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Publications (10 of 56) Show all publications
Ni, P., Tanaka, T., Suzuki, M., Nakamoto, M. & Jönsson, P. (2019). A Kinetic Model of Mass Transfer and Chemical Reactions at a Steel/Slag Interface under Effect of Interfacial Tensions. ISIJ International, 59(5), 737-748
Open this publication in new window or tab >>A Kinetic Model of Mass Transfer and Chemical Reactions at a Steel/Slag Interface under Effect of Interfacial Tensions
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2019 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 59, no 5, p. 737-748Article in journal (Refereed) Published
Abstract [en]

A new kinetic model was developed to predict the dynamic change of the interfacial oxygen content and the steel/slag interfacial tension. This model mainly describes the following interfacial physicochemical phenomena: i) Silica decomposition and oxygen adsorption at the interface, ii) Oxygen and aluminum reactions at the interface, iii) Oxygen desorption from the interface, iv) Silica mass transfer from the slag to the interface, v) Dissolution of the formed alumina into the slag and its transfer in slag and vi) Blockage on the silica mass transfer, to come in contact with the steel, by the accumulation of the formed alumina at the interface. With this model, the dynamic changes of the interfacial oxygen contents under different aluminum contents in steel and different slag viscosities were predicted. Overall, the interfacial oxygen content was found to increase with a decreased aluminum content and a decreased slag viscosity. Furthermore, the aluminum reaction rate can significantly influence the interfacial oxygen content as well as the interfacial tension. In addition, the model captured the fast increase of the interfacial tension after passing the minimum value point for the system of a high -Al content steel and a low viscous slag, which is in agreement with the experimental observations. Furthermore, a parameter study was carried out to show the influence of various parameters on the dynamic interfacial phenomena.

Place, publisher, year, edition, pages
IRON STEEL INST JAPAN KEIDANREN KAIKAN, 2019
Keywords
steel-slag interfacial tension, mass transfer, thermodynamics and kinetics, interfacial reactions, dynamic modeling
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-254046 (URN)10.2355/isijintemational.ISIJINT-2018-496 (DOI)000469406900001 ()2-s2.0-85069161312 (Scopus ID)
Note

QC 20190813

Available from: 2019-08-13 Created: 2019-08-13 Last updated: 2019-10-04Bibliographically approved
Liu, Y., Ersson, M., Liu, H., Jönsson, P. G. & Gan, Y. (2019). A Review of Physical and Numerical Approaches for the Study of Gas Stirring in Ladle Metallurgy. Metallurgical and materials transactions. B, process metallurgy and materials processing science, 50(1), 555-577
Open this publication in new window or tab >>A Review of Physical and Numerical Approaches for the Study of Gas Stirring in Ladle Metallurgy
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2019 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 50, no 1, p. 555-577Article, review/survey (Refereed) Published
Abstract [en]

This article presents a review of the research into gas stirring in ladle metallurgy carried out over the past few decades. Herein, the physical modeling experiments are divided into four major areas: (1) mixing and homogenization in the ladle; (2) gas bubble formation, transformation, and interactions in the plume zone; (3) inclusion behavior at the steel-slag interface and in the molten steel; and (4) open eye formation. Several industrial trials have also been carried out to optimize gas stirring and open eye formation. Approaches for selecting criteria for scaling to guarantee flow similarity between industrial trials and physical modeling experiments are discussed. To describe the bubble behavior and two-phase plume structure, four main mathematical models have been used in different research fields: (1) the quasi-single-phase model, (2) the volume of fluid (VOF) model, (3) the Eulerian multiphase (E-E) model, and (4) the Eulerian-Lagrangian (E-L) model. In recent years, the E-E model has been used to predict gas stirring conditions in the ladle, and specific models in commercial packages, as well as research codes, have been developed gradually to describe the complex physical and chemical phenomena. Furthermore, the coupling of turbulence models with multiphase models is also discussed. For physical modeling, some general empirical rules have not been analyzed sufficiently. Based on a comparison with the available experimental results, it is found that the mathematical models focusing on the mass transfer phenomenon and inclusion behaviors at the steel-slag interface, vacuum degassing at the gas-liquid interface, dissolution rate of the solid alloy at the liquid-solid interface, and the combination of fluid dynamics and thermodynamics need to be improved further. To describe industrial conditions using mathematical methods and improve numerical modeling, the results of physical modeling experiments and industrial trials must offer satisfactory validations for the improvement of numerical modeling.

