345 results about "Direct reduced iron" patented technology

The invention belongs to the technical field of ironmaking, and particularly discloses a method for producing titanium-rich direct reduction iron and high-titanium slag by using vanadium titano-magnetite, which comprises the following steps: preparing vanadium titano-magnetite raw ore into vanadium-titanium-iron concentrate powder and titanium concentrate powder, mixing the vanadium-titanium-iron concentrate powder and the titanium concentrate powder with a binder to prepare iron-titanium concentrate composite green pellets, and oxidizing and roasting to obtain the titanium-rich direct reduction iron and high-titanium slag with the compressive strength of more than 2000N / pellet and the compressive strength of more than 2000N / pellet. The reduction expansion rate of the iron-titanium concentrate composite high-titanium pellets is smaller than 20%; the iron-titanium concentrate composite high-titanium pellets are subjected to a direct reduction reaction in a shaft furnace, and titanium-rich direct reduced iron with the metallization ratio larger than or equal to 85% is obtained; and molten iron and high-titanium slag are obtained after the obtained titanium-rich direct reduced iron is subjected to melting separation through a melting separation electric furnace. According to the method, the iron-titanium concentrate composite high-titanium pellets meeting the direct reduction smelting requirement of the gas-based shaft furnace are prepared and applied to the gas-based shaft furnace for direct reduction production of the titanium-rich direct reduction iron, high-quality titanium-rich raw materials can be provided for smelting titanium slag in a melting electric furnace, and the problem that the recovery rate of titanium resources in existing vanadium titano-magnetite is low is effectively solved.

The invention belongs to the technical field of steel smelting, and particularly discloses a comprehensive utilization method of vanadium titano-magnetite, which comprises the following steps: S1, preparing the vanadium titano-magnetite into pellets, and carrying out reduction reaction to obtain direct reduced iron; s2, a carbonaceous reducing agent and the direct reduced iron obtained in the step S1 are mixed and smelted in a melt separation electric furnace, and slag and molten iron are obtained; a slag former is not added in the smelting process, the purity of the titanium slag is improved through optimal design of the furnace profile of the melting electric furnace and combination of various smelting process control means, the problems that refractory materials of the melting electric furnace are excessively eroded, the service life is short, slag-metal separation is difficult, smelting is difficult to control and the like are solved, and the purposes of high-grade titanium slag and long service life of the melting electric furnace are achieved.

The invention relates to the technical field of smelting, in particular to a preparation method of direct reduction iron. The preparation method of the direct reduced iron comprises the following steps: by taking high-temperature and high-pressure hydrogen-rich synthesis gas generated by gasifying a biomass raw material as reducing gas, reducing pellets containing medium-low-grade iron ores to obtain the direct reduced iron, the high-temperature and high-pressure hydrogen-rich synthesis gas comprises H2 and CO; when the molar fraction of H2 is 50% < = XH2lt; when the content is 65% and the molar fraction of CO is 30%-45%, the reduction reaction temperature is 900-950 DEG C; when the molar fraction of H2 is 65% < = XH2lt; when the molar fraction of CO is 90% and the molar fraction of CO is 5%-30%, the reduction reaction temperature is 850-900 DEG C; when the molar fraction XH2 of H2 is greater than or equal to 90%, the reduction reaction temperature is 800-850 DEG C; the method can realize direct reduction of hydrogen groups of medium-low-grade iron ores, and is low in energy consumption and less in carbon emission.

The invention belongs to the technical field of ironmaking and steelmaking, and particularly discloses a direct reduction iron production process and system of variable feed gas. The production process comprises the following steps: under a basic working condition, a hydrogen-rich working condition or an all-hydrogen working condition, introducing high-temperature reducing gas into a shaft furnace to produce the direct reduced iron; the production system comprises a shaft furnace, a self-heating modification device, an upgrading device, a heating furnace and a preheating furnace, and is provided with three hydrogen supplementing points and two hydrogenation points. By changing the structure of the raw material gas, supplementing hydrogen at three positions or supplementing or adding hydrogen at at least one of two hydrogenation points, increasing the H2 content of the reducing gas at the inlet of the shaft furnace and the like, the carbon emission, the process energy consumption and the pellet reduction difficulty are reduced.

