Observation and modeling of the reduction of hematite particles to metal in alkaline solution by electrolysis

Allanore, Antoine; Lavelaine, H.; Valentin, G.; Birat, Jean‐Pierre; Delcroix, P.; Lapicque, François

doi:10.1016/j.electacta.2010.02.040

Cited by 75 publications

(90 citation statements)

References 7 publications

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“…The reduction-generated Fe phase and the unreacted Fe 2 O 3 phase can be clearly identified, therefore, the third phase may be attributed to the intermediate products, such as Fe 3 O 4 . [16] These observations further confirm that the concentration of NaOH aqueous electrolyte can influence the reaction process.…”

Section: B Influence Of the Concentration Of Naoh Aqueous Electrolytsupporting

confidence: 73%

“…Cox and Fray [12,13] pioneered their work on the iron production from Fe(III) oxide by electrochemical reduction at a lower temperature of about 803 K (530°C) in molten NaOH. Allanore et al [16] proved that hematite particles could be electrochemically reduced to iron in 50 wt pct aqueous NaOH solution at 383 K (110°C). Yuan et al [14] investigated the electrowinning of iron deposits from iron oxides in 50 wt pct aqueous NaOH solution at 387 K (114°C) with a rotating cathode.…”

Section: Introductionmentioning

confidence: 99%

“…[15,16] Electrolytic production of iron is expected to be capable of sustaining a reasonably low-carbon emission as demonstrated in aqueous solutions and molten salts. [1][2][3][4][5][6][7][10][11][12][13][14][15][16][17][18] Although electrochemical extraction of aluminum has achieved great success due to the electrodeposition process occurs. However, it still remains a challenge to extend the electrodeposition process to iron-based materials production since it requires dissolved raw materials and liquid metallic product.…”

Section: Introductionmentioning

confidence: 99%

“…[4] Therefore, in recent years, the environmentally friendly processes, such as the electrochemical processes have been widely investigated as potential green routes for the production of iron and iron-base alloys. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The ultra-low CO 2 steelmaking (ULCOS) program was set up in Europe with the aim of developing new technologies to reduce greenhouse gases emissions in iron production. [15,16] Electrolytic production of iron is expected to be capable of sustaining a reasonably low-carbon emission as demonstrated in aqueous solutions and molten salts.…”

Section: Introductionmentioning

confidence: 99%

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] The ultra-low CO 2 steelmaking (ULCOS) program was set up in Europe with the aim of developing new technologies to reduce greenhouse gases emissions in iron production. [15,16] Electrolytic production of iron is expected to be capable of sustaining a reasonably low-carbon emission as demonstrated in aqueous solutions and molten salts. [1][2][3][4][5][6][7][10][11][12][13][14][15][16][17][18] Although electrochemical extraction of aluminum has achieved great success due to the electrodeposition process occurs.…”

Section: Introductionmentioning

confidence: 99%

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Electroreduction of Iron(III) Oxide Pellets to Iron in Alkaline Media: A Typical Shrinking-Core Reaction Process

Zou

et al. 2015

Metall Mater Trans B

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Low temperature electrochemical reduction of iron(III) oxide to iron in a strongly alkaline solution has been systematically investigated in this article. The facile electrochemical process was carried out in 50 to 70 wt pct aqueous NaOH solution at 383 K (110°C) and 1.7 V. The preformed spherical Fe 2 O 3 pellets with porous structures were used directly as precursors for the electrolytic production of iron. The influences of the experimental parameters on the electroreduction process and the characteristics of the iron products as well as the reaction mechanisms were investigated. The results show that the precursor's pre-sintering process and the concentration of NaOH aqueous electrolyte have significant influences on the electroreduction process. The electroreduction-generated spherical metallic iron layer comprising dendritic iron crystals is first formed on the surface of Fe 2 O 3 pellet precursor and then extends gradually into the pellet's interior along the radial direction. The electroreduction process is confirmed to be a typical shrinking-core reaction process. The direct solid state electroreduction mechanism and the dissolution-electrodeposition mechanism coexist in the electrochemical process. The experimental observations suggest that the dissolution-electrodeposition mechanism appears to be the dominant mechanism under the experimental conditions employed in this study. This facile process may open a new green electricitybased route for the production of dendritic iron crystals from iron(III) oxide in alkaline media.

