The reduction of iron ores by hydrogen and carbon monoxide and their mixtures

Hughes, R.; Kam, E.K.T.; Mogadam-Zadeh, H.

doi:10.1016/0040-6031(82)87158-x

Cited by 16 publications

(14 citation statements)

References 9 publications

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“…It has been reported that CO present in the reducing gas can deposit carbon on pellet's surface, according to Boudouard reaction (Eq. 6) [38,39]. Such fact can be confirmed via X-ray pattern on the pellet's surface reduced up to 600°C (Fig.…”

Section: Reduction Of Eafd Pelletssupporting

confidence: 66%

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Junca

Restivo

Oliveira

et al. 2016

J Therm Anal Calorim

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The purpose of this paper is to study the kinetic reaction of electric arc furnace dust pellets using a reducing gas simulating the reformed natural gas. The kinetic investigation was accomplished via forced stepwise isothermal analysis method. The tests were programmed in the range of 500-1000°C. It was used a reducing gas contained 25 % of CO and 75 % of H 2 . X-ray patterns were analyzed in order to understand the reduction process. The results show the reduction of electric arc furnace dust pellet occurs in three steps. At 550-650°C, the zinc ferrite is reduced to magnetite and zinc oxide, followed by the reduction of magnetite to wustite. Carbon deposition on the pellet surface was detected in this step, which impairs the kinetic analysis. In the range of 700-800°C, wustite is reduced to iron. It was determined a mixed control between nucleation and diffusion with E a of 89.2 kJ mol -1 . At 850-950°C, the main reaction is zinc oxide reduction to gaseous zinc. However, wustite reduction is also observed. The E a of 135.5 kJ mol -1 with a mixed control between diffusion and chemical reaction was detected.

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Section: Reduction Of Eafd Pelletssupporting

confidence: 66%

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Junca

Restivo

Oliveira

et al. 2016

J Therm Anal Calorim

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“…Hydrogen has been used as a primary rocket fuel for combustion with oxygen or uorine and is favored as a propellant for nuclear-powered rockets and space vehicles [21,22]. Another increasing use of hydrogen is in the direct reduction of iron ores to metallic iron and in the reduction of the oxides of tungsten and molybdenum to the metals [23,24]. A hydrogen atmosphere is employed in the pouring of special castings, in the manufacture of magnesium, in the annealing of metals, and for the cooling of large electric motors [25,26].…”

Section: Introductionmentioning

confidence: 99%

WITHDRAWN: Effects of wall heat conduction properties on the methanol reforming process characteristics of microchannel reactors for hydrogen production

Chen

2022

Preprint

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This study relates to a thermochemical process for producing hydrogen by the catalytic endothermic reaction of methanol with steam in a thermally integrated microchannel reforming reactor. Computational fluid dynamics simulations are conducted to better understand the consumption, generation, and exchange of thermal energy between endothermic and exothermic processes in the reactor. The effects of wall heat conduction properties on the methanol reforming process characteristics of microchannel reactors for hydrogen production are investigated. Particular emphasis is placed on the dependence of heat transfer characteristics on wall heat conduction properties in various situations, with an attempt to improve the distribution of thermal energy for use in microchannel reforming reaction systems for hydrogen production. The results indicate that the reactor design suffers from a fundamental limitation resulting from the flow configuration in which a reacting stream flows parallel to a heat transfer surface through which the majority of heat is transferred perpendicular to the direction of fluid flow. The thermal conductivity of the channel walls is fundamentally important. Materials with high thermal conductivity are preferred for the channel walls. Thermally conductive ceramics and metals are well-suited. Wall materials with poor heat conduction properties degrade the reactor performance. Balancing the heat requirements of an endothermic reaction with heat generated by an exothermic reaction flowing parallel to and on the opposite side of a separating plate is extraordinarily difficult. Along the flow length of the plate that divides exothermic and endothermic reactions, the heat flux through the plate that is perpendicular to fluid flow will vary due to temperature and reaction rate differences along the flow length of the plate.

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“…Numerous studies have reported the reduction kinetics of iron ore by H 2 or H 2 -containing mixtures [3][4][5]10,[13][14][15][16][17][18][19][20][21]. The experimental research of Pineau et al [18] indicates that the reduction path of hematite is as follows:…”

Section: Of 10mentioning

confidence: 99%

“…Direct reduction is one of the promising alternative ironmaking processes to effectively reduce carbon emission. It has been realized that H 2 is a more ideal reducing agent comparing with CO in the aspect of kinetics [3,4]. Moreover, H 2 is a clear energy and H 2 reduction is a much more environmentally friendly method.…”

Section: Introductionmentioning

confidence: 99%

Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures

Chen

Dang

et al. 2018

Metals

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Hydrogen has received much attention in the development of direct reduction of iron ores because hydrogen metallurgy is one of the effective methods to reduce CO2 emission in the iron and steel industry. In this study, the kinetic mechanism of reduction of hematite particles was studied in a hydrogen atmosphere. The phases and morphological transformation of hematite during the reduction were characterized using X-ray diffraction and scanning electron microscopy with energy dispersive spectroscopy. It was found that porous magnetite was formed, and the particles were degraded during the reduction. Finally, sintering of the reduced iron and wüstite retarded the reductive progress. The average activation energy was extracted to be 86.1 kJ/mol and 79.1 kJ/mol according to Flynn-Wall-Ozawa (FWO) and Starink methods, respectively. The reaction fraction dependent values of activation energy were suggested to be the result of multi-stage reactions during the reduction process. Furthermore, the variation of activation energy value was smoothed after heat treatment of hematite particles.

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The reduction of iron ores by hydrogen and carbon monoxide and their mixtures

Cited by 16 publications

References 9 publications

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

Reduction of electric arc furnace dust pellets by simulated reformed natural gas

WITHDRAWN: Effects of wall heat conduction properties on the methanol reforming process characteristics of microchannel reactors for hydrogen production

Reduction Kinetics of Hematite Powder in Hydrogen Atmosphere at Moderate Temperatures

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