Results of Hydrogen Reduction of Iron Ore Pellets at Different Temperatures

Kovtun, Oleksandr; Levchenko, Mykyta; Ilatovskaia, Mariia O.; Aneziris, Christos G.; Volkova, Olena

doi:10.1002/srin.202300707

Cited by 5 publications

(2 citation statements)

References 38 publications

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“…Initially, fine micropores and dense metallized iron formations were seen at 700 • C and 800 • C, with larger micropores at 800 • C. Macropores were absent at these lower temperatures, but appeared at 900 • C and 1000 • C, suggesting enhanced hydrogen diffusivity and increased reduction rates. Surface cracks at 1000 • C also indicated high hydrogen diffusivity and effective reduction [103].…”

Section: Results Of Research Studies Focused On the Reduction In Iron...mentioning

confidence: 98%

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

Miškovičová,

Legemza,

Demeter

et al. 2024

Metals

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This paper focuses on the study of current knowledge regarding the use of hydrogen as a reducing agent in the metallurgical processes of iron and steel production. This focus is driven by the need to introduce environmentally suitable energy sources and reducing agents in this sector. This theoretical study primarily examines laboratory research on the reduction of Fe-based, metal-bearing materials. The article presents a critical analysis of the reduction in iron oxides using hydrogen, highlighting the advantages and disadvantages of this method. Most experimental facilities worldwide employ their unique original methodologies, with techniques based on Thermogravimetric analysis (TGA) devices, fluidized beds, and reduction retorts being the most common. The analysis indicates that the mineralogical composition of the Fe ores used plays a crucial role in hydrogen reduction. Temperatures during hydrogen reduction typically range from 500 to 900 °C. The reaction rate and degree of reduction increase with higher temperatures, with the transformation of wüstite to iron being the slowest step. Furthermore, the analysis demonstrates that reduction of iron ore with hydrogen occurs more intensively and quickly than with carbon monoxide (CO) or a hydrogen/carbon monoxide (H2/CO) mixture in the temperature range of 500 °C to 900 °C. The study establishes that hydrogen is a superior reducing agent for iron oxides, offering rapid reduction kinetics and a higher degree of reduction compared to traditional carbon-based methods across a broad temperature range. These findings underscore hydrogen’s potential to significantly reduce greenhouse gas emissions in the steel production industry, supporting a shift towards more sustainable manufacturing practices. However, the implementation of hydrogen as a primary reducing agent in industrial settings is constrained by current technological limitations and the need for substantial infrastructural developments to support large-scale hydrogen production and utilization.

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Section: Results Of Research Studies Focused On the Reduction In Iron...mentioning

confidence: 98%

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

Miškovičová,

Legemza,

Demeter

et al. 2024

Metals

View full text Add to dashboard Cite

show abstract

“…Additionally, the size of the reduction is another significant factor in diffusion resistance, where it is evident that larger pellets necessitate more time for reduction. It has been demonstrated by Kovtun et al [120] that higher temperatures correspond to increased pore size and overall porosity. Also, Sadeghi et al [121] demonstrated that an increase in pore complexity and tortuosity is led by higher porosity evolution rates at higher temperatures and in larger pellets.…”

Section: Solid Specsmentioning

confidence: 91%

Modeling of Gaseous Reduction of Iron Oxide Pellets Using Machine Learning Algorithms, Explainable Artificial Intelligence, and Hyperparameter Optimization Techniques

Hosseinzadeh,

Kasiri,

Rezaei

2024

steel research int.

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In this study, a novel application of machine learning (ML) is introduced to pellet modeling in the intricate non‐catalytic gas–solid reaction of direct reduction of iron oxide in the steel industry. Twenty ML models are developed using four algorithms: multilayer perceptron neural networks (MLPNN), radial basis function neural network (RBFNN), support vector regression, and random forest (RF). Hyperparameter optimization is conducted using Bayesian algorithms, random search, and grid search. The optimum model achieves a mean squared error test of 0.0052 with random RF for the larger dataset (872 samples), while smaller datasets (132, 225, and 242 samples) produce optimum models with MLPNN and RBFNN. Hyperparameters vary between the larger datasets and the smaller datasets. The models offer insight into the complex interactions among variables, including time, temperature, gas composition, hematite composition, pellet radius, and initial pellet porosity, influencing the metallization degree. In this study, the significant role of time and temperature is emphasized, as revealed by explainable artificial intelligence using Shapley additive explanation analysis that utilizes the game theory, and the effects of pellet modeling parameters are elucidated through 3D plots, particularly highlighting the impact of changing H2/CO proportion on metallization degree and carbon deposit.

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Effect of SiO₂ and Al₂O₃ on the Thermophysical Properties and the Foaming Index of Electric Arc Furnace Slag from the Production of Construction Steel

Levchenko,

Kovtun,

Angelini

et al. 2024

steel research int.

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Viscosity, density, and surface tension of an industrial electric arc furnace (EAF) slag from production of construction steel with varying SiO2 and Al2O3 contents are investigated using a rotating viscometer and the maximum bubble pressure method. In addition, influence of thermophysical properties on foaming index is discussed. To predict the behavior of the solid phase in the slag at different temperatures, thermodynamic calculations are performed using FactSage 8.1 software. The experiments demonstratethat SiO2 and Al2O3 act as network formers in the studied slag systems, resulting in increased viscosity values in the liquid‐dominant region and decreased density of the slag. The presence of alumina and silica altered the behavior of the slag in the liquid‐dominant region, shifting the breaking point of the slags. Furthermore, the addition of silica decreases the surface tension of the slag, confirming its role as a surfactant. However, the addition of Al2O3 increases the surface tension due to the high surface tension of pure alumina. Consequently, the foaming index of the slag can increase by ≈40%, primarily due to the polymerization of the slag.

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Results of Hydrogen Reduction of Iron Ore Pellets at Different Temperatures

Cited by 5 publications

References 38 publications

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

Modeling of Gaseous Reduction of Iron Oxide Pellets Using Machine Learning Algorithms, Explainable Artificial Intelligence, and Hyperparameter Optimization Techniques

Effect of SiO₂ and Al₂O₃ on the Thermophysical Properties and the Foaming Index of Electric Arc Furnace Slag from the Production of Construction Steel

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Results of Hydrogen Reduction of Iron Ore Pellets at Different Temperatures

Cited by 5 publications

References 38 publications

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

An Overview Analysis of Current Research Status in Iron Oxides Reduction by Hydrogen

Modeling of Gaseous Reduction of Iron Oxide Pellets Using Machine Learning Algorithms, Explainable Artificial Intelligence, and Hyperparameter Optimization Techniques

Effect of SiO2 and Al2O3 on the Thermophysical Properties and the Foaming Index of Electric Arc Furnace Slag from the Production of Construction Steel

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Product

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Effect of SiO₂ and Al₂O₃ on the Thermophysical Properties and the Foaming Index of Electric Arc Furnace Slag from the Production of Construction Steel