scholarly journals Review and Thermodynamic Calculation of Gas-based Shaft Furnace Direct Reduction Ironmaking

2020 ◽  
Vol 218 ◽  
pp. 01032
Author(s):  
Weiming Luo
Keyword(s):  
Thermodynamic Calculation ◽  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reducing Agent ◽  
Reduction Degree

Different techniques have been used to study the reduction process of iron ore. In this paper, the reduction process of iron ore by CO at 200~1200°C is calculated. The effects of reducing agent overdose, reducing temperature and VCO2/(VCO+VCO2) on reducing degree were studied. The results show that the reduction degree increases with the increase of reducing agent and slows down gradually. During the reduction process, the reduction degree decreased significantly with the increase of VCO2/(VCO+VCO2). In this temperature segment, the reduction degree has a peak.

scholarly journals Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft Furnace

2018 ◽  
Author(s):  
Hamzeh Hamadeh ◽  
Olivier Mirgaux ◽  
Fabrice Patisson
Keyword(s):  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Central Zone ◽  
Reduction Process ◽  
Furnace Operation ◽  
Direct Reduction Of Iron ◽  
Energy And Momentum ◽  
Thermal Phenomena ◽  
Volume Method

This paper addresses the modeling of the iron ore direct reduction process in the context of the reduction in CO2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the lower one) to correctly describe the lateral gas feed and the cooling gas outlet. This model relies on a detailed description of the main physical-chemical and thermal phenomena using a multi-scale approach. The moving bed is assumed to be comprised of pellets of grains and crystallites. Eight heterogeneous and two homogeneous chemical reactions are taken into account. The local mass, energy and momentum balances are numerically solved using the finite volume method. This model was successfully validated by simulating the shaft furnaces of two direct reduction plants of different capacities. The calculated results reveal the detailed interior behavior of the shaft furnace operation. Eight different zones can be distinguished according to their predominant thermal and reaction characteristics. An important finding is the presence of a central zone of lesser temperature and conversion.

scholarly journals Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft Furnace

2018 ◽  
Author(s):  
Hamzeh Hamadeh ◽  
Olivier Mirgaux ◽  
Fabrice Patisson
Keyword(s):  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Central Zone ◽  
Reduction Process ◽  
Furnace Operation ◽  
Direct Reduction Of Iron ◽  
Energy And Momentum ◽  
Thermal Phenomena ◽  
Volume Method

This paper addresses the modeling of the iron ore direct reduction process, a process likely to reduce CO2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the lower one), to correctly describe the lateral gas feed and cooling gas outlet. This model relies on a detailed description of the main physical–chemical and thermal phenomena, using a multi-scale approach. The moving bed is assumed to be comprised of pellets of grains and crystallites. We also take into account eight heterogeneous and two homogeneous chemical reactions. The local mass, energy, and momentum balances are numerically solved, using the finite volume method. This model was successfully validated by simulating the shaft furnaces of two direct reduction plants of different capacities. The calculated results reveal the detailed interior behavior of the shaft furnace operation. Eight different zones can be distinguished, according to their predominant thermal and reaction characteristics. An important finding is the presence of a central zone of lesser temperature and conversion.

scholarly journals Detailed Modeling of the Direct Reduction of Iron Ore in a Shaft Furnace

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1865 ◽  
Author(s):  
Hamzeh Hamadeh ◽  
Olivier Mirgaux ◽  
Fabrice Patisson
Keyword(s):  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Central Zone ◽  
Reduction Process ◽  
Furnace Operation ◽  
Direct Reduction Of Iron ◽  
Energy And Momentum ◽  
Thermal Phenomena ◽  
Volume Method

This paper addresses the modeling of the iron ore direct reduction process, a process likely to reduce CO2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the lower one), to correctly describe the lateral gas feed and cooling gas outlet. This model relies on a detailed description of the main physical–chemical and thermal phenomena, using a multi-scale approach. The moving bed is assumed to be comprised of pellets of grains and crystallites. We also take into account eight heterogeneous and two homogeneous chemical reactions. The local mass, energy, and momentum balances are numerically solved, using the finite volume method. This model was successfully validated by simulating the shaft furnaces of two direct reduction plants of different capacities. The calculated results reveal the detailed interior behavior of the shaft furnace operation. Eight different zones can be distinguished, according to their predominant thermal and reaction characteristics. An important finding is the presence of a central zone of lesser temperature and conversion.

