Fate of titanium in alkaline electro-reduction of sintered titanomagnetite

10.26686/wgtn.14331635.v1 ◽

2021 ◽

Author(s):

O Bjareborn ◽

Tanzeel Arif ◽

B Monaghan ◽

Christopher Bumby

Keyword(s):

Reaction Front ◽

Iron Ore ◽

Reduction Process ◽

Ti Oxides ◽

Iron Metal ◽

Reduction Of Iron ◽

Iron Titanate ◽

Commercial Iron ◽

Ti Content ◽

Preferential Alignment

Direct electrochemical reduction of iron ore in concentrated NaOH electrolyte has been proposed as a potential route to substantially reducing the global steel industry’s CO2 emissions. Here, we report the solid-state electro-reduction of sintered pellets formed from titanomagnetite ironsand. This commercial iron ore contains ∼4 wt.% Ti which is directly incorporated within the magnetite lattice. At 110 °C, these pellets are electrochemically reduced and exhibit a well-defined reaction front which moves into the pellet as the reaction progresses. The electro-reduction process selectively produces iron metal, whilst the Ti content is not reduced. Instead, Ti becomes enriched in segregated oxide inclusions, which are subsequently transformed to a sodium iron titanate phase through taking up Na+ from the electrolyte. These inclusions adopt an elongated shape and appear to exhibit locally preferential alignment. This suggests that they may nucleate from the microscopic titanohematite lamellae which naturally occur within the original ironsand particles. The expulsion of contaminant Ti-oxides from the final reduced metal matrix has implications for the potential to development of an industrial electrochemical iron-making process utilising titanomagnetite ore. © 2020 The Author(s). Published by IOP Publishing Ltd.

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Slag Formation during Reduction of Iron Oxide Using Hydrogen Plasma Smelting Reduction

Materials ◽

10.3390/ma13040935 ◽

2020 ◽

Vol 13 (4) ◽

pp. 935 ◽

Cited By ~ 1

Author(s):

Masab Naseri Seftejani ◽

Johannes Schenk ◽

Daniel Spreitzer ◽

Michael Andreas Zarl

Keyword(s):

Iron Oxides ◽

Iron Ore ◽

Hydrogen Plasma ◽

Reduction Process ◽

Slag Formation ◽

Smelting Reduction ◽

Steel Making ◽

Reduction Of Iron ◽

Reduction Behaviour ◽

Continuous Feeding

Replacing carbon by hydrogen is a huge step towards reducing CO2 emissions in the iron- and steel-making industry. The reduction of iron oxides using hydrogen plasma smelting reduction as an alternative to conventional steel-making routes has been studied at Montanuniversitaet Leoben, Austria. The aim of this work was to study the slag formation during the reduction process and the reduction behaviour of iron oxides. Furthermore the reduction behaviour of iron ore during continuous feeding was assessed. Mixtures of iron ore and calcined lime with a basicity of 0, 0.8, 1.6, 2.3, and 2.9 were melted and reduced by hydrogen. The off-gas composition was measured during the operations to calculate the process parameters. The reduction parameters, namely the degree of reduction, degree of hydrogen utilisation, produced iron, and slag, are presented. The results of the batch-charged experiments showed that at the beginning of the reduction process, the degree of hydrogen utilisation was high, and then, it decreased over the operation time. In contrast, during the continuous-feeding experiment, the degree of hydrogen utilisation could be kept approximately constant. The highest degrees of reduction and hydrogen utilisation were obtained upon the application of a slag with a basicity of 2.3. The experiment showed that upon the continuous feeding of iron ore, the best conditions for the reduction process using hydrogen could be applied.

