Kinetics of the low-temperature hydrogen reduction of magnetite concentrates

Teplov, O. A.

doi:10.1134/s0036029512010132

Cited by 27 publications

(21 citation statements)

References 10 publications

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“…Influence of particle size on the reduction rate of magnetite concentrate with hydrogen at 400 C. Reproduced with permission. [35] Copyright 2012 by Pleiades Publishing, Ltd. The criteria for ordering include the specific surface area of the iron ores.…”

Section: Effect Of Iron Oxide Mineralogy On the Reduction Ratementioning

confidence: 99%

Reduction of Iron Oxides with Hydrogen—A Review

Spreitzer

Schenk

2019

steel research int.

383

161

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This review focuses on the reduction of iron oxides using hydrogen as a reducing agent. Due to increasing requirements from environmental issues, a change of process concepts in the iron and steel industry is necessary within the next few years. Currently, crude steel production is mainly based on fossil fuels, and emitting of the climate‐relevant gas carbon dioxide is integral. One opportunity to avoid or reduce greenhouse gas emissions is substituting hydrogen for carbon as an energy source and reducing agent. Hydrogen, produced via renewable energies, allows carbon‐free reduction and avoids forming harmful greenhouse gases during the reduction process. The thermodynamic and kinetic behaviors of reduction with hydrogen are summarized and discussed in this review. The effects of influencing parameters, such as temperature, type of iron oxide, grain size, etc. are shown and compared with the reduction behavior of iron oxides with carbon monoxide. Different methods to describe the kinetics of the reduction progress and the role of the apparent activation energy are shown and proofed regarding their plausibility.

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Section: Effect Of Iron Oxide Mineralogy On the Reduction Ratementioning

confidence: 99%

Reduction of Iron Oxides with Hydrogen—A Review

Spreitzer

Schenk

2019

steel research int.

383

161

View full text Add to dashboard Cite

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“…The size and geometry of the pellets and temperature of the inlet gas have a strong influence on the reaction rate. The reaction rate varies inversely with the size of the pellets [53]. The reaction rate is faster with hematite ore than magnetite ore as the porosity of intermediate reaction products formed by hematite is higher [54].…”

Section: Hydrogen Direct Reduction Of Iron Orementioning

confidence: 99%

Decarbonization of the Iron and Steel Industry with Direct Reduction of Iron Ore with Green Hydrogen

2020

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Production of iron and steel releases seven percent of the global greenhouse gas (GHG) emissions. Incremental changes in present primary steel production technologies would not be sufficient to meet the emission reduction targets. Replacing coke, used in the blast furnaces as a reducing agent, with hydrogen produced from water electrolysis has the potential to reduce emissions from iron and steel production substantially. Mass and energy flow model based on an open-source software (Python) has been developed in this work to explore the feasibility of using hydrogen direct reduction of iron ore (HDRI) coupled with electric arc furnace (EAF) for carbon-free steel production. Modeling results show that HDRI-EAF technology could reduce specific emissions from steel production in the EU by more than 35%, at present grid emission levels (295 kgCO 2 /MWh). The energy consumption for 1 ton of liquid steel (tls) production through the HDRI-EAF route was found to be 3.72 MWh, which is slightly more than the 3.48 MWh required for steel production through the blast furnace (BF) basic oxygen furnace route (BOF). Pellet making and steel finishing processes have not been considered. Sensitivity analysis revealed that electrolyzer efficiency is the most important factor affecting the system energy consumption, while the grid emission factor is strongly correlated with the overall system emissions.Energies 2020, 13, 758 2 of 23 country, on the other hand, has a per capita steel consumption of 66.3 kg. As the standard of living in developing countries increases, demand for steel will grow further. The demand for steel will increase until 2050 [4]. Steel could be produced by reducing iron ore or by recycling steel scrap in an electric arc furnace (EAF). Iron and steel sector releases seven percent of the total CO 2 emission and 16% of the total industrial emission of CO 2 globally [5,6]. Limited availability of scrap and demand for special grades of steel, which can not be produced from steel recycling, would lead to an increased demand for ore based steel production in the future. More than 80% [3] of the ore based steel is produced through the BF-BOF route. The BF-BOF route uses approximately 18 GJ/t of energy supplied from coal [7], and has an emission intensity of approximately 1870 kgCO 2 /tls [4,8] (considering pellet making, steel rolling and finishing steps). Majority of the emissions is released from the blast furnace (61%) and coke making plant (27%) [9].Some of the alternative processes with significantly reduced carbon footprint are BF-BOF with carbon capture and storage (CCS), direct reduction of iron ore (DRI) with CCS, electrowining (electrolysis of iron ore) [10] and green hydrogen-based DRI production. Integration of CCS in steelmaking processes is being explored under the ultra-Low carbon dioxide(CO 2 ) steelmaking (ULCOS) [11,12] project. However, concerns over the safe transport and storage of captured makes CCS options less attractive. Electrowining or molten electrolysis of iron ore is a relatively new technol...

