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Lennartsson, AndreasORCID iD iconorcid.org/0000-0002-6655-0684
Publications (10 of 18) Show all publications
Ahmed, H., Sideris, D., Lennartsson, A., Prasad, P. N., Sundqvist Ökvist, L., From, L.-E., . . . Björkman, B. (2020). Effect of the Ash from H2‐Rich Carbonaceous Materials on the Physicochemical Properties of Raceway Slag and Coke Reactivity. Steel Research International
Open this publication in new window or tab >>Effect of the Ash from H2‐Rich Carbonaceous Materials on the Physicochemical Properties of Raceway Slag and Coke Reactivity
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2020 (English)In: Steel Research International, ISSN 1611-3683, E-ISSN 1869-344XArticle in journal (Refereed) Accepted
Abstract [en]

The iron and steel industry is one of the most important sectors worldwide, and it has a great impact on the global economy; however, this sector is still highly dependent on fossil carbon. To decrease this dependency, approaches to partially replace the injected pulverized coal with secondary, highly reactive, renewable (biomass) and H2‐rich materials have been studied. The injection of such materials is expected to significantly decrease the emitted CO2 from blast furnaces. However, due to the different ash composition of these alternative materials (especially alkali and alkaline earth metals) compared to that of ordinary injected coal, these materials are expected to alter the raceway slag properties and affect the coke reactivity. In the present article, the effect of the ash from different hydrogen‐rich carbonaceous materials on the raceway slag physicochemical properties as well as coke reactivity is reported. The melting characteristics of the ash briquettes in contact with the coke and wettability of the melted ash on the coke surface are determined visually using an optical heating microscope. The effect of the ash on the coke reactivity is studied by means of thermogravimetry under a continuous flow of CO2.

Place, publisher, year, edition, pages
John Wiley & Sons, 2020
Keywords
biomass, blast furnace, injection, iron making, plastic
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-79179 (URN)10.1002/srin.202000098 (DOI)
Available from: 2020-06-04 Created: 2020-06-04 Last updated: 2020-06-04
Strandkvist, I., Pålsson, K., Andersson, A., Olofsson, J., Lennartsson, A., Samuelsson, C. & Engström, F. (2020). Minimizing Chromium Leaching from Low-Alloy Electric Arc Furnace (EAF) Slag by Adjusting the Basicity and Cooling Rate to Control Brownmillerite Formation. Applied Sciences, 10(1), 35-50, Article ID 35.
Open this publication in new window or tab >>Minimizing Chromium Leaching from Low-Alloy Electric Arc Furnace (EAF) Slag by Adjusting the Basicity and Cooling Rate to Control Brownmillerite Formation
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2020 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 10, no 1, p. 35-50, article id 35Article in journal (Refereed) Published
Abstract [en]

Brownmillerite is connected to chromium leaching when present in steel slags. To prevent chromium leaching, brownmillerite in slag should be prevented. Two methods for decreasing brownmillerite content in low-alloy electric arc furnace (EAF) slag were investigated: decreasing the basicity and increasing the cooling rate. The methods were tried on both laboratory scale and in full-scale production. In the laboratory scale experiments, chromium leaching decreased as the basicity decreased until brownmillerite was no longer present, slower cooling resulted in increased chromium leaching, and faster cooling decreased chromium leaching. In full-scale production, basicity modified single batches, with a basicity below 2.2, generally leached less chromium than slag batches with higher basicity, thus verifying the correlation between basicity and chromium leaching seen in laboratory scale experiments. The cooling process in the full-scale experiments was achieved either by letting the slag cool by itself in the air or by water spraying. The water-sprayed slag, which cooled faster, had less chromium leaching than the air-cooled slag. The full-scale production experiments confirmed that both decreasing basicity below 2.2 and increasing the rate of cooling could be used to decrease chromium leaching.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
EAF slag, chromium, leaching, brownmillerite, laboratory scale, full scale
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-77396 (URN)10.3390/app10010035 (DOI)000509398900035 ()2-s2.0-85078897464 (Scopus ID)
Note

Validerad;2020;Nivå 2;2020-01-31 (johcin)