The invention discloses a smelting method of a green invar alloy. The smelting method specifically comprises the following steps: adopting an electric arc furnace smelting, LF (ladle furnace) refining and VD (vacuum degassing) oxygen control and nitrogen increase triple smelting process; in the electric arc furnace smelting process, directly reducing iron within 30% is added, and the remaining proportion is scrap steel; in the LF refining process, precious metals such as a nickel plate, ferromolybdenum and ferrovanadium are added for alloying operation; and a gaseous nitrogen increasing process is adopted in the VD smelting process. According to the method, direct reduction iron and waste steel are adopted as raw materials of the electric arc furnace, the carbon emission in the smelting process is greatly reduced, the requirement for environmental protection is met, the gaseous nitrogen increasing technology is adopted in the VD process, precious nitroalloy raw materials do not need to be used, the smelting cost is reduced, energy consumption is reduced, and the steel grade is rich in'green steel 'labels.

The invention discloses a method for smelting direct reduction iron through an electric furnace. The method comprises the following steps that S1, a direct reduction iron raw material with the high carbon content is obtained through a shaft furnace; s2, a molten pool is firstly formed in the electric furnace; s3, the direct reduction iron raw materials are added into an electric furnace molten pool in batches for electric furnace smelting; in each charging process, a direct reduction iron raw material is firstly put into an electric furnace molten pool, then scrap steel is put into the electric furnace molten pool to press the direct reduction iron into the molten pool, lime is added after the direct reduction iron is completely molten, and then charging is continued; and S4, after melting in the electric furnace molten pool is completed, blowing oxygen to stir the molten pool for continuous smelting until carbon in the molten steel reaches the standard. The melting efficiency of the direct reduction iron can be improved, and the power consumption cost is reduced.

The invention discloses a converter smelting method using direct reduced iron, which comprises the following steps of: (1) adding the direct reduced iron into a converter along with scrap steel according to the adding amount of 10-150kg / t; (2) carrying out blowing operation; the lance position of an oxygen lance for blowing for 0-5 min is 1500-2200 mm, the added coolant is less than or equal to 15 kg / t, and the slag former is less than or equal to 60 kg / t; the lance position of an oxygen lance for blowing for 5-10 minutes is 1700-2500mm, the added coolant is less than or equal to 30kg / t, and the slag former is less than or equal to 20kg / t; the lance position of an oxygen lance after blowing for 10 minutes is 1300-2000 mm, the added coolant is less than or equal to 10 kg / t, and the slag former is less than or equal to 10 kg / t. According to the method, the direct reduction iron is added into the converter along with the waste steel, and by controlling the adding amount and the smelting process, it is guaranteed that decarburization and temperature rising reactions in the converter are normally carried out, and the abnormal conditions such as dry returning and waste steel non-melting are avoided. After the method is adopted, the converter blowing process is stable, the dry returning and splashing conditions are avoided, the scrap steel is completely molten, and smooth converter smelting is effectively guaranteed while the carbon emission of the whole process is reduced.

The invention discloses a method and system for directly reducing iron ore powder through a gas-based multi-hearth furnace, and the method comprises the steps that the iron ore powder and reducing gas are subjected to a reduction reaction in a multi-hearth furnace reactor, and reduced metal iron is obtained; the reducing gas is H2 and / or CO, and the reduction temperature is 700-800 DEG C. According to the method and the system, a multi-hearth furnace is adopted, material flow and high-temperature gas are subjected to countercurrent heat convection exchange reaction from top to bottom through a mechanical transmission device, and the method and the system have the advantages of large hearth area, multiple gas-solid interfaces, long retention time of materials in the furnace, high reduction efficiency and the like; the method is suitable for treating powder substances with low heat value. According to the method and the system, the iron ore powder is directly reduced through the multi-hearth furnace, a pelletizing step necessary for an existing hydrogen-based shaft furnace reduction method is omitted, the problem of particle bonding and flow loss of a fluidized bed hydrogen reduction method is effectively solved, and the method and the system have the advantages of low CO2 emission, low energy consumption, high product metallization ratio and the like.