Place, publisher, year, edition, pages
SPRINGER, 2019
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-243935 (URN)10.1007/s11663-018-1446-x (DOI)000456070300052 ()2-s2.0-85056988962 (Scopus ID)
Note

QC 20190313

Available from: 2019-03-13 Created: 2019-03-13 Last updated: 2019-03-13Bibliographically approved
Al-Saadi, M., Sandberg, F., Hulme-Smith, C., Karasev, A. & Jönsson, P. (2019). A study of the static recrystallization behaviour of cast Alloy 825 after hot-compressions. Paper presented at 7th International Conference on Recrystallization and Grain Growth, Ghent,August 4-9, 2019. IOP Conference Series: Materials Science and Engineering, 1270
Open this publication in new window or tab >>A study of the static recrystallization behaviour of cast Alloy 825 after hot-compressions
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2019 (English)In: IOP Conference Series: Materials Science and Engineering, ISSN 1757-8981, E-ISSN 1757-899X, Journal of Physics, Vol. 1270Article in journal, Editorial material (Refereed) Published
Abstract [en]

The static recrystallization behaviour of a columnar and equiaxed Alloy 825 material was studied on a Gleeble-3800 thermo-simulator by single-hit compression experiments. Deformation temperatures of 1000-1200 °C, a strain of up to 0.8, a strain rate of 1s-1, and relaxation times of 30, 180, and 300 s were selected as the deformation conditions to investigate the effects of the deformation parameters on the SRX behaviour. Furthermore, the influences of the initial grain structures on the SRX behaviors were studied. The microstructural evolution was studied using optical microscopy and EBSD. The EBSD measurements showed a relaxation time of 95 % for fractional recrystallization grains, 𝑡95, in both structures, was less than 30 seconds at the deformation temperatures 1100 °C and 1200 °C. However, fewer than 95% of recrystallized grains recrystallized when the deformation temperature was lowered to 1000 °C. From the grain-boundary misorientation distribution in statically recrystallized samples, the fraction of high-angle grain boundaries decreased with an increasing deformation temperature from 1000 °C to 1200 °C for a given relaxation time. This was attributed to grain coarsening

Keywords
Alloy 825, Static recrystallization, hot compression, Gleeble-3800 thermo simulator
National Category
Metallurgy and Metallic Materials
Research subject
Materials Science and Engineering
Identifiers
urn:nbn:se:kth:diva-258210 (URN)10.1088/1742-6596/1270/1/012023 (DOI)
Conference
7th International Conference on Recrystallization and Grain Growth, Ghent,August 4-9, 2019
Note

QC 20190916

Available from: 2019-09-10 Created: 2019-09-10 Last updated: 2019-09-16Bibliographically approved
Nakajima, K., Mu, W. & Jönsson, P. (2019). Assessment of a Simplified Correlation Between Wettability Measurement and Dispersion/Coagulation Potency of Oxide Particles in Ferrous Alloy Melt. Metallurgical and materials transactions. B, process metallurgy and materials processing science, 50(5), 2229-2237
Open this publication in new window or tab >>Assessment of a Simplified Correlation Between Wettability Measurement and Dispersion/Coagulation Potency of Oxide Particles in Ferrous Alloy Melt
2019 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 50, no 5, p. 2229-2237Article in journal (Refereed) Published
Abstract [en]

This article seeks to demonstrate a direct and simplified correlation between the measurement of the wettability and the agglomeration potency of the inclusion particles in liquid ferrous alloy. The established methodology has been validated by the agreement between the calculated coagulation coefficient of Al2O3 particles and the experimental data in the open literature. Subsequently, the coagulation coefficient of Al2O3, MgO, and Ti2O3 particles in ferrous alloy melts was evaluated quantitatively by the proposed method using the actual experimental data of contact angle and surface tension. Meanwhile, the effect of the matrix composition has been investigated by comparing the Hamaker constant and coagulation coefficient between Ti2O3/pure iron and Ti2O3/low-carbon steel systems. It is noted that the change of coagulation coefficient associated with the contact angle is caused by the formation of a new phase at the oxide/metal interface at the high temperature. The present work aims to provide a deep understanding of the connection between inclusion motion behavior in the liquid alloy and the high temperature interfacial phenomenon.