Available from: 2020-01-14 Created: 2020-01-14 Last updated: 2020-04-22Bibliographically approved
Lotfian, S., Vikström, T., Lennartsson, A., Björkman, B., Ahmed, H. & Samuelsson, C. (2019). Evaluating the potential of plastic-containing materials as alternative reducing agents. Canadian metallurgical quarterly, 58(4), 389-399
Open this publication in new window or tab >>Evaluating the potential of plastic-containing materials as alternative reducing agents
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2019 (English)In: Canadian metallurgical quarterly, ISSN 0008-4433, E-ISSN 1879-1395, Vol. 58, no 4, p. 389-399Article in journal (Refereed) Published
Abstract [en]

The amount of discarded plastic-containing materials is increasing, and one option to help with this issue is to use these materials in bath smelting processes. The injection of plastic-containing materials to partially substitute coal in zinc-fuming processes has been studied in an industrial trial at Boliden–Rönnskär smelter. To evaluate the potential of plastic-containing materials, thermodynamic calculations were performed in this study. In the first step, a thermodynamic calculation was performed for trials with only coal injection, and then this calculation was applied to trials with the co-injection of plastic materials. The thermodynamic calculation shows that not all the injected coal participates in the reactions within the slag. Similarly, the calculation with the co-injection of plastic-containing materials shows that different amounts of each plastic material participate in the reactions within the slag bath.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
base metal production, industrial trial, recycling, reducing agent, Shredder residue material, sustainable management, thermodynamic calculation
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-73373 (URN)10.1080/00084433.2019.1590044 (DOI)000463333600001 ()
Note

Validerad;2019;Nivå 2;2019-10-10 (johcin)

Available from: 2019-04-01 Created: 2019-04-01 Last updated: 2019-10-10Bibliographically approved
Lotfian, S., Vikström, T., Lennartsson, A., Björkman, B., Ahmed, H. & Samuelsson, C. (2019). Plastic-containing materials as alternative reductants for base metal production. Canadian metallurgical quarterly, 58(2), 164-176
Open this publication in new window or tab >>Plastic-containing materials as alternative reductants for base metal production
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2019 (English)In: Canadian metallurgical quarterly, ISSN 0008-4433, E-ISSN 1879-1395, Vol. 58, no 2, p. 164-176Article in journal (Refereed) Published
Abstract [en]

Shredder residue materials are produced after the removal of ferrous and non-ferrous fractions from end-of-life electronic equipment. Despite the high plastic content and metal value in the ash, high percentages of these materials are currently sent to landfills. In this study, the potential of utilising shredder residue material and other plastic-containing materials as reducing agents was studied. Plastic-containing materials were co-injected with coal into a zinc-fuming furnace in Boliden-Rönnskär smelter. The data obtained from the trial, such as the data from the chemical analysis of the slag and the steam production, are discussed. The observations indicate that plastic-containing material can replace up to 1 ton h−1 of coal without a significant decrease in the zinc reduction rate.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Shredder residue material, reducing agent, sustainable, base metal production, zinc-fuming, industrial trial, recycling, plastic-containing materials, slag
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-73665 (URN)10.1080/00084433.2018.1532951 (DOI)000466443300005 ()2-s2.0-85063106067 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-17 (johcin)

Available from: 2019-04-15 Created: 2019-04-15 Last updated: 2019-06-17Bibliographically approved
Lotfian, S., Lennartsson, A. & Jokilaakso, A. (2019). Sustainable Management of the Plastic-Rich Fraction of WEEE by Utilization as a Reducing Agent in Metallurgical Processes. Applied Sciences, 9(20), Article ID 4224.
Open this publication in new window or tab >>Sustainable Management of the Plastic-Rich Fraction of WEEE by Utilization as a Reducing Agent in Metallurgical Processes
2019 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 9, no 20, article id 4224Article in journal (Refereed) Published
Abstract [en]

In modern society, there is a fast growth in the production of electrical and electronic equipment (EEE); however, rapid growth results in the frequent discarding of this equipment. During the treatment of discarded materials, a stream is generated that contains a high fraction of plastic materials, but also metals and oxides. This stream, which is called shredder residue material (SRM), is heterogeneous, which limits its recycling options. Utilizing this material in metallurgical processes allows the plastic fraction to be used as a reductant and energy source and the metallic fraction to be recycled and returned to the production of EEE. The aim of this study was to evaluate the potential of plastic-containing materials, especially SRM, as alternative reductants in metallurgical processes. The first step was to compare the thermal conversion characteristics of plastic-containing materials to the currently used reducing agent, i.e., coal. Three main candidates, polyurethane (PUR), polyethylene (PE), and SRM, were studied using a drop tube furnace and an optical single-particle burner. PE had the highest volatile content and the fastest conversion time, whereas PUR had the longest conversion time. Thereafter, plastic materials were tested at the industrial scale through injection to the zinc fuming process at the Boliden Rönnskär smelter. During the industrial trial, the amount of coal that was injected was reduced and substituted with plastic material. The results indicate the possibility of reducing the coal injection rate in favor of partial substitution with plastic materials.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
shredder residue material, plastic, metallurgical process, sustainable management, conversion characteristics
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-76198 (URN)10.3390/app9204224 (DOI)000496269400027 ()
Note