The invention provides a biomass gasification coupling iron ore powder reduction device and method with CO2 circulation, and relates to the technical field of direct reduction of iron from biomass gasification products. The biomass gasification coupling iron ore powder reduction device with CO2 circulation comprises a biomass gasification reaction device and a circulating fluidized bed reduction reaction device. The method comprises a method of a biomass gasification reaction device and a method of a circulating fluidized bed reduction reaction device. Through structural arrangement and application of the biomass gasification reaction device and the circulating fluidized bed reduction reaction device, CO2 gas circulation, zero carbon emission and high-purity iron raw material efficient utilization preparation can be achieved; the preparation method is simple and easy to operate, green and environment-friendly, low in cost, short in process, high in efficiency and beneficial to industrial large-scale production and popularization.

The invention provides a smelting electric arc furnace and system, and relates to the technical field of smelting equipment, the smelting electric arc furnace comprises a furnace body, an electrode assembly, a furnace door and a pressing mechanism, and the furnace body is provided with a feeding port, a smoke outlet, a bottom blowing port, a slag outlet and a steel outlet; the electrode assembly comprises at least one first electrode; the furnace door is arranged on the furnace body in an openable manner; the pressing mechanism comprises a pushing head and a connecting piece connected with the pushing head, when the furnace door is located at the opening position, the connecting piece can drive the pushing head to stretch into the furnace body through the furnace door, and the pushing head can be used for pressing raw materials floating on a molten pool in the furnace body into the molten pool. Compared with the prior art, the direct reduction iron (DRI) raw material floating on the molten pool can be pressed into molten steel, the number of the direct reduction iron (DRI) raw material floating on the molten pool is reduced, the metal recovery rate of the direct reduction iron (DRI) is further increased, the air sealing structure can play an air sealing role on the furnace body in the smelting process, and therefore production of low-nitrogen steel is achieved.

The present invention discloses a method for reducing the hydrogen-rich reduction swelling of pellet ore based on stepwise reduction in a hydrogen-based shaft furnace, belonging to the technical field of direct reduced iron production. The pellet ore is successively reduced in the first-stage hydrogen-based shaft furnace (temperature: 780 - 880 °C, volume fraction of H2 + CO > 80%, and volume ratio of H2 / (H2 + CO) is 0.6 - 0.8) and the second-stage hydrogen-based shaft furnace (temperature: 980 - 1040 °C, volume fraction of H2 + CO > 90%, and volume ratio of H2 / (H2 + CO) ≥ 0.8), and then cooled to obtain direct reduced iron. This method can reduce the maximum reduction swelling rate of the entire pellet ore during the reduction process to less than 10% without using pellet additives such as calcium and magnesium. While ensuring the reduction efficiency of the hydrogen-based shaft furnace, it can produce direct reduced iron with quality indicators meeting the requirements and higher iron grade, which is conducive to realizing the clean, efficient, and short-process utilization of iron ore resources.

The present disclosure provides a system and a method for steel synthesis using green hydrogen by coupling renewable energy and Carnot batteries with Solid-Oxide Electrolyser Cells (SOEC) and carbon capture. The system provides an end-to-end, geography-agnostic solution for steel synthesis with green hydrogen with round-the-clock renewable energy using Carnot battery that provides both heat and power to run an SOEC at a high efficiency. The hydrogen from the SOEC may be used for direct reduction of iron followed by steel synthesis in an Electric Arc Furnace. The heat from the SOEC is also used for capturing CO2 from the exhaust gases (or air in the DAC configuration). The captured CO2 may be used for electrofuels synthesis along with green hydrogen or electrochemically reduced to carbon. The process heat from DRI and EAF is recycled back to the Carnot batteries.