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Physics and Chemistry of Solid State Direct Reduction of Iron Ore by Hydrogen Plasma

Фізика і хімія твердого тіла ◽

10.15330/pcss.22.2.292-300 ◽

2021 ◽

Vol 22 (2) ◽

pp. 292-300

Author(s):

Kali Charan Sabat

Keyword(s):

Solid State ◽

Large Scale ◽

Iron Ore ◽

Direct Reduction ◽

Hydrogen Plasma ◽

Standard Free Energy ◽

Reduction Process ◽

Capital Investments ◽

State Reduction ◽

Reduction Of Iron

Presently, Iron is produced from iron ores by using carbon from coal. The production process is consisting of many stages. The involvement of multi-stages needs high capital investments, large-scale equipments, and produces large amounts of carbon dioxide (CO2) responsible for environmental pollution. There have been significant efforts to replace carbon with hydrogen (H2). Although H2 is the strongest reductant, it still also has thermodynamic and kinetic limitations. However, these thermodynamic and kinetic limitations could be removed by hydrogen plasma (HP). HP comprises rovibrationally excited molecular, atomic, and ionic states of hydrogen. All of them contribute to thermodynamic advantage by making the Gibbs standard free energy more negative, which makes the reduction of iron oxides feasible at low temperatures. Apart from the thermodynamic advantage, these excited species increase the internal energy of HP, which reduces the activation energy, thereby making the reduction easier and faster. Apart from the thermodynamic and kinetic advantage of HP, the byproduct of the reaction is environmentally benign water. This review discusses the physics and chemistry of iron ore reduction using HP, emphasizing the solid-state reduction of iron ore. HP reduction of iron ore is a high potential and attractive reduction process.

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The sticking problem during direct reduction of fine iron ore in the fluidized bed

Metalurgija-Journal of Metallurgy ◽

10.30544/378 ◽

2004 ◽

Vol 10 (4) ◽

pp. 309-328 ◽

Cited By ~ 51

Author(s):

Mirko Komatina ◽

HEINRICH W. GUDENAU

Keyword(s):

Fluidized Bed ◽

Iron Ore ◽

Review Paper ◽

Direct Reduction ◽

Reduction Process ◽

Experimental Investigations ◽

Inert Material ◽

Reduction Of Iron ◽

Fine Iron ◽

Direct Reduction Of Iron

In this review paper described are possible chemical reactions and their thermodynamic analysis during direct reduction. The sticking mechanism during direct reduction in the fluidized bed was analysed, and the reasons for the sticking appearance explained. The most important parameters on the sticking were analysed. The ways for prevention and observation were considered. The plan for experimental investigations was proposed. The investigations could be performed in fluidized bed reactor. Coal will be used as inert material. Separately, the influence volatile content in the coal on the reduction process and sticking appearance, will be analysed. As results of these investigations would be some improvements of the method direct reduction of iron ore in the fluidized bed.

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The Influence of Coal and Reduction Process Parameters in Producing Iron Nugget

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.789.517 ◽

2013 ◽

Vol 789 ◽

pp. 517-521 ◽

Cited By ~ 4

Author(s):

Johny Wahyuadi Soedarsono ◽

Adji Kawigraha ◽

Rianti Dewi Sulamet-Ariobimo ◽

M. Amryl Asy'ari ◽

Andre Yosi ◽

...

Keyword(s):

Carbon Source ◽

Iron Ore ◽

Iron Reduction ◽

Reduction Process ◽

High Quality ◽

Composite Pellet ◽

Iron And Steel ◽

Iron Metal ◽

Iron Nugget ◽

Weak Peak

Limitation of iron ore reserve having high quality ore and of energy has enhanced development in iron and steel producing technology and method. The ITmk3 process is one of iron making technology that can cope with the problems. It uses composite pellet as feeding material. In this process the ratio between iron and carbon are very important. Carbon holds an important role in the reduction process of iron. The transformation from iron oxides to iron metal will complete if composite pellet contains enough carbon. This paper discusses the influence of carbon ratio in iron reduction process. Nickel saprolite and coal are used as iron and carbon source. They are grinded, crushed, sieved, mixed and formed in cylinders. The weight ratios of ores to coal are 1:1 and 2:1. The reduction held in a furnace at 1100OC for 60 minutes and 1250OC for 120 minutes. The results show that the reduction could not complete. Weak peak of FeNi is due to reduction process do not immediately follow the dehydroxylation process.

