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.

The present invention concerns a lance composed of a top lance (1t) and of a sublance (2) coupled to the top lance (1t), which forms a shoulder (1s) between the top lance and the sublance. The sublance (2) of the present invention is provided with a protective device (3) comprising a coupling end (2c) opening to the cavity (2v), wherein, when at rest, the protective device (3) is in an initial configuration characterized by an outer maximum diameter (D3o) which is not more than 10% larger than the diameter (D2) of sublance (2) (D3o≤1.1 D2), when the sublance (2) is coupled to the lance the protective device (3) contacts the shoulder (1s) and is deformed into a deformed configuration, forming a surface impervious to molten metal and slag, which spans over a whole area of the shoulder (1s).

The present disclosure provides a converter CO.sub.2—O.sub.2 mixed injection smelting method and a fire point area temperature dynamic control method. The method realizes online monitoring through an infrared temperature sensor installed inside an oxygen lance, dynamically adjusts the mixing ratio of CO.sub.2 and O.sub.2 and the height of the oxygen lance position according to the fire point area temperature changes and process requirements in different smelting stages, so that the secondary smelting system interlockingly and dynamically controls the fire point area temperature and the molten pool heating rate.

The present disclosure provides a converter CO.sub.2—O.sub.2 mixed injection smelting method and a fire point area temperature dynamic control method. The method realizes online monitoring through an infrared temperature sensor installed inside an oxygen lance, dynamically adjusts the mixing ratio of CO.sub.2 and O.sub.2 and the height of the oxygen lance position according to the fire point area temperature changes and process requirements in different smelting stages, so that the secondary smelting system interlockingly and dynamically controls the fire point area temperature and the molten pool heating rate.

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 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 invention relates to a method and an apparatus for controlling the pressure in the exhaust gas duct of a converter in a steel mill using a pressure control loop. To optimize the defined pressure setpoint for the pressure control loop so as to prevent excessive amounts of outside air from being drawn in via the converter mouth, the pressure setpoint is determined according to the invention by adapting a raw value based on the extent to which smoke or flames is/are formed at the mouth (120) of the converter (100).

The invention relates to a method and an apparatus for controlling the pressure in the exhaust gas duct of a converter in a steel mill using a pressure control loop. To optimize the defined pressure setpoint for the pressure control loop so as to prevent excessive amounts of outside air from being drawn in via the converter mouth, the pressure setpoint is determined according to the invention by adapting a raw value based on the extent to which smoke or flames is/are formed at the mouth (120) of the converter (100).

Improved processes and systems are disclosed for producing renewable hydrogen suitable for reducing metal ores, as well as for producing activated carbon. Some variations provide a process comprising: pyrolyzing biomass to generate a biogenic reagent comprising carbon and a pyrolysis off-gas; converting the pyrolysis off-gas to additional reducing gas and/or heat; reacting at least some of the biogenic reagent with a reactant to generate a reducing gas; and chemically reducing a metal oxide in the presence of the reducing gas. Some variations provide a process for producing renewable hydrogen by biomass pyrolysis to generate a biogenic reagent, conversion of the biogenic reagent to a reducing gas, and separation and recovery of hydrogen from the reducing gas. A reducing-gas composition for reducing a metal oxide is provided, comprising renewable hydrogen according to a hydrogen-isotope analysis. Reacted biogenic reagent may also be recovered as an activated carbon product. Many variations are disclosed.

The present invention concerns a lance composed of a top lance (1t) and of a sublance (2) coupled to the top lance (1t), which forms a shoulder (1s) between the top lance and the sublance. The sublance (2) of the present invention is provided with a protective device (3) comprising a coupling end (2c) opening to the cavity (2v), wherein, when at rest, the protective device (3) is in an initial configuration characterized by an outer maximum diameter (D3o) which is not more than 10% larger than the diameter (D2) of sublance (2) (D3o≤1.1 D2), when the sublance (2) is coupled to the lance the protective device (3) contacts the shoulder (1s) and is deformed into a deformed configuration, forming a surface impervious to molten metal and slag, which spans over a whole area of the shoulder (1s).