The invention discloses a thermal compensation system and method for producing direct reduced iron (DRI) by using a pure hydrogen shaft furnace. The thermal compensation system comprises the shaft furnace, a DRI cooling tower, a 1 # heat exchanger, a 2 # heat exchanger and a feeding device, a DRI outlet of the shaft furnace is communicated with a DRI cooling tower; a hydrogen pipeline is communicated with a hydrogen inlet of the DRI cooling tower, and a hydrogen outlet of the DRI cooling tower is communicated with a process gas inlet of the shaft furnace through a heat exchange passage of the 1 # heat exchanger; a furnace top gas outlet of the shaft furnace is communicated with a process gas inlet of the shaft furnace after passing through a heat exchange passage of the 2 # heat exchanger; and a nitrogen pipeline is sequentially communicated with the other heat exchange passage of the 1 # heat exchanger and the other heat exchange passage of the 2 # heat exchanger and then is communicated with the feeding device. According to the system and the method, heat of the hot-state DRI and the furnace top gas can be effectively utilized to preheat the raw materials entering the furnace, the utilization efficiency of heat energy and hydrogen is fully improved, and low-carbon and even zero-carbon ironmaking is practically achieved.

The invention discloses a method for inhibiting abnormal expansion of ultrahigh-grade pellets through gradient heating reduction of a hydrogen-based shaft furnace, and belongs to the technical field of direct reduction iron production. The method comprises the following steps: continuously adding ultrahigh-grade pellets from the top of a hydrogen-based shaft furnace, and sequentially passing through a first heating reduction zone (the heating speed is 10-20 DEG C / min, and the temperature reaches 900-930 DEG C), a second heating reduction zone (the heating speed is not less than 30 DEG C / min, and the temperature reaches 990-1020 DEG C), a constant-temperature reduction zone and a cooling zone of the hydrogen-based shaft furnace to obtain the direct reduction iron. The method is suitable for the hydrogen-based shaft furnace with various reducing atmospheres, the maximum reduction expansion rate of the ultrahigh-grade pellets in the reduction process of the hydrogen-based shaft furnace can be smaller than 15% on the premise that the original iron grade of the pellets is not reduced, high-purity direct reduction iron with qualified production indexes is produced, and reduction of follow-up electric furnace smelting energy consumption and the molten iron refining process are facilitated.

The invention discloses a smelting method of cold direct reduced iron in a Consteel electric furnace, belonging to the technical field of electric furnace steelmaking. The smelting method comprises the following steps: at the beginning of smelting, low-grade power supply is adopted, and at the same time of power-on, oxygen lances and carbon lances on the furnace wall are used to blow oxygen and spray carbon to produce foamed slag for submerged arc. After 1-3 minutes, scrap steel is continuously added by the Consteel system, and cold direct reduced iron is added through the fifth hole of the electric furnace. The molten steel in the furnace is heated by the electric arc, and the molten steel melts the metal materials in the furnace; during the whole smelting process, lime and light burned dolomite are added in batches. The addition amount of lime is 30-50 kg / t of steel, and the addition amount of light burned dolomite is 25-30 kg / t of steel. The invention helps to maintain the whole-process flat bath smelting, reduce the power consumption of electric furnace smelting, and reduce the smelting cost; it provides a technical solution for a short-process demonstration plant for the efficient use of direct reduced iron in an electric furnace, filling the domestic technical research gap in the short-process industry of electric furnaces.

Disclosed herein, in some aspects, are systems and methods for producing a material comprising iron through self-reduction of iron ore using bio-oil and / or other reducing agents (e.g., bio-based reducing agents), such as biocrude, ethanol, or other bio-based liquids or biologically sourced liquids. The bio-oil and / or other reducing agents can be mixed with the iron ore to form a furnace mixture, which can be heated, such that the components of the bio-oil and / or other reducing agents in the furnace mixture reduce the iron ore to form an iron product (e.g., a material that includes metallic iron). In some cases, the pre-formed furnace mixture allows for the reducing agents to interact with the iron more readily, thereby providing for quicker reaction rates, and thereby quicker reduction of iron ore, as compared to direct reduction iron production.