Place, publisher, year, edition, pages
SPRINGER, 2019
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-261293 (URN)10.1007/s11663-019-01624-x (DOI)000486025000014 ()2-s2.0-85068126410 (Scopus ID)
Note

QC 20191008

Available from: 2019-10-08 Created: 2019-10-08 Last updated: 2019-10-08Bibliographically approved
Jarnerud, T., Karasev, A. & Jönsson, P. G. (2019). Briquetting of wastes from pulp and paper industries by using AOD converter slag as binders for application in metallurgy. Materials, 12(18), Article ID 2888.
Open this publication in new window or tab >>Briquetting of wastes from pulp and paper industries by using AOD converter slag as binders for application in metallurgy
2019 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, no 18, article id 2888Article in journal (Refereed) Published
Abstract [en]

A number of carbon-rich (containing up to 47 wt% C) and lime-rich (containing up to 96 wt% of CaO-compounds) waste products from the pulp and paper industries can be used in iron and steel industry as fuels and slag formers for various metallurgical processes such as blast furnaces (BF), cupola furnaces (CF), argon oxygen decarburization (AOD) converters and electric arc furnaces (EAF). In most cases, these wastes consist of different size powders. In order to facilitate loading, transportation and charging of these powder wastes, briquetting is required. In this study, a pulverized AOD slag was tested as a binder component for briquetting of CaO-containing wastes (such as mesa, lime mud and fly ash) from pulp and paper industries. Moreover, mechanical testing of the possibilities for loading, transportation and unloading operations were done, specifically drop test trials were done for briquettes with different chemical compositions and treatments such as heating and storage. The results showed that an addition of 10-20% of AOD slag as a binder component followed by heat-treatment at 850 °C significantly improved the mechanical properties of the CaO-containing briquettes. An application of these briquettes will significantly reduce the consumption of natural resources (such as nature lime) in the metallurgical processes. Moreover, it can reduce the landfill area of wastes from pulp and paper industries, which is important from an environmental point-of-view.

Place, publisher, year, edition, pages
MDPI AG, 2019
Keywords
Metallurgical briquettes, Recirculation of wastes, Resource saving, Secondary raw materials
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-262500 (URN)10.3390/ma12182888 (DOI)2-s2.0-85072564307 (Scopus ID)
Note

QC 20191017

Available from: 2019-10-17 Created: 2019-10-17 Last updated: 2019-10-17Bibliographically approved
Han, T., Ding, S., Yang, W. & Jönsson, P. (2019). Catalytic pyrolysis of lignin using low-cost materials with different acidities and textural properties as catalysts. Chemical Engineering Journal, 373, 846-856
Open this publication in new window or tab >>Catalytic pyrolysis of lignin using low-cost materials with different acidities and textural properties as catalysts
2019 (English)In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 373, p. 846-856Article in journal (Refereed) Published
Abstract [en]

Catalytic fast pyrolysis of lignin was performed using low-cost materials with different acidities and textural properties as catalysts in the present work. The main focus is to understand the role of low-cost catalysts in the fast pyrolysis of lignin. The four most commonly used low-cost catalysts, ilmenite (FeTiO3), bentonite (Al-Si-OH), activated carbon (AC) and red mud (RM), were selected. The results show that bentonite, red mud and activated carbon effectively enhance the dehydration reaction, which is regarded as the dominant way to eliminate oxygen during the pyrolysis process, due to the existence of strong acidic sites. However, only activated carbon is found to be effective in promoting the production of monocyclic aromatic hydrocarbons (MAHs). Two metallic catalysts, i. e., bentonite and red mud, have strong acidities but quite low surface areas and less porous structures. Therefore, the dehydrated intermediates produced are especially easy to repolymerize to form char or coke without the restriction of obtaining a porous structure during the pyrolysis process. Activated carbon has not only a certain acidity but also a rich porous structure. Lignin fast pyrolysis-derived oxygenates can diffuse and react on the well-dispersed active sites within the pores of activated carbons. The catalytic performance of the activated carbon are supposed to be determined by the pore size. Only pores of similar size to lignin fast pyrolysis-derived oxygenates (0.6-1 nm) seems to be effective for the production of MAHs. Pores larger or smaller than lignin fast pyrolysis-derived oxygenates both tend to cause coke deposition rather than MAHs formation.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2019
Keywords
Low-cost catalysts, Lignin, Fast pyrolysis, Deoxygenation, Dehydration
National Category
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-255169 (URN)10.1016/j.cej.2019.05.125 (DOI)000471682900081 ()2-s2.0-85065989283 (Scopus ID)
Note

