202 results about "Direct reduced iron" patented technology

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 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 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 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 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.

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.

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 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.

1. A method for hot rolling steel, comprising: i. smelting steel scrap containing at least one of the following residual elements: Mo, Sn, Sb, As, and optionally hot metal from a blast furnace and / or direct reduced iron, to a theoretical hot rolling temperature T HR_TH ii. estimating the composition of the molten steel; iii. casting a semi-finished product with the molten steel; and iv. determining the minimum hot rolling temperature increase, T, that can offset the presence of the residual elements: Mo, Sn, Sb, and / or As. OFFSET and v. defining the temperature T HR hot rolling at T HR =T HR_TH +T OFFSET and

The invention discloses a coal-based tank-type ball block direct reduction iron canning device, and relates to the field of environmental protection equipment, the coal-based tank-type ball block direct reduction iron canning device is characterized in that a shell is fixedly connected with a vertical plate, the vertical plate is fixedly connected with a mounting plate, the mounting plate is provided with a group of uniformly distributed mounting holes, the shell is fixedly connected with symmetrical cylinders, and the cylinders are fixedly connected with the vertical plate. The symmetrical cylinders are respectively provided with an opening, the symmetrical cylinders are respectively and fixedly communicated with a discharging pipe, the shell is provided with a groove body, the symmetrical openings are respectively communicated with the groove body, the symmetrical cylinders are respectively and fixedly connected with round head shells, the shell is fixedly connected with a first vertical rod, the shell is fixedly connected with a gear protection shell, and the gear protection shell is fixedly connected with a second vertical rod. The vertical plate is fixedly connected with the first transverse plate. The technical problem to be solved by the invention is to provide the coal-based tank-type ball block direct reduction iron canning device which has the characteristics of simple structure, reliability, practicability, reduction of stations of the canning device, low investment, improvement of the mechanization and automation degree of a production line, reduction of the amount of labor and the like.

The present invention relates to a method for producing hot metal in an electric smelting furnace 13, comprising the following consecutive steps: - providing a direct reduced iron product 12, - providing a carbon and iron-containing material 30, - alternately feeding the DRI product 12 and the carbon and iron-containing material 30 to at least a part of the smelting furnace, - melting the DRI product 12 and the carbon and iron-containing material 30 to produce hot metal 14. The present invention also relates to the production of steel from said hot metal.

A direct reduction system for a direct reduction of iron ore, comprising a reactor having a reduction area and being adapted to be loaded from above with said iron ore; a treatment and feeding line, to process the process gases, thus obtaining a reducing gas mixture, and feed said reducing gas mixture into the reduction area; a line for recovering and treating an exhausted gas exiting the reactor, communicating upstream with the reactor and downstream with said treatment and feeding line; wherein at least one bypass duct is provided, adapted to divert at least one portion of reducing gas mixture from said treatment and feeding line to said recovery and treatment line.

A system and method for process water and oxide coating recovery and distribution in a direct reduction system, such as a system for producing direct reduced iron. A warm lime softener is used to remove (recover) calcium, alkalinity, and other constituents from the process water system and to produce an effluent that can be further processed and returned as makeup to the process water system. The lime softening process requires lime (or similar material) to be added to the influent, thereby increasing the calcium and pH levels until they become supersaturated and precipitate. This chemical process results in effluent that is low in calcium, alkalinity, and total suspended solids.

The invention discloses a short-process method for preparing raw material pure iron by directly reducing iron, and belongs to the technical field of metallurgy. According to the method, direct reduction iron with the metallization ratio larger than or equal to 92% serves as a main raw material (the proportion is larger than or equal to 60%), pure waste steel and slagging materials are added, electric arc furnace inert gas protection smelting (segmented power supply, multi-stage slagging phosphorus, oxygen and sulfur removal and oxygen blowing decarburization till [C] is smaller than or equal to 0.025%) is carried out, further decarburization ([C] is smaller than or equal to 0.01%) is carried out through VOD refining, deoxidation alloying is carried out, and finally continuous casting blank forming is carried out in the whole process. The obtained raw material pure iron meets the GB / T 9971-2017 standard, the process is short, slag and iron separation is thorough, and the raw material pure iron can serve as furnace charge of high-end products such as precision alloy and high-temperature alloy.