The invention relates to a hydrogen metallurgy supplementary heating device which comprises a heat exchanger, a microwave heating device and a pressure swing adsorption device, the pressure swing adsorption device is located on a gas communication pipeline between a secondary hydrogen metallurgy reactor and a primary hydrogen metallurgy reactor, and the heat exchanger is arranged between the pressure swing adsorption device and the primary hydrogen metallurgy reactor. A treated exhaust gas pipeline of the pressure swing adsorption device is connected with the microwave heating device, a treated product gas pipeline of the pressure swing adsorption device is connected with the heat exchanger, and an outlet pipeline of the microwave heating device is connected with the heat exchanger. The hydrogen is dehydrated and purified through the pressure swing adsorption device, and the part of byproduct water vapor is heated by microwave to heat the dehydrated and purified hydrogen, so that the dehydrated and purified hydrogen reaches the temperature required by direct reduction of iron ore, and the continuous and efficient reduction reaction of the hydrogen metallurgy reactor is promoted.

The invention provides an electric furnace which comprises a furnace tank, the furnace tank comprises a push head assembly and a heating part, the push head assembly is arranged at the top of the furnace tank and provided with a push head part capable of being movably arranged in an inner cavity of the furnace tank in a penetrating mode in the vertical direction, and the heating part is attached to the outer side of the furnace tank in the circumferential direction of the furnace tank; the negative pressure feeding mechanism comprises a feeding structure and a horizontal feeding structure, the feeding structure is provided with a transfer box body, an air extraction assembly capable of extracting air and a feeding pipeline used for conveying smelting materials, and one end of the feeding pipeline and the air extraction assembly are in sealed communication with an inner cavity of the transfer box body; the other end of the feeding pipeline is communicated with an inner cavity of the furnace tank in a sealed mode, a feeding port is formed in the transfer box body, the horizontal feeding structure is provided with a horizontal feeding section capable of conveying smelting materials through vibration, and the horizontal feeding section is connected with the feeding port and communicated with an inner cavity of the transfer box body through the feeding port. The problems that the metal yield of direct reduction iron is low, and the nitrogen content in molten steel is high are solved.

The invention provides a process for directly reducing iron and separating iron and aluminum from aluminum oxide red mud, and relates to the technical field of comprehensive utilization of metallurgical solid waste such as red mud and carbon dioxide CCUS. According to the process for directly reducing iron and separating iron from aluminum by using aluminum oxide red mud, solid wastes such as red mud, secondary aluminum ash or other sodium-based additives, metallurgical slag and the like are used as raw materials, and are mixed and granulated after being reasonably matched with a catalyst. Roasting in a gas semi-suspension oxidation kiln; and the roasted material enters a self-gravity closed electric heating reduction kiln to be calcined by taking biomass as fuel. CO gas generated by calcination is used as fuel of the fuel gas semi-suspension oxidation kiln. After calcination, under the protection of excessive CO gas, the high metallization ratio of 95% or above is achieved, iron and aluminum are separated, the material cooled to about 200 DEG C is leached with water, the levigated material enters a magnetic separator, solid-liquid separation and solid-phase magnetic separation of metal iron are achieved, and titanium concentrate and slag are separated.

The invention discloses a high-sulfur iron ore concentrate pellet desulfurizing agent and a method for strengthening high-sulfur iron ore concentrate pellet desulfurization, and belongs to the technical field of iron ore pellet production. The high-sulfur iron ore concentrate pellet desulfurizing agent comprises calcium peroxide powder, direct reduction iron powder dust and manganese dioxide powder, the desulfurizing agent participates in pyrite-containing iron ore pelletizing, obtained green pellets are sequentially subjected to forced air drying, preheating and roasting, and finished pellets are obtained. According to the method, the desulfurization efficiency of the high-sulfur iron ore concentrate pellets in the drying and preheating process can be remarkably improved through the desulfurizer, and meanwhile the technical problem that the pellet strength is reduced due to the fact that a large amount of SO2 is adsorbed when the pellets are dried and sulfate shells are formed on the surfaces of the pellets can be solved by removing air draft drying. The method is simple to operate, low in production cost and environment-friendly, and meets the requirements of industrial production.