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Section: B Influence Of the Concentration Of Naoh Aqueous Electrolytsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Electroreduction of Iron(III) Oxide Pellets to Iron in Alkaline Media: A Typical Shrinking-Core Reaction Process

Zou

et al. 2015

Metall Mater Trans B

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Stainless Steel Activation for Efficient Alkaline Oxygen Evolution in Advanced Electrolyzers

Zuo,

Mastronardi,

Gamberini

et al. 2024

Advanced Materials

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Designing robust and cost‐effective electrocatalysts for efficient alkaline oxygen evolution reaction (OER) is of great significance in the field of water electrolysis. In this study, we introduce an electrochemical strategy to activate stainless steel (SS) electrodes for efficient OER. By cycling the SS electrode within a potential window that encompasses the Fe(II)↔Fe(III) process, we can greatly enhance its OER activity compared to using a potential window that excludes this redox reaction, decreasing the overpotential at current density of 100 mA cm−2 by 40 mV. Electrochemical characterization, Inductively Coupled Plasma – Optical Emission Spectroscopy and operando Raman measurements demonstrated that the Fe leaching at the SS surface can be accelerated through a Fe → γ‐Fe2O3 → Fe3O4 or FeO → Fe2+ (aq.) conversion process, leading to the sustained exposure of Cr and Ni species. While Cr leaching occurs during its oxidation process, Ni species display higher resistance to leaching and gradually accumulate on the SS surface in the form of OER‐active Fe‐incorporated NiOOH species. Furthermore, a potential‐pulse strategy was also introduced to regenerate the OER‐activity of 316‐type SS for stable OER, both in the three‐electrode configuration (without performance decay after 300 h at 350 mA cm−2) and in an alkaline water electrolyzer (ca. 30 mV cell voltage increase after accelerated stress test‐AST). The AST‐stabilized cell can still reach 1000 mA cm−2 and 4000 mA cm−2 at cell voltages of 1.69 V and 2.1 V, which makes it competitive with state‐of‐the‐art electrolyzers based on ion‐exchange‐membranes using Ir‐based anodes.This article is protected by copyright. All rights reserved

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Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

Bae

Kim

et al. 2023

Advanced Science

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Iron making is the biggest single cause of global warming. The reduction of iron ores with carbon generates about 7% of the global carbon dioxide emissions to produce ≈1.85 billion tons of steel per year. This dramatic scenario fuels efforts to re‐invent this sector by using renewable and carbon‐free reductants and electricity. Here, the authors show how to make sustainable steel by reducing solid iron oxides with hydrogen released from ammonia. Ammonia is an annually 180 million ton traded chemical energy carrier, with established transcontinental logistics and low liquefaction costs. It can be synthesized with green hydrogen and release hydrogen again through the reduction reaction. This advantage connects it with green iron making, for replacing fossil reductants. the authors show that ammonia‐based reduction of iron oxide proceeds through an autocatalytic reaction, is kinetically as effective as hydrogen‐based direct reduction, yields the same metallization, and can be industrially realized with existing technologies. The produced iron/iron nitride mixture can be subsequently melted in an electric arc furnace (or co‐charged into a converter) to adjust the chemical composition to the target steel grades. A novel approach is thus presented to deploying intermittent renewable energy, mediated by green ammonia, for a disruptive technology transition toward sustainable iron making.

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Observation and modeling of the reduction of hematite particles to metal in alkaline solution by electrolysis

Cited by 75 publications

References 7 publications

Electroreduction of Iron(III) Oxide Pellets to Iron in Alkaline Media: A Typical Shrinking-Core Reaction Process

Electroreduction of Iron(III) Oxide Pellets to Iron in Alkaline Media: A Typical Shrinking-Core Reaction Process

Stainless Steel Activation for Efficient Alkaline Oxygen Evolution in Advanced Electrolyzers

Reducing Iron Oxide with Ammonia: A Sustainable Path to Green Steel

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