Thermodynamic study of reduction process of Bapy deposit iron ore concentrate by coal of Karazhyra deposit

2021 ◽  
Vol 77 (3) ◽  
pp. 262-271
Author(s):  
I. A. Rybenko ◽  
B. A. Edil’baev ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
E. V. Protopopov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Iron Ore ◽  
Iron Reduction ◽  
Direct Reduction ◽  
Reduction Process ◽  
Reducing Agent ◽  
Coal Consumption ◽  
Oxidative Potential ◽  
Reduction Of Iron ◽  
Iron Ore Concentrate

In modern ferrous metallurgy, direct reduction of iron from iron ore materials is becoming increasingly common. In order to assess the feasibility of using a particular technology, it is necessary to obtain information on the reduction processes of iron oxides. Taking into consideration that experimental research is usually expensive, a computational experiment is optimal, which allows to draw conclusions about the behavior of the studied objects on the basis of modeling high-temperature processes in complex thermodynamic systems with physicochemical transformations under equilibrium and non-equilibrium conditions. As a modeling tool, the Terra software complex created at the Moscow State Technical University named after N. E. Bauman was used. As a result of thermodynamic studies boundaries of redox processes are identified and optimal temperature and consumption of reducing agent were determined, which provide maximum degree of iron reduction. The results of simulation of iron reduction process from iron ore concentrate obtained during concentration of iron ore of Bapy deposit, by coal of Karazhyra deposit (Kazakhstan) are presented. Dependencies of composition and volume of gas phase, formed as a result of volatile coal components emission in the process of heating, degree of iron reduction at various coal consumption rates on the temperature was established. It was found that the complete reduction of iron occurs at a coal consumption of 25 kg/100 kg of concentrate and a temperature of 1013 K, and the further increase in the consumption of the reducing agent leads only to a change in the ratio of CO and SO2 in the gas phase towards a decrease in the oxidative potential and an increase in the temperature of completion of the reducing process.

Separation of aluminium and preparation of powdered DRI from lateritic iron ore based on direct reduction process

2016 ◽  
Vol 55 (3) ◽  
pp. 345-355 ◽  
Author(s):  
T. Jiang ◽  
L. Yang ◽  
G. Li ◽  
J. Luo ◽  
J. Zeng ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Process ◽  
Direct Reduction Process

scholarly journals Effect of Different Additives on Reaction Characteristics of Fluorapatite During Coal-Based Reduction of Iron Ore

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 923 ◽  
Author(s):  
Yongsheng Sun ◽  
Wentao Zhou ◽  
Yuexin Han ◽  
Yanjun Li
Keyword(s):  
Iron Ore ◽  
Contact Point ◽  
Energy Dispersive Spectrometer ◽  
Structural Evolution ◽  
Reduction Process ◽  
Reduction Degree ◽  
Reduction Temperature ◽  
Exponential Factor ◽  
Reduction Time ◽  
Effect Mechanism

In the coal-based reduction of high phosphorus oolitic hematite, it is particularly important to study the mechanism of phosphorus regulation during the formation of iron metals for the efficient development and utilization of iron ore. In this study, the thermodynamics of the coal-based reduction process of fluorapatite in different mineral systems, effect mechanism of the reduction degree, kinetics, mineral composition, and morphology of structural evolution samples were systematically investigated using FactSage software, single factor analysis, the isothermal method, X-ray diffraction (XRD), scanning electron microscope (SEM), and an energy dispersive spectrometer (EDS). Thermodynamic analysis indicates that the effect of the SiO2–Fe2O3–C system on reducing the initial reduction temperature of fluorapatite was stronger than that of the Al2O3–Fe2O3–C system. The effect mechanism of the reduction degree demonstrates that increasing the dosage of silica, iron oxide, carbon, reduction time, and reduction temperature could promote the reduction reaction of fluorapatite under certain conditions. Dynamics analysis shows that the best kinetic mechanism functions of the SiO2–Fe2O3–C system and the Al2O3–Fe2O3–C system were A1/3 = 1/3(1 − α)[−ln(1 − α)]−2 and A1/2 = 1/2(1 − α)[−ln(1 − α)]−1, respectively. The activation energy and pre-exponential factor of the reduction kinetics equation in the system containing silica were significantly lower than that in the system containing alumina, which explained that the catalytic effect of silica on the reduction of calcium fluorophosphate was far greater than that of alumina. XRD and SEM/EDS analysis indicate that the solid–solid reaction of alumina, silica, iron, and fluorapatite occurred during the reduction process, while calcium aluminate, calcium silicate, and calcium oxide were formed at the contact point. Among them, iron could absorb P2 gas so that it played a greater role in promoting the reduction of fluorapatite. Increasing the reduction temperature and prolonging the reduction time were beneficial to the reduction of fluorapatite.

scholarly journals Hydrogen Ironmaking: How It Works

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 922 ◽  
Author(s):  
Fabrice Patisson ◽  
Olivier Mirgaux
Keyword(s):  
Iron Ore ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Water Electrolysis ◽  
Current Standard ◽  
Ore Pellets ◽  
Production Of Hydrogen ◽  
Produce Steel ◽  
And Performance ◽  
Direct Reduction Of Iron