1. A method for producing direct reduced iron, in which iron ore is reduced in a DRI shaft by a reducing gas comprising hydrogen obtained by extraction from coke oven gas through a hydrogen separation unit, and a remaining portion of such coke oven gas is at least partially injected into a transition section of the DRI shaft to set the carbon content of the direct reduced iron to 0.5-3 wt. %, as well as a DRI production plant comprising a DRI shaft (1) and a hydrogen separation unit (5), the inlet of which is connected to a coke oven gas source (6), a first outlet connected to the DRI shaft for injecting hydrogen separated from the coke oven gas, and a second outlet connected to a transition section of the DRI shaft (1) for injecting at least a portion of the remaining portion of such coke oven gas.

The present application belongs to the field of comprehensive utilization of resources, and particularly relates to a method for preparing phosphorus-rich direct reduced iron from high-phosphorus iron ore. The present application aims at the problem of serious phosphorus volatilization in the existing reduction roasting process. By adding a proper amount of Al2O3 to the high-phosphorus iron ore, the molar ratio of Al to Si in the system is 0.8-1.2; reduction roasting is carried out at 1200-1400 DEG C, which can promote the aggregation of phosphorus in the liquid phase in the direct reduction roasting process, and then the reduced metallic iron absorbs it, inhibits the gasification loss of phosphorus, and realizes the direct utilization of high-phosphorus iron ore as raw material and the effective enrichment of phosphorus in the direct reduced iron. The present application can finally obtain phosphorus-rich direct reduced iron with iron grade greater than 90.0%, magnetic separation iron recovery rate greater than 80.0%, and phosphorus content of about 1.2%-2.5%, and realize the enrichment of more than 80% of phosphorus in the ore to the direct reduced iron. The process method of the present application is simple, the resources are fully utilized, and has a wide application prospect.

A shaft furnace for the direct reduction of iron includes a central flowpath defined by an innermost portion and a peripheral flowpath defined by another portion circumscribing the central flowpath, each extending from a top feed system to a transition zone or cooling zone below the reduction zone at a bottom of the shaft furnace. The central flowpath receives a distinct first flow of iron oxide and discharges a distinct first flow of reduced iron to the transition zone or cooling zone. The peripheral flowpath receives a distinct second flow of iron oxide and discharges a distinct second flow of reduced iron to the transition zone or cooling zone. A central reducing gas inlet and a peripheral reducing gas inlet of the shaft furnace are configured to, respectively, receive and counterflow a distinct first reducing gas within the central flowpath and a distinct second reducing gas within the peripheral flowpath.

The invention relates to a device for stabilizing the metallization ratio of direct reduction iron and a use method. The device is connected with a discharge port of the fluidized bed and comprises a rotary sealing valve, an air bellow, a grate net, a heat exchanger, a fan, a cyclone separator, a storage bin, a lower outlet of the air bellow, a temperature measuring device and a flow measuring device, the discharge port of the fluidized bed is connected with the air bellow, the rotary sealing valve is arranged on a pipeline, the fan is arranged at the bottom of the air bellow, and the heat exchanger is arranged between the air bellow and the fan. An upper outlet of the air bellow is connected with an inlet of the cyclone separator, a storage bin a is arranged at an outlet of the cyclone separator, a grid mesh is obliquely arranged in the air bellow, a lower outlet of the air bellow is arranged at the tail end of the grid mesh and connected with the inclined chute, and a storage bin b is arranged at an outlet of the inclined chute. According to the method, the wind power is calculated and adjusted, so that the obtained final product is the direct reduced iron with the set target metallization ratio or above.

