurgical plant for treating molten metals.

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).

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 from 15 to 35 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.

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.

The object of the present invention is to improve the efficiency when operating the melting/refining furnace of the cold iron source using a burners and a lance, or during refining, and the present invention provides a method for operating a melting/refining furnace comprising a through hole so as to penetrate a furnace wall, at least one burners provided in the through hole; and at least one lances installed in an oxidant gas supply hole provided above the through-hole for the burner, wherein an amount of oxygen introduced in the melting step is adjusted to a range calculated based on a the furnace volume.

The invention relates to an aluminum scrap melting system (1) comprising a melting furnace (10) comprising a burner (20) which comprises an oxidant injector (23), and a fuel injector (25); a suction hood (30) intended to capture by suction the combustion fumes (F) and comprising a carbon monoxide sensor (37) configured to measure a carbon monoxide concentration (C) in said combustion fumes (F); and a control device (50) configured to receive an item of input information representative of the value of the carbon monoxide concentration (C), and to pilot the oxidant injector (23) and/or the fuel injector (25), according to said item of input information, the oxidant and fuel flows being piloted to contain the volatile organic compound content (VOC) at the output of the melting furnace at concentrations less than a safety value. The invention also relates to a process for melting aluminum scrap with such a melting system (1).

A coaxial dual supersonic oxygen flow cluster oxygen lance comprises an inner layer circular-hole supersonic nozzle assembly, an outer layer water-cooled casting assembly, and a middle layer annular-hole supersonic nozzle assembly arranged between the inner layer circular-hole supersonic nozzle assembly and the outer layer water-cooled casting assembly, wherein the circular-hole supersonic assembly generates a first beam of supersonic oxygen jets and the annular-hole supersonic assembly generates a second beam of supersonic oxygen jets surrounding the first beam of supersonic oxygen jets; and the second beam of supersonic oxygen jets and the first beam of supersonic oxygen jets are in the same direction, and the two beams of supersonic oxygen jets are independently supplied with gas, and are independently adjusted. The oxygen lance can form coaxial dual supersonic oxygen flow, can flexibly adjust the flow of the oxygen lance under the condition of supersonic jets, and can meet the different requirements of an electric furnace at high steel scrap ratio for an oxygen system during smelting periods at different working conditions, thereby improving smelting efficiency of the electric furnace, reducing consumption and shortening smelting periods.

A method for supplying energy to a scrap metal pile (9) in an electric arc furnace (2). Energy is supplied by jets of hot gas in a first phase. Energy is supplied by electric arcs in a second phase after the first phase is completed. Hot gas is supplied via at least six jets. A device (1) for the method has an electric arc furnace (2), one or more blowing devices (6a, 6b, 6c), supply jets of reactant hot air into the chamber (7) of the electric arc furnace (8). The devices have a total of at least six nozzles (10a, 10b, 10c, 10d, 10e, 10f) with nozzle openings. Fuel conducting devices (8) supply fuel to the jets of reactant hot air.

A method of operating a smelt cyclone, wherein the supply of feed material and/or the supply of oxygen containing gas through an array of tuyeres into the smelt cyclone is controlled in order to control accretions of metalliferous feed material at the inside of the smelt cyclone.