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Perolehan Tio2 Dari Iron Ore Mengandung Titanium Melalui Proses Reduksi Karbon Dan Pelarutan Asam

INDONESIAN JOURNAL OF APPLIED PHYSICS ◽

10.13057/ijap.v2i02.1288 ◽

2016 ◽

Vol 2 (02) ◽

pp. 37

Author(s):

Elda Rayhana ◽

Azwar Manaf

Keyword(s):

Tin Oxide ◽

Iron Ore ◽

Raw Materials ◽

Acid Leaching ◽

Reduction Process ◽

Successive Stage ◽

Pig Iron ◽

Carbon Reduction ◽

Fine Powders ◽

Reduction Of Iron

REDUCTION AND LEACHING PROCESSES. Indonesia has a large source of iron ore which is quite tempting for the purposes of exploitation in form of raw materials as well as for the production of pig iron. However, not all sources of iron ore are proved useful since not only because the present of deposit is scattere dinamounts of less significant but also because it contains element of tin oxide compounds with iron like ilmenite or FeTiO3. However,ilmenite can actually be used as a source of titanium metal which is much more valuable than Fe it self. In order to recover the Ti from their respective compound it is required the release of strong bonds between the atoms in the compound. This paper reports the recovery of Ti oxide of ilmenite containing iron ore which was obtained through a combination of carbon reduction and acid leaching processes. Carbon reduction of iron ore was carried out through mechanical milling between iron ore and carbon with a ratio of 1:1. This was successively followed by a sintering at a temperature of 1000 oC employing a heating rate of 10 ° C/min for 0-3 hours. The reduction process has resulted in the formation of 27.83wt% TiO2. In order to improve the recovery level of TiO2, further reduction process was conducted through an HCl leaching. This successive stage produced fine powders in the form of deposits. Based on our quantitative analysis, the recovery of TiO2 increased to a level of 73.73%.

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Slag Formation During Reduction of Iron Oxide Using Hydrogen Plasma Smelting Reduction

10.20944/preprints202001.0337.v1 ◽

2020 ◽

Author(s):

Masab Naseri Seftejani ◽

Johannes Schenk ◽

Daniel Spreitzer ◽

Michael Andreas Zarl

Keyword(s):

Iron Oxides ◽

Iron Ore ◽

Hydrogen Plasma ◽

Reduction Process ◽

Slag Formation ◽

Smelting Reduction ◽

Steel Making ◽

Reduction Of Iron ◽

Reduction Behaviour ◽

Continuous Feeding

Replacing carbon by hydrogen is a huge step towards reducing CO2 emissions in the iron- and steel-making industry. The reduction of iron oxides using hydrogen plasma smelting reduction as an alternative to conventional steel-making routes has been studied at Montanuniversitaet Leoben, Austria. The aim of this work was to study the slag formation during the reduction process and the reduction behaviour of iron oxides. Furthermore, the reduction behaviour of iron ore during continuous feeding was assessed. Mixtures of iron ore and calcined lime with a basicity of 0, 0.8, 1.6, 2.3, and 2.9 were melted and reduced by hydrogen. The off-gas composition was measured during the operations to calculate the process parameters. The reduction parameters, namely the degree of reduction, degree of hydrogen utilisation, produced iron, and slag, are presented. The results of the batch-charged experiments showed that at the beginning of the reduction process, the degree of hydrogen utilisation was high, and then, it decreased over the operation time. In contrast, during the continuous-feeding experiment, the degree of hydrogen utilisation could be kept approximately constant. The highest degrees of reduction and hydrogen utilisation were obtained upon the application of a slag with a basicity of 2.3. The experiment showed that upon the continuous feeding of iron ore, the best conditions for the reduction process using hydrogen could be applied.

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

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2021-3-262-271 ◽

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.

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