Circulation and Reduction Behavior of Iron Ore in A Circulating Fluidized Bed.

Itaya, Hiroshi; Sato, Masahiko; Taguchi, Sachihiro

doi:10.2355/isijinternational.34.393

Cited by 9 publications

(13 citation statements)

References 0 publications

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“…In contrast to the common belief that the total iron content of the chemical analysis is the main quality parameter for iron ores, this work shows that the petrographic structure of the iron oxide and the structure of the metallic iron have even more influence on reducibility. The main findings concerning the reduction of different iron ore blends (magnetitic, limonitic, and hematitic) under similar reduction conditions have also been verified by trends and morphological images from the literature data …”

Section: Introductionsupporting

confidence: 65%

“…Former research was mainly focused on the influence of process conditions on the materials performance during fluidized bed reduction. By the change of temperature, gas flow rate and gas oxidation degree (GOD) iron ore usually shows differences in reduction behavior . For instance, a higher temperature (temperature range 700–950 °C) or partial pressure of H 2 + CO leads to higher reducibility and higher reduction degrees (RDs).…”

Section: Introductionmentioning

confidence: 99%

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Reduction Behavior and Structural Evolution of Iron Ores in Fluidized Bed Technologies—Part 2: Characterization and Evaluation of Worldwide Traded Fine Iron Ore Brands

Pichler

Mali

Plaul

et al. 2015

steel research int.

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The reduction of iron ore fines by means of fluidized bed technology has become an alternative route of ironmaking. To investigate the reduction behavior of fine ores and to improve fluidized bed processes, a lab scale fluidized bed facility is installed. The reactor is charged with different kinds of fine ores. The reactors get fluidized by a reducing gas mixture containing H2, H2O, CO, CO2, CH4, and N2 in variable range. Additionally, a sampling system is installed, which enables the sampling of bed material during reduction. All samples are analyzed regarding their grain size distribution, chemistry, and morphology. The comparison of the raw input ore with the reduced ore—bed samples during the tests and final material—leads to a new way of fine ore characterization. After the determination of a standardized process, globally traded iron ore fines are tested under the same process conditions. The results enable the validation of the morphological evolution of different iron ore types and brands (hematitic, magnetitic, and limonitic) during the reduction with CO‐rich reducing gas in fluidized bed processes. Further investigation on the structure and porosity of the different phases is done to evaluate the relation to reduction rate and final reduction degree.

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Section: Introductionsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Reduction Behavior and Structural Evolution of Iron Ores in Fluidized Bed Technologies—Part 2: Characterization and Evaluation of Worldwide Traded Fine Iron Ore Brands

Pichler

Mali

Plaul

et al. 2015

steel research int.

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“…The Ea of each step from both macrokinetics and microkinetics have been calculated by many investigators. [21][22][23][24][25] The typical ranges of Ea of different rate controlling steps have been summarized by Strangway.…”

Section: Reduction Mechanismmentioning

confidence: 99%

Reduction Kinetics of Fine Hematite Ore Particles with a High Temperature Drop Tube Furnace

et al. 2015

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HIsarna is a new coal based smelting reduction process, which has the excellent features of using coal and fine hematite ore directly as raw materials instead of coke and pellet. In this context, the reduction kinetics of hematite ore fines in the smelting cyclone was studied in the laboratory scale. The gas-solid and gas-molten particle reduction behaviour were studied with a High-temperature Drop Tube Furnace (HDTF) and a combination of various characterization methods was used to track the kinetic behaviour such as chemical titration, optical microscope and Scanning Electron Microscope (SEM). A series of experiments with different reaction time (210-2 020 ms) has been conducted at different temperatures from 1 550 K to 1 750 K, thus enabling the kinetic study of the partially reduced hematite ore particles. It was found that a quantity of micro pores was formed during the reduction process mainly due to the loss of oxygen. The un-reacted shrinking core model could be used to describe both gas-solid particle reaction and gas-molten particle reaction.

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“…The equilibrium concentrations of H 2 and CO ðp Ã H 2 and p Ã CO Þ are dependent on temperature and were calculated from the thermodynamic data of involved reactants polynomial fitted to the data taken from the literature. [23] To take the different reduction potentials of H 2 and CO into account, the reduction of iron ore with two gas components (H 2 ,CO) is described as a parallel reaction. In this example, it is only focused on the forward reactions.…”

Section: Reduction Kineticsmentioning

confidence: 99%

“…To investigate the kinetics of the iron ore reduction, different kinetics approaches from the literature were studied [16][17][18][19][20][21][22][23][24] and tests at different operating conditions were carried out in a batch reactor. [6] It was also shown from batch experiments in the laboratory-scale reactor that the reduction can be divided into three phases of different kinetics depending on Y (refer to Figure 3).…”

Section: Reduction Kineticsmentioning

confidence: 99%

Iron ore reduction in a continuously operated multistage lab-scale fluidized bed reactor—Mathematical modeling and experimental results

Thurnhofer

Schuster

Löffler

et al. 2006

Metall Mater Trans B

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Industrial-scale fluidized bed processes for iron ore reduction (e.g., FIOR and FINMET) are operated by continuous feeding of ore, while laboratory tests are mostly performed under batchwise operation. The reduction behavior under continuous operation is influenced by both the residence time of the iron ore particles and the reduction kinetics, which is obtained by batch tests. In a mathematical model for such a process, the effect of both phenomena has to be considered. The residence time distribution of iron ore particles in a laboratory fluidized bed reactor was obtained by measuring the response of a step input and described by mathematical models similar to a continuously stirred tank reactor. In the same reactor, reduction tests with continuous feeding of iron ore were performed. Based on batch tests in a fluidized bed reactor, a mathematical model was developed to describe the kinetics of iron ore reduction under fluidized bed conditions. This kinetic model was combined with the fluidized bed reactor model to describe continuous iron ore reduction. In this detailed model, the change of gas composition while rising in the fluidized bed was considered. The degree of reduction and the gas conversion for reactors in series were calculated. The results obtained by the mathematical model were compared with experimental data from the laboratoryscale reactor.

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Circulation and Reduction Behavior of Iron Ore in A Circulating Fluidized Bed.

Cited by 9 publications

References 0 publications

Reduction Behavior and Structural Evolution of Iron Ores in Fluidized Bed Technologies—Part 2: Characterization and Evaluation of Worldwide Traded Fine Iron Ore Brands

Reduction Behavior and Structural Evolution of Iron Ores in Fluidized Bed Technologies—Part 2: Characterization and Evaluation of Worldwide Traded Fine Iron Ore Brands

Reduction Kinetics of Fine Hematite Ore Particles with a High Temperature Drop Tube Furnace

Iron ore reduction in a continuously operated multistage lab-scale fluidized bed reactor—Mathematical modeling and experimental results

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