QC 20190904

Available from: 2019-09-04 Created: 2019-09-04 Last updated: 2019-09-04Bibliographically approved
Nabeel, M., Alba, M., Karasev, A., Jönsson, P. G. & Dogan, N. (2019). Characterization of Inclusions in 3rd Generation Advanced High-Strength Steels. Metallurgical and materials transactions. B, process metallurgy and materials processing science, 50(4), 1674-1685
Open this publication in new window or tab >>Characterization of Inclusions in 3rd Generation Advanced High-Strength Steels
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2019 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 50, no 4, p. 1674-1685Article in journal (Refereed) Published
Abstract [en]

Samples taken from laboratory-produced 3rd generation advanced high-strength steels, solidified at a low cooling rate, have been investigated to study the characteristics of non-metallic inclusions. Two steels, containing 2 and 5 pct Mn content, were produced for this purpose. A higher number of total inclusions were observed in 5 pct Mn steel. The four main types of inclusions observed were Al2O3, AlN, MnS, and AlSiMn-oxide. These classes were divided into subclasses according to variations in their chemistry. The major subclasses of AlN inclusions are either plate-like or regular in shape and have different size distributions. Thermodynamic calculations suggest that plate-like AlN inclusions are formed at the initial stage of solidification, while faceted/regular-shaped inclusions are precipitated toward the end of solidification. Moreover, it was found that the size of nitride inclusions is related to their N content. This phenomenon is discussed from the viewpoint of nucleation theory.

Place, publisher, year, edition, pages
Springer, 2019
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:kth:diva-255553 (URN)10.1007/s11663-019-01605-0 (DOI)000475698700016 ()2-s2.0-85066623028 (Scopus ID)
Note

QC 20190808

Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-08Bibliographically approved
Nabeel, M., Alba, M., Sun, S., Karasev, A., Jönsson, P. & Dogan, N. (2019). Characterization of inclusions in high-Mn steel using two-dimensional and three-dimensional methods. Iron & Steel Technology, 16(7), 74-82
Open this publication in new window or tab >>Characterization of inclusions in high-Mn steel using two-dimensional and three-dimensional methods
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2019 (English)In: Iron & Steel Technology, ISSN 1547-0423, Vol. 16, no 7, p. 74-82Article in journal (Refereed) Published
Abstract [en]

The characteristics of inclusions in high-manganese steel samples from laboratory-scale experiments were investigated. This was done by two-dimensional and three-dimensional methods. In the two-dimensional investigations, inclusions on polished cross-sections were observed by using automatic scanning electron microscopy analysis. For the three-dimensional investigations, inclusions collected on a film filter after electrolytic extraction were observed. It was found that electrolytic extraction could be successfully applied to high-manganese steels. Further, automatic analysis, which is a common practice in steel industry, has limitations for the detection and classification of nitride inclusions, whereas it was possible to detect nitrides using the three-dimensional method.

Place, publisher, year, edition, pages
Association for Iron & Steel Technology, 2019
Keywords
Extraction, Nitrides, Scanning electron microscopy, Steelmaking, Automatic analysis, Automatic scanning, Electrolytic extraction, High manganese steel, High Mn steels, Three-dimensional method, Manganese steel
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-262456 (URN)2-s2.0-85069550030 (Scopus ID)
Note

QC 20191018

Available from: 2019-10-18 Created: 2019-10-18 Last updated: 2019-10-18
Zaini, I. N., Lopez, C. G., Pretz, T., Yang, W. & Jönsson, P. (2019). Characterization of pyrolysis products of high-ash excavated-waste and its char gasification reactivity and kinetics under a steam atmosphere. Waste Management, 97, 149-163
Open this publication in new window or tab >>Characterization of pyrolysis products of high-ash excavated-waste and its char gasification reactivity and kinetics under a steam atmosphere
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2019 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 97, p. 149-163Article in journal (Refereed) Published
Abstract [en]