A steel manufacturing method includes the steps of producing direct reduced iron in a direct reduction plant (1) using a syngas (70) resulting from the gasification of solid waste fuels, producing hot metal (22) and a blast furnace top gas (21) in a blast furnace (2) using a hot blast (20), the blast furnace top gas (21) being at least partly (21A) used into the direct reduction plant (1) and producing molten metal and electric furnace gas in an electric furnace (3) using the produced direct reduced iron (12). Associated network of plants.

The invention relates to the technical field of comprehensive utilization of resources, in particular to a comprehensive utilization method of iron ore. The comprehensive utilization method of the iron ore comprises the following steps: S1, preparing the iron ore into pellets and carrying out reduction reaction to obtain direct reduced iron; s2, the direct reduction iron is smelted, melt separation slag and molten iron are obtained, and the content of ferrous oxide in the melt separation slag is 1 wt%-4 wt%; and S3, directly preparing the melt separation slag into the rock wool on line when the melt separation slag is hot. Different from the prior art, the carbonaceous reducing agent is added in the smelting process, the content of ferrous oxide in the obtained melt separation slag is reduced, the heat preservation performance and the tensile mechanical performance of the prepared rock wool are improved, then the energy-saving effect, durability and safety of the rock wool are improved, meanwhile, the yield of obtained metal is increased, and the molten iron yield is increased; and the economic benefit is improved.

This application relates to the field of steel production technology, and in particular to a method and apparatus for evaluating the flexibility of a hydrogen-based shaft furnace. The method includes: establishing a time-domain dynamic simulation model of the hydrogen-based shaft furnace to obtain production time-domain data; constructing an initial flexibility model of the hydrogen-based shaft furnace considering the direct reduction iron metallization rate based on the first-order dynamic reaction process of the furnace; adjusting the initial flexibility model using the production time-domain data to obtain a final discretized flexibility model; and integrating the discretized flexibility model into the objective function of the hydrogen-based shaft furnace under real-time electricity prices to obtain the flexibility evaluation result. This solves the problem that related technologies often use steady-state models, which are difficult to characterize the dynamic evolution of the furnace's temperature field, gas concentration field, and reaction process under operating condition disturbances such as load changes, hydrogen supply fluctuations, and changes in raw material properties, easily leading to deviations between model predictions and actual operating conditions.

The invention relates to a process for smelting molten iron for converter steelmaking by using hydrogen-based shaft furnace direct reduction iron. The process comprises the following steps: 1) smelting raw materials comprise direct reduction iron, coke powder and lime; and (2) after the smelting raw materials enter the furnace, a material accumulation area is formed between the electrode and the furnace lining, the height of the accumulation area is larger than the length of an electric arc generated by the electrode, and the distance between the bottom of the electrode and the liquid level of molten iron is kept to be 200-300 mm. And 3) continuously supplying power to the electrodes, continuously melting the smelting raw materials, and forming a molten iron layer, a slag layer and a raw material layer at the furnace bottom from bottom to top. And (4) the pressure in the furnace is controlled within 0-100 pa. And (5) the molten iron generated by the electric furnace and the slag are regularly discharged in a slag-iron mixing mode. According to the method, a blast furnace ironmaking process is not used, and the direct reduced iron produced by hydrogen-based shaft furnace smelting is directly used as a main raw material to smelt the molten iron, so that the possibility that the hydrogen-based reduced iron is used for converter steelmaking on a large scale is provided.