The present disclosure provides systems and methods for iron production as well as apparatuses useful in such systems and methods. Metallic iron is produced in a DRI furnace into which is introduced raw iron (iron oxides) and a syngas. The syngas is formed using a first processing unit, such as a CO2 convective reformer (CCR), and optionally a second processing unit, such as an oxygen secondary reformer (OSR), to react a hydrocarbon with a reformant to form syngas with substantially complete carbon capture. Top gas from the DRI furnace may be used in a combustor as a fuel to form a heated exhaust stream that is used to provide reaction heating to the first processing unit, and the exhaust stream received from the first processing unit may be further processed so that at least a portion of the exhaust stream may be recycled to the combustor.

To provide a new method for producing steel without discharging carbon dioxide at all in a process for producing steel from iron ore.SOLUTION: In a method, iron ore 1 is melted in an electric furnace 2 at a temperature of 1550°C or higher, and then oxygen in an iron ore bath is removed by spraying hydrogen to the iron ore bath surface using a high-speed hydrogen jet stream from above the electric furnace or a refining furnace separately provided, or by introducing hydrogen into the iron ore bath from a hearth, or by using both methods (introducing hydrogen from above and below) to remove oxygen in the iron ore bath, and the iron ore is directly reduced without passing through a blast furnace or a steelmaking process to produce steel.SELECTED DRAWING: Figure 1

The invention relates to the technical field of iron and steel smelting, and provides a method and a system for preparing gas-based shaft furnace reducing gas from converter gas, the method comprises the following steps: respectively pretreating converter gas generated by a converter and top gas generated by a shaft furnace to recover waste heat in the gas and remove impurities in the gas; and introducing the pretreated converter gas, the pretreated top gas, carbon dioxide, oxygen and natural gas into a reforming furnace for catalytic reforming to generate reducing gas, and introducing the reducing gas into the shaft furnace for smelting the direct reduction iron. The method can solve the problem that the current converter gas resource recovery effect is relatively low, utilizes the sensible heat and reducing capacity of the converter gas, combines a catalytic reforming technology, catalyzes and reforms the converter gas, the top gas and other gases into the reducing gas, reduces the preparation cost of the gas-based shaft furnace reducing gas, and realizes efficient utilization of resources.

The application discloses a method for preparing direct reduced iron from iron-containing raw materials with near-zero carbon, and belongs to the technical field of steel metallurgy. The method comprises the following steps: uniformly mixing iron-containing raw materials, an organic-inorganic composite binder, biomass carbon and water, and then sequentially performing high-pressure forming and drying and solidification to obtain cold briquetting; and the cold briquetting is reduced by pure hydrogen to obtain direct reduced iron. The method can prepare cold briquetting suitable for the performance requirements of a shaft furnace for direct reduction at a relatively low temperature (<300 DEG C), and further prepares direct reduced iron by pure hydrogen reduction. The method has a short process flow, near-zero carbon emission, and provides a new technical route for the green and low-carbon transformation of the steel industry.

The present invention relates to a method for introducing carbon into direct reduced iron (DRI) (20), wherein at least one solid carbon support is added to the DRI (20), and the DRI (20) is hardened upon addition of the solid carbon support to the DRI (20).

The present invention provides a rotary kiln system and method for reducing iron oxide with hydrogen. The feed end and discharge end of the rotary kiln body are connected to the feed system and the discharge system, respectively. A waste heat recovery flue gas purification system and a preheating system are also provided between the discharge system and the feed system for heat recovery. The rotary kiln body is also connected to a hydrogen supply system and an electric heating system. The present invention adds equidistantly distributed air vents to the kiln body and adopts electric heating to inject hydrogen into the kiln body. The hydrogen injection causes the material to form a suspension, allowing a full chemical reaction between hydrogen and iron oxide. The temperature and hydrogen flow rate of the preheating zone and the metallizing zone are controlled in the direction of the rotary kiln body to realize the production process of reducing iron oxide with hydrogen. In the preheating zone, most of the iron oxide is reduced to ferrous oxide, and in the metallizing zone, the ferrous oxide is finally reduced to metallic iron. This achieves efficient reduction of iron and effectively improves the metallization rate of direct reduced iron.