A new route for making steel from iron ore based on the use of hydrogen to reduce iron oxides is presented, detailed and analyzed. The main advantage of this steelmaking route is the dramatic reduction (90% off) in CO2 emissions compared to those of the current standard blast-furnace route. The first process of the route is the production of hydrogen by water electrolysis using CO2-lean electricity. The challenge is to achieve massive production of H2 in acceptable economic conditions. The second process is the direct reduction of iron ore in a shaft furnace operated with hydrogen only. The third process is the melting of the carbon-free direct reduced iron in an electric arc furnace to produce steel. From mathematical modeling of the direct reduction furnace, we show that complete metallization can be achieved in a reactor smaller than the current shaft furnaces that use syngas made from natural gas. The reduction processes at the scale of the ore pellets are described and modeled using a specific structural kinetic pellet model. Finally, the differences between the reduction by hydrogen and by carbon monoxide are discussed, from the grain scale to the reactor scale. Regarding the kinetics, reduction with hydrogen is definitely faster. Several research and development and innovation projects have very recently been launched that should confirm the viability and performance of this breakthrough and environmentally friendly ironmaking process.

The Effects of Reduction Parameter to Composite Pelet of Iron Ore and Coal Using Single Conveyor Belt Hearth Furnace

2016 ◽  
Vol 842 ◽  
pp. 115-119
Author(s):  
Johny Wahyuadi Soedarsono ◽  
Andi Rustandi ◽  
Yudha Pratesa ◽  
Rianti Dewi Sulamet-Ariobimo ◽  
Bagus Hadi Prabowo ◽  
...  
Keyword(s):  
Iron Ore ◽  
Direct Reduction ◽  
Reduction Process ◽  
Conveyor Belt ◽  
Separation Process ◽  
Iron Ores ◽  
Hearth Furnace ◽  
Composite Pellet ◽  
Direct Reduction Iron ◽  
Composite Pellets

Iron ores should be separated from oxygen and impurities which are coming along during the mining process. The separation process is known as reduction. There are two types of reduction process, and the most common is direct reduction process (DRP). There are several parameters in DRP which will determine the quantities of the product known as direct reduction iron (DRI). This worked discussed the effect of reduction temperature and pellet heap to the quantities of DRI using single conveyer belt Hearth furnace. The worked was done in laboratory scale using composite pellets with 14 mm in diameter. The ratio of iron ore to coal in the composite pellet is 1 to 1. The reduction process temperatures are 500oC, 700oC and 900oC. The reduction time is 25 minutes. While the pellets heap are also varied to 1, 3, 5, 7, 8 and 9 layers. The results show that DRI was formed in 700OC and the quantities of DRI are in line with the reduction temperatures and layers of composite pellets heap.

Fundamental Study on Application of Gas-Based Shaft Furnace Direct Reduction Process to High Efficiency and Clean Utilization of Paigeite

2011 ◽  
Vol 233-235 ◽  
pp. 753-758
Author(s):  
Zhao Cai Wang ◽  
Man Sheng Chu ◽  
Zhuang Nian Li ◽  
Jue Tang ◽  
Qing Jie Zhao ◽  
...  
Keyword(s):  
Electric Furnace ◽  
Shaft Furnace ◽  
Direct Reduction ◽  
Reduction Process ◽  
Technical Problems ◽  
Direct Reduction Process ◽  
Comprehensive Utilization ◽  
Iron Concentrate ◽  
New Process ◽  
Reduction Swelling

The paigeite resources are abundant in China, but most of them are difficult to be utilized efficiently because of the current technical problems on industrial practice. It is necessary to perfected and innovated for comprehensive utilization of paigeite. The new process of gas-based shaft furnace direct reduction-electric furnace smelting separation provides a new way to efficient and clean comprehensive utilization of paigeite resources. In this paper, the pellets are prepared from boron-bearing iron concentrate. The mechanisms of roasting, the rules of reduction, and the properties of reduction swelling are also investigated. And then the pellets after reduction are smelted and separated in electric furnace to study the properties of products and analyze the feasibility and superiority of new technique. The results showed that boron-bearing iron concentrate is a kind of good raw material for pelletizing process. The properties of boron-bearing pellets after roasting for 20 min at 1200°C could meet to the requirements of gas-based shaft furnace direct reduction process, which exhibited fast reaction rate, good reduction swelling properties and high compressive strength both before and after reduction. With the new process, the efficient separation of boron and iron can be realized. The high boron grade and high activity of boron-rich slag obtained from new process can be used directly in boric acid manufacture. The new process shows excellent tech-economy feasibility to achieve efficiency and clean comprehensive utilization of paigeite resources.

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