Kinetics of reduction of ferrous oxide with hydrogen in a fluidized bed at steady state

Feinman, Jerome; Drexler, Thomas D.

doi:10.1002/aic.690070411

Cited by 18 publications

(11 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For better understanding of the reduction process of individual iron ore particles, the laboratory studies were conducted by using two kinds of reactors: fluidized bed and gas conveyed system. The intensive laboratory investigations [9][10][11][12][13] on the fluidized bed reduction of iron ore fines started in the 1960's for the alternative ironmaking processes based on fluidized bed reactors: direct reduction processes 14,15) (e.g. FIOR, FINMET and Circored) and the pre-reduction stage in the smelting reduction processes 16,17) (e.g.…”

Section: Introductionmentioning

confidence: 99%

Melting and Reduction Behaviour of Individual Fine Hematite Ore Particles

Yang

Zou

et al. 2015

ISIJ International

View full text Add to dashboard Cite

HIsarna is a new alternative ironmaking process of ULCOS program, which is under intensive development at EU. It uses coal and fine iron ore directly as raw materials instead of coke and pellet. In this context, the melting and pre-reduction behaviour of hematite ore in the smelting cyclone of HIsarna process was studied in the laboratory scale. The experimental study which used the typical reaction conditions of smelting cyclone in the pilot plant supplies a good reference to the HIsarna process and the results are helpful on determining the temperature range, gas composition and particle size in the smelting cyclone. All the experiments were performed in a High-temperature Drop Tube Furnace. The experimental temperature was varied from 1 550 K to1 750 K. A series of experiments have been conducted with different reaction time which was varied from 210 ms to 2 020 ms, thus enabling the characterization of partially reduced samples. It was found that the reduction degree increases with the increase of temperature and residence time, while decreases with the increase of particle size. The maximum reduction degree at the studied conditions is approximately in the range of 23-30%. Both solid sample and molten sample were obtained at the current experimental conditions. The completely gas-solid particle reduction took place at 1 550 K, 1 600 K for the residence time up to 2 020 ms. Fully molten particles can only be obtained at the temperature higher than 1 700 K.

show abstract

Section: Introductionmentioning

confidence: 99%

Melting and Reduction Behaviour of Individual Fine Hematite Ore Particles

Yang

Zou

et al. 2015

ISIJ International

View full text Add to dashboard Cite

show abstract

“…[5][6][7][8][9][10][11][12][13] The reduction processes use a reducing gas produced by steam reforming of natural gas. Therefor the reducing gas is a mixture of H 2 , CO, CO 2 , CH 4 , N 2 and H 2 O.…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on the Kinetics of Fluidized Bed Iron Ore Reduction.

Habermann¹,

Winter²,

Hofbauer³

et al. 2000

ISIJ International

View full text Add to dashboard Cite

To optimize existing iron ore reduction processes or to develop new ones, it is necessary to know the reduction kinetics of the iron ore of interest under the relevant operating conditions. In this work the reduction kinetics of hematite fine iron ore was studied for industrial-scale processes using the fluidized bed technology. Especially designed batch tests were performed in a laboratory-scale fluidized bed reactor fluidized with H 2 , H 2 O, CO, CO 2 , N 2 at atmospheric and elevated pressures to simulate the relevant process conditions. To obtain the reduction rates and the degree of reduction, the concentrations of H 2 O, CO, and CO 2 in the outlet gas were analyzed by FT-IR spectroscopy.Preliminary reduction tests showed a strong effect of the sample weight on the reduction rates, especially in the early stages of reduction. The optimum sample weight was determined by partly replacing the hematite with silica sand. Additionally, the silica sand provided a constant and stable flow pattern throughout the reduction tests. The effects of temperature, gas composition, particle size and pressure on the rates of reduction were tested and discussed.Rate analysis showed the existence of two phases with different rates during the reduction tests. Additional investigations (microscope analysis, SEM) demonstrated that in the first phase the rates were controlled by mass transport in the gas phase and in the second phase by the reduction process within the small grains of the iron ore particles.KEY WORDS: iron ore reduction; high temperature fluidized bed; reduction kinetics; elevated pressure; H 2 -CO gas mixture.

show abstract

“…However, the using of fine iron ore particles leads to new challenges on operation and unknowns on reaction mechanism at the same time. Up to now, the intensive experimental studies on iron ore fines have been carried out with laboratory-scale fluidized bed reactor [5][6][7][8][9] and gas conveyed system. 10,11) The experimental studies with the laboratory-scale fluidized bed reactor were successfully applied to analyse the gas-solid particle reduction mechanism in the fluidized bed reactors which are used in the direct reduction processes and the prereduction stage of smelting reduction processes.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2015

View full text Add to dashboard Cite

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.

show abstract

Kinetics of reduction of ferrous oxide with hydrogen in a fluidized bed at steady state

Cited by 18 publications

References 7 publications

Melting and Reduction Behaviour of Individual Fine Hematite Ore Particles

Melting and Reduction Behaviour of Individual Fine Hematite Ore Particles

An Experimental Study on the Kinetics of Fluidized Bed Iron Ore Reduction.

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

Contact Info

Product

Resources

About