The invention relates to production equipment and a production method for preparing direct reduced iron. According to the method, all components in the raw coke oven gas and sensible heat of the reduced pellets are fully utilized, the raw coke oven gas and the treated coke oven gas are used for preparing the direct reduction iron together, and the method has the advantages of being simple in process, low in energy consumption and the like.

The application discloses a method for preparing Fe-CaTiO3 heterogeneous visible light Fenton catalyst from vanadium-titanium magnetite, and comprises the following steps: (1) vanadium-titanium magnetite powder, bentonite, slaked lime and water are mixed according to a proportion, and then enter a disc balling machine to be balling to prepare green balls; (2) the green balls prepared in the step (1) are dried and roasted to prepare oxidized pellets; (3) the oxidized pellets are reduced in a hydrogen-rich reducing atmosphere to obtain direct reduced iron (DRI) containing CaTiO3; (4) the DRI is cooled to below 50 DEG C under the protection of inert gas; and (5) the cooled DRI is crushed and ball milled, and thus Fe-CaTiO3 is obtained. The prepared Fe-CaTiO3, H2O2 and visible light constitute a photo-assisted heterogeneous Fenton reaction system, which can efficiently catalyze degradation of organic pollutants in wastewater; and the method has the advantages of low preparation cost, high catalytic activity, easy recovery and reusability.

The invention relates to a method for heating DRI (abbreviation for "direct reduced iron", also referred to as sponge iron) between a direct reduction plant and a further-processing plant, wherein the DRI (2) is conducted in the form of a DRI stream (3) from the direct reduction plant to the further-processing plant by means of a line arrangement (1) and the line arrangement (1) has one or more induction coils (4) in the form of a heating element for contactless heating of the DRI stream (3) conducted through the line arrangement (1), wherein the induction coil (4) or the induction coils (4) is / are operated with alternating current. The invention is characterized in that a frequency of at least 10 kHz is specified and / or set as the frequency of the alternating current.

1. A direct iron ore reduction process, in which an NH3-containing gas feed (24a) is fed to a gas reformer (25) where it is reformed to obtain a hydrogen-containing reducing gas (25a, 25b), at least a portion of which is fed to a direct reduction reactor (1) where iron ore (2) is subjected to direct reduction with the reducing gas (25a, 25b) to obtain directly reduced iron (30), and during reforming of the hydrogen-containing reducing gas (25a), NH3 in the gas feed (24a) is subjected to the dissociation reaction 2NH3 → N2 + 3H2.

Provided is a reduced iron production method that can suppress clustering of iron ore pellets. A reduced iron production method according to the present invention is characterized by comprising: a pellet production step for mixing an iron ore powder, a binder, and an auxiliary material, granulating the mixture to obtain green pellets, and baking the green pellets to obtain iron ore pellets; and a reduction step for charging the iron ore pellets in a vertical shaft furnace, and directly reducing the same by using a reducing gas to obtain reduced iron pellets. The reduced iron production method is characterized in that: raw materials of the iron ore powder include an iron ore having a compositional makeup in which the total Fe amount is 63 mass% or less and the sum of SiO2 and Al2O3 is 4 mass% or more; and the reduced iron pellets satisfy the following formula. (SiO2+Al2O3+CaO+MgO+FeO) / M.Fe ≥ 0.15

The disclosure relates to a process for producing molten iron or an alloy thereof from low- carbon direct reduced iron (DRI) in an electric arc furnace (EAF). The DRI comprises less than 0.1 wt% carbon. The process comprises a combined charging and melting stage comprising continuously charging DRI to a molten metal bath in the EAF and concurrently operating the EAF to continuously melt the DRI. During this stage, the process is maintained within the following operational window - bath temperature of from about 1580 °C to about 1750 °C; - FeO in slag of from about 25 wt% to about 40 wt%; - slag B2 basicity of from about 1.5 to about 3.5, wherein the B2 basicity is calculated as (wt% CaO) / (wt% SiO2); - MgO in slag of from about 8 wt% to about 13 wt%; and - carbon monoxide (CO) in offgas > 26 Nm3 / h / m2.