The focus of this study is the pyrolysis and gasification of Refuse Derived Fuel (RDF) and fine fractions recovered from the excavation of landfill waste, with an emphasize on the characterization of the reactivity and kinetics of the char-steam gasification. The results from the pyrolysis tests demonstrated that CO and CO2 are the main produced gases during the pyrolysis of the finer fraction of landfill waste. This might be caused by the accumulation of degraded organic materials. The oil products from the pyrolysis of landfill waste were dominated by the derivative products of plastics such as styrene, toluene, and ethylbenzene. The chars obtained from the pyrolysis process were gasified under steam and steam/air atmospheres at temperatures between 800 and 900 degrees C by using thermogravimetry. The results from the gasification tests demonstrated that the char reactivity was mainly affected by the amount ratio between catalytic elements (K, Ca, Na, Mg, and Fe) over the inhibitor elements (Si, Al, and Cl), as well as the ash amount in the char. The results showed that char from the fine fraction of landfill waste has a higher reactivity than the RDF fraction, due to the high content of catalytic metal elements. These results suggest the use of a smaller sieve opening size for landfill waste separation processes may produce waste fuels with a high reactivity during gasification. Further, based on the thermogravimetric data, the kinetic parameters of landfill waste char gasification were calculated to have activation energies ranging from 54 to 128 kJ/mol. Author(s). Published by Elsevier Ltd.

Place, publisher, year, edition, pages
PERGAMON-ELSEVIER SCIENCE LTD, 2019
Keywords
Steam gasification, RDF, Municipal solid waste, Thermogravimetry analysis, Landfill mining
National Category
Environmental Sciences
Identifiers
urn:nbn:se:kth:diva-261025 (URN)10.1016/j.wasman.2019.08.001 (DOI)000485213500018 ()31447022 (PubMedID)2-s2.0-85070414215 (Scopus ID)
Note

QC 20191002

Available from: 2019-10-02 Created: 2019-10-02 Last updated: 2019-10-02Bibliographically approved
Liu, Y., Ersson, M., Liu, H., Jönsson, P. & Gan, Y. (2019). Comparison of Euler-Euler Approach and Euler–Lagrange Approach to Model Gas Injection in a Ladle. Steel Research International, 90(5), Article ID 1800494.
Open this publication in new window or tab >>Comparison of Euler-Euler Approach and Euler–Lagrange Approach to Model Gas Injection in a Ladle
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2019 (English)In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344X, Vol. 90, no 5, article id 1800494Article in journal (Refereed) Published
Abstract [en]

The gas injection in a ladle using a porous plug is simulated using both the Euler-Euler and Euler-Lagrange approaches. The effects of various forces, bubble sizes, and bubble injection frequencies on the flow pattern are modeled. For predicting axial velocity and turbulent kinetic energy, the Euler-Lagrange approach fits better than Euler-Euler approach with the measured data. In the Euler-Euler approach, differences in axial velocities and turbulent kinetic energies for various bubble sizes mainly appears in the plume zone. In the Euler-Lagrange approach, different bubble sizes with the same injection frequency have a small impact on the turbulence dissipation. Furthermore, the turbulent dispersion from the gas phase to the liquid phase has an important effect on the plume structure and spout eye formation. For both modeling, the smaller the bubble diameter is, the larger the axial velocity and turbulent kinetic dissipation are in the central zone. For the bubble coalescence and breakup, according to the comparison of two modeling approaches, the Euler-Lagrange approach is more accurate in predicting the flow pattern for gas injection with a porous plug in the ladle.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2019
Keywords
bubble coalescence and breakup, ladle, mathematical modeling, porous plug, Coalescence, Computational fluid dynamics, Flow patterns, Kinetics, Ladles, Lagrange multipliers, Mathematical models, Turbulent flow, Bubble coalescence, Euler-Euler approach, Injection frequencies, Lagrange approach, Turbulence dissipation, Turbulent dispersion, Turbulent kinetic energy, Kinetic energy
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-252488 (URN)10.1002/srin.201800494 (DOI)000477083800005 ()2-s2.0-85062368543 (Scopus ID)
Note

QC 20190712

Available from: 2019-07-12 Created: 2019-07-12 Last updated: 2019-09-17Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-9775-0382

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