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“…The relationship among k(T), temperature T and apparent activation energy E a is given by the Arrhenius equation, Eq. [14]. A denotes the pre-exponential factor, and R represents the gas constant.…”

Section: B Determination Of Apparent Activation Energy Using the Modmentioning

confidence: 99%

“…To determine the apparent activation energy, a combination of Eqs. [12] and [14] is required, which results in Eq. [15].…”

Section: B Determination Of Apparent Activation Energy Using the Modmentioning

confidence: 99%

“…[9,10] Investigations regarding the reduction kinetics of iron oxides using hydrogen as a reducing agent have been carried out by many authors. [11][12][13][14][15][16][17][18][19] The scope of this work was to investigate the reduction kinetics of iron ore fines during fluidized bed reduction using hydrogen as a reducing agent in a suitable temperature range for an industrial application. The determination of the apparent activation energy against the degree of reduction, model-fitting analysis of experimental results as well as multistep kinetic analysis were carried out.…”

Section: Introductionmentioning

confidence: 99%

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Iron Ore Reduction by Hydrogen Using a Laboratory Scale Fluidized Bed Reactor: Kinetic Investigation—Experimental Setup and Method for Determination

Spreitzer

Schenk

2019

Metall Mater Trans B

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The reduction kinetics of hematite iron ore fines to metallic iron by hydrogen using a laboratory fluidized bed reactor were investigated in a temperature range between 873 K and 1073 K, by measuring the weight change of the sample portion during reduction. The fluidization conditions were checked regarding plausibility within the Grace diagram and the measured pressure drop across the material during experiments. The apparent activation energy of the reduction was determined against the degree of reduction and varied along an estimated twopeak curve between 11 and 55 kJ mol À1 . Conventional kinetic analysis for the reduction of FeO to metallic iron, using typical models to describe gas-solid reactions, does not show results with high accuracy. Multistep kinetic analysis, using the Johnson-Mehl-Avrami model, shows that the initial stage of reduction from Fe 2 O 3 to Fe 3 O 4 , and partly to FeO, is controlled by diffusion and chemical reaction, depending on the temperature. Further reduction can be described by a combination of nucleation and chemical reaction, whereby the influence of nucleation increases with an increasing reduction temperature. The results of the kinetical analysis were linked to the shape of the curve from apparent activation energy against the degree of reduction.

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Kinetics of the low-temperature hydrogen reduction of magnetite concentrates

Cited by 27 publications

References 10 publications

Reduction of Iron Oxides with Hydrogen—A Review

Reduction of Iron Oxides with Hydrogen—A Review

Decarbonization of the Iron and Steel Industry with Direct Reduction of Iron Ore with Green Hydrogen

Iron Ore Reduction by Hydrogen Using a Laboratory Scale Fluidized Bed Reactor: Kinetic Investigation—Experimental Setup and Method for Determination

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