129 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.

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 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.

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.

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 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).

This invention proposes a method for introducing reducing hydrogen into a vertical shaft furnace for pure hydrogen reduction. The furnace comprises, from top to bottom, a preheating reduction zone, a high-temperature reduction zone, a constant pressure zone, and a cooling zone. The method includes: introducing preheated hydrogen into the preheating reduction zone to preheat the furnace charge; introducing a first high-temperature reducing hydrogen and a second high-temperature reducing hydrogen into the upper middle and lower parts of the high-temperature reduction zone, respectively, to reduce the furnace charge; and introducing cooling hydrogen into the cooling zone to cool the direct reduced iron generated during reduction. This invention solves the technical problems of high difficulty in temperature control and reduction reaction control in existing pure hydrogen vertical shaft furnaces. By introducing different types of reducing hydrogen into different areas of the furnace, the heat exchange and reduction reaction process can be controlled, thereby improving the metal reduction rate and reaction efficiency of the furnace.

The invention discloses a device and a method for producing direct reduced iron by full hydrogen, circulating hydrogen discharged from a reduction furnace enters a hydrogen circulating system and directly exchanges heat with high-temperature coke produced by a coke oven in a coking process after being cooled and dehydrated, and the high-temperature circulating hydrogen after heat exchange carries coke powder; the high-temperature circulating hydrogen enters a reduction area of the reduction furnace to participate in reduction of iron-containing materials after being subjected to gravity settling and cyclone dust removal for coke powder removal, and sponge iron is obtained; coke powder obtained after cyclone dust removal enters a gasification furnace of a carburizing system to be oxidized into CO, and then the CO serves as carburizing gas to enter a carburizing area of a reduction furnace to complete carburizing of sponge iron. According to the invention, a coking process and a full-hydrogen direct reduction iron production process are coupled, so that the heating of circulating reducing gas and the carburization of direct reduction iron are realized.

Disclosed is a technique by which hot direct reduced iron having a heightened carbon concentration is produced through a direct reduction process.　This method for producing hot direct reduced iron comprises: a reduction step in which a reducing gas is brought into contact with an iron oxide feedstock to obtain iron metal; and a cooling step in which the iron metal is carbonized while being cooled, thereby obtaining hot direct reduced iron. The cooling step comprises a first step, in which after the reduction step, methane gas is brought into contact with the iron metal, and a second step, in which after the first step, CO gas is brought into contact with the iron metal. In the second step, the iron metal in contact with the CO gas has a temperature of 400-700°C. In the second step, the proportion of the volume of a discharge gas that is discharged from the system to the volume of the gas that is supplied is 40% or higher.

The invention relates to a low-carbon direct reduction iron rotary kiln which adopts electric heating and utilizes a carbon-containing reducing agent to reduce iron ore. Two ends of a rotary pipe of the rotary kiln are provided with dynamic seals for hermetically connecting a rotating part and a fixed part of the rotary kiln. The dynamic seal is composed of more than two groups of annular seals and annular air gaps which are arranged between the annular seals and divide the annular seals into groups, the air gaps are provided with air inlet holes, CO2 is connected into the air inlet holes, and the air pressure in the air gaps is kept to be larger than the ambient atmospheric pressure and the atmosphere pressure in a hearth of the rotary kiln. More than two feeding bins and more than two discharging bins are arranged, and CO2 is used as purging gas, so that air is completely isolated from being mixed in the feeding and discharging processes, and the air is prevented from entering a hearth atmosphere system of the rotary kiln. The method has the advantages that CO2 generated in the reduction process is utilized, equipment is simple and reliable, air isolation is thorough, and cost is low.

The present application relates to the technical field of pneumatic conveying, in particular to a hot direct reduction iron material pneumatic conveying method and system. The conventional gas pipeline conveying method is used to convey the HRDI material into the electric arc furnace by pneumatic conveying, and the equipment is prone to wear and breakage. In view of the above problems, the present application provides a hot direct reduction iron material pneumatic conveying method. The axis of the bottom three inclined pipe elbow sections of the plug sender structure is designed to form an angle of not more than 20° with the axis of the straight pipe section in the opposite direction of the material conveying, and the combined action of the pulse gas source valve group and the plug gas source valve group forms discontinuous material plugs in the conveying pipeline, which significantly reduces the abrasion of the conveying pipeline inner wall caused by the material in the pneumatic conveying process, and the blocking and crushing phenomenon of the hot direct reduction iron material in the conveying pipeline.

A direct reduction apparatus for the direct reduction of iron oxides includes a gas circulation loop comprising: - a reactor (1) having a reduction zone (2) suitable for loading the iron oxides; - an external source (20) for supplemental gas; - a recovery and treatment pipeline (10) arranged downstream of the reactor (1) for recovering and treating waste gas discharged from the reactor (1); - A treatment and feed line (11) arranged upstream of the reactor (1) is used to treat the process gas obtained by mixing the supplementary gas with the waste gas treated in the recovery and treatment line (10) and to supply the process gas to the reduction zone (2) of the reactor (1); wherein the recovery and treatment line (10) is connected downstream to the treatment and feed line (11); wherein, in its end extension near the end of the treatment and feed line (11), the recovery and treatment line (10) includes a carbon dioxide removal device (50) to remove carbon dioxide from the waste gas, the carbon dioxide removal device being arranged upstream of a compressor (42) for compressing the waste gas and sending it to the treatment and feed line (11).

The present invention relates to the technical field of ferrous metallurgy, and relates to a process and system for recycling a pneumatic conveying gas for hot direct reduced iron. The process comprises the following steps: storing, in a material tank, hot direct reduced iron from a hot direct reduced iron pneumatic conveying pipe connected to the material tank, discharging dust-containing high-temperature raw conveying gas from the material tank, recovering waste heat by means of an indirect waste heat recovery device, performing dust removal and purification by a dry dust removal device to form purified conveying gas, and then reusing the purified conveying gas to the hot direct reduced iron pneumatic conveying pipe. In the present invention, the indirect waste heat recovery device is used to recover sensible heat of the dust-containing high-temperature raw conveying gas, and then produce steam as a byproduct, thereby realizing waste heat recovery; iron-containing dust in the dust-containing high-temperature raw conveying gas recovered by the dry dust removal device is directly used by a steelmaking user or transported outwards, improving utilization of raw materials, and saving the raw materials; and a wastewater- and sludge-free treatment system is realized by means of an indirect waste heat recovery process and a dry dust removal process.

A method and system for producing a direct reduced iron product, including: producing hot direct reduced iron in a shaft furnace; receiving the hot direct reduced iron in a feed leg downstream of the shaft furnace; and adding carbon to the hot direct reduced iron in the feed leg downstream of the shaft furnace to form a direct reduced iron product. The method can also include receiving the hot direct reduced iron to which carbon has been added and briquetting it to form a direct reduced iron product. The method can also include receiving hot direct reduced iron in an additional (optionally parallel) feed leg downstream of the shaft furnace, and adding additional carbon (in different amounts) to the hot direct reduced iron in the additional feed leg, thereby utilizing the same hot direct reduced iron stream to form additional direct reduced iron products having different carbon contents.

compacted 'green' briquettes between 5 cm 3 and 20 cm 3 in size comprising a composition comprising at least 30% lignocellulosic biomass material by dry weight and at least 55% iron ore fines by weight, a density between 1.4 g / cm 3 and 2.0 g / cm 3 and a compacted strength of at least 500 N. Direct reduced iron briquettes suitable for producing iron and / or steel comprise at least 85% iron by weight and at least 1% fixed carbon by weight and a volume between 7.5 cm 3 and 30 cm 3 in size, wherein said briquettes have the above composition prior to reduction (i.e. as 'green' briquettes).

The present application relates to the technical field of the comprehensive utilization of resources, and in particular to a comprehensive utilization method for iron ore. The comprehensive utilization method for iron ore comprises the following steps: S1. preparing iron ore into pellets and performing a reduction reaction on the pellets to obtain direct reduced iron; S2. smelting the direct reduced iron to obtain molten slag and molten iron, wherein the content of ferrous oxide in the molten slag is 1 wt% to 4 wt%; and S3. directly hot preparing rock wool from the molten slag online. Different from the prior art, the present application involves the addition of a carbonaceous reducing agent during smelting, reducing the content of ferrous oxide in the obtained molten slag, and improving the thermal insulation performance and tensile mechanical performance of the prepared rock wool, thereby improving the energy-saving effect, durability and safety of the rock wool while increasing the yield of obtained metals, increasing the yield of molten iron, and improving economic benefits.

The invention discloses a method for preparing low-nitrogen pure molten iron through efficient desulfurization and dephosphorization of directly reduced pellets, and relates to the technical field of direct reduction iron refining and electric induction furnace metallurgy. Comprising a high-alkalinity desulfurization refining stage and a high-oxidability dephosphorization refining stage, wherein in the high-alkalinity desulfurization refining stage, a high-alkalinity desulfurization refining agent CaO-Al2O3-MgO-CaF2 with CaO as a main component is added into molten direct reduction iron molten iron after melting; a high-oxidability dephosphorization refining stage: after the desulfurization refining is completed, adding a CaO-Fe2O3 / FeO-Na2O-MgO-SiO2 series high-oxidability dephosphorization refining agent taking Fe2O3 / FeO as a main component into the molten iron, and blowing air or oxygen into the molten iron in an initial stage of refining, so that the molten steel is subjected to a high-oxidation potential dephosphorization reaction under a low-sulfur background; through continuous cooperation of the two stages, the two impurities of sulfur and phosphorus are efficiently and deeply removed.

This application relates to a method, apparatus, and electronic equipment for assessing the demand response potential of a zero-carbon hydrogen metallurgical system. The method includes: constructing an operating model of a hydrogen-based shaft furnace considering the metallization rate of direct reduced iron; establishing an objective function based on the production baseline load of the zero-carbon hydrogen metallurgical system; constructing a demand response potential assessment model for the zero-carbon hydrogen metallurgical system based on the objective function, constraints of the electrolyzer in the zero-carbon hydrogen metallurgical system, and constraints of the operating model of the hydrogen-based shaft furnace; determining the demand response potential assessment index for the zero-carbon hydrogen metallurgical system; and assessing the demand response potential of the zero-carbon hydrogen metallurgical system under real-time electricity pricing based on the assessment model and the assessment index. This solves the problems in related technologies, such as the lack of assessment of the flexibility of the zero-carbon hydrogen metallurgical system and the limited utilization of flexibility resources, leading to severe wind and solar power curtailment, grid backflow, and voltage exceedances, resulting in high production costs.

A direct reduction method to manufacture a direct reduced iron product 12 having a carbon content less than 1.8% by weight and a shaft furnace exit temperature lower than 65° C. A carbon-containing cooling gas 30 is introduced into the cooling zone 3 of the shaft furnace 1 with a flow rate higher than 800 Nm3 / ton of Direct Reduced Iron produced.

The present invention relates to a furnace having an inner surface (2) comprising copper. The inner surface (2) comprises at least one steel insert (1), the at least one steel insert (1) creating a protrusion extending from the inner surface (2). The present invention also relates to a cooling element (17) for a furnace comprising at least one steel insert (1) creating a protrusion extending from the cooling element (17). The present invention also relates to a method for generating an autogenous protective layer on the inner surface (2) of a furnace and to the use of the furnace in a direct iron reduction process, electric smelting process, electric reduction process, flash smelting process, flash converting process, bath smelting process or bath converting process.