Validerad;2019;Nivå 2;2019-10-16 (johcin)

Available from: 2019-10-10 Created: 2019-10-10 Last updated: 2019-11-29Bibliographically approved
Lennartsson, A., Engström, F., Björkman, B. & Samuelsson, C. (2019). Understanding the bottom buildup in an electric copper smelting furnace by thermodynamic calculations. Canadian metallurgical quarterly, 58(1), 89-95
Open this publication in new window or tab >>Understanding the bottom buildup in an electric copper smelting furnace by thermodynamic calculations
2019 (English)In: Canadian metallurgical quarterly, ISSN 0008-4433, E-ISSN 1879-1395, Vol. 58, no 1, p. 89-95Article in journal (Refereed) Published
Abstract [en]

Thermodynamic calculations were used to investigate the liquidus temperature of the slag and the possible influence on the buildup formation in an electric copper smelting furnace. The impact of parameters such as Fe/SiO2 ratio, partial pressure of oxygen and the content of the oxides ZnO, Al2O3 and Cr2O3 in the slag were investigated with respect to the liquidus temperature of the slag. Results show that the chromium content in the slag has the greatest impact on the liquidus temperature and on the formation of solid particles. The characterization of the buildup done earlier showed that spinel phases were among the dominating phases. This is supported by the thermodynamic calculations in the present paper, where the chromite solid solution was found to be the primary precipitation phase.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2019
Keywords
Copper smelting, FactSage, Buildup, Thermodynamic calculation, Spinel, Pyrometallurgy, Electric furnace
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-70765 (URN)10.1080/00084433.2018.1518804 (DOI)000452743200008 ()2-s2.0-85053228724 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-01-30 (inah)

Available from: 2018-09-05 Created: 2018-09-05 Last updated: 2019-01-30Bibliographically approved
Sefidari, H., Lindblom, B., Wiinikka, H., Nordin, L. O., Lennartsson, A., Mouzon, J., . . . Öhman, M. (2018). The effect of disintegrated iron-ore pellet dust on deposit formation in a pilot-scale pulverized coal combustion furnace: Part II: Thermochemical equilibrium calculations and viscosity estimations. Fuel processing technology, 180, 189-206
Open this publication in new window or tab >>The effect of disintegrated iron-ore pellet dust on deposit formation in a pilot-scale pulverized coal combustion furnace: Part II: Thermochemical equilibrium calculations and viscosity estimations
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2018 (English)In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 180, p. 189-206Article in journal (Refereed) Published
Abstract [en]

Fly ash particles from the combustion of solid-fuels together with disintegrated particles arising from iron-ore pellets result in accumulation of deposits on the refractory linings of the grate-kiln induration machine during the iron-ore pelletizing process. The deposits amass in the high-temperature regions of the induration furnace thus disturbing the flow of gas and pellets. Therefore, to tackle the above-mentioned issues, an understanding of deposit formation mechanism is of crucial importance. This study was conducted with the objective of addressing the effect of disintegrated iron-ore pellet dust on deposit formation and the mechanisms behind deposition (slagging) in the grate-kiln process. A comprehensive set of experiments was conducted in a 0.4 MW pilot-scale pulverized-coal- fired furnace where three different scenarios were considered as follows; Case 1 (reference case): Coal was combusted without the presence of pellet dust. Case 2: Natural gas was combusted together with simultaneous addition of pellet dust to the gas stream. Case 3: Coal was combusted together with the addition of pellet dust simulating the situation in the large-scale setup. Fly ash particles and short-term deposits were characterized and deposition was addressed in Part I of this study. In light of the experimental observations (Part I) and the thermochemical equilibrium calculations (Part II), a scheme of ash transformation during the iron-ore pelletizing process was proposed. The dissolution of hematite particles into the Ca-rich-aluminosilicate melt (from the coal-ash constituents) decreased the viscosity and resulted in the formation of stronger (heavily sintered) deposits. Overall, this pilot-scale work forms part of a wider study which aims at deepening the understanding of ash transformation phenomena during the large-scale pelletizing process.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Energy Engineering Chemical Engineering Metallurgy and Metallic Materials Chemical Process Engineering
Research subject
Energy Engineering; Chemical Technology; Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-69019 (URN)10.1016/j.fuproc.2018.05.005 (DOI)000447580600020 ()2-s2.0-85047214684 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-11-05 (johcin) 

Available from: 2018-05-31 Created: 2018-05-31 Last updated: 2019-01-18Bibliographically approved
Lennartsson, A. (2017). Application of FactSage in Education within Process Metallurgy at Luleå University of Technology. In: : . Paper presented at GTT Annual Workshop 2017, Herzogenrath-Kohlscheid, Germany, 28-30 June 2017.
Open this publication in new window or tab >>Application of FactSage in Education within Process Metallurgy at Luleå University of Technology
2017 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Luleå University of Technology are educating engineers, teachers nurses etc. The research subject Process Metallurgy is involved in the education of engineers within the MSc program Sustainable Process Engineering and especially the focus area called Sustainable Minerals and Metals Processing.

FactSage is used in the education to introduce the possibilities, advantages and disadvantages with computational thermochemistry. To do this, the different FactSage modules are introduced in different courses both during lab-sessions and as a supplement to practical projects.

This presentation will give some examples on how FactSage and computational thermochemistry is taught within the program.

Keywords
Teaching, FactSage
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-64745 (URN)
Conference
GTT Annual Workshop 2017, Herzogenrath-Kohlscheid, Germany, 28-30 June 2017
Available from: 2017-07-03 Created: 2017-07-03 Last updated: 2018-01-12Bibliographically approved
Lennartsson, A., Engström, F., Björkman, B. & Samuelsson, C. (2015). Characterisation of buildup in an electric furnace for smelting copper concentrate (ed.). Paper presented at . Canadian metallurgical quarterly, 54(4), 477-484
Open this publication in new window or tab >>Characterisation of buildup in an electric furnace for smelting copper concentrate
2015 (English)In: Canadian metallurgical quarterly, ISSN 0008-4433, E-ISSN 1879-1395, Vol. 54, no 4, p. 477-484Article in journal (Refereed) Published
Abstract [en]

The results from a characterization of buildup in an electric smelting furnace for treating copper-rich feed material at the Boliden Rönnskär smelter in Sweden are presented. The aim of the work was to obtain better knowledge about the mechanisms behind the formation of the buildup. Samples from the buildup were taken during the rebuilding of the furnace. The samples were characterized using chemical and mineralogical techniques. The buildup consists mainly of different phases such as spinel, matte, olivine and metalloids and has a complex and varying mineralogy, which indicates that the buildup is not formed under equilibrium conditions.

Keywords
copper smelting, electric furnace, characterization, buildup, mineralogy, Chemical engineering - Metallurgical process and manufacturing engineering, Kemiteknik - Metallurgisk process- och produktionsteknik
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-12629 (URN)10.1179/1879139515Y.0000000026 (DOI)000371430800013 ()2-s2.0-84960942161 (Scopus ID)bcac5a58-5290-4eaf-909b-6c9e9fae58f6 (Local ID)bcac5a58-5290-4eaf-909b-6c9e9fae58f6 (Archive number)bcac5a58-5290-4eaf-909b-6c9e9fae58f6 (OAI)
Note
Validerad; 2016; Nivå 2; 20150629 (lenann)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Lennartsson, A. (2015). Wise Process Routes for Varying Feedstock in Base Metal Extraction: Modelling of a Peirce-Smith Converter and Investigation of Buildup Formation in an Electric Smelting Furnace (ed.). (Doctoral dissertation). Paper presented at .
Open this publication in new window or tab >>Wise Process Routes for Varying Feedstock in Base Metal Extraction: Modelling of a Peirce-Smith Converter and Investigation of Buildup Formation in an Electric Smelting Furnace
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Kloka processvägar för varierande råmaterial vid utvinning av basmetaller
Abstract [en]

Copper, like silver and gold, is one of the metals that are known to have been worked by some of the oldest civilisations on record. It is used forits unique properties such as corrosion resistance, good workability, high thermal conductivity and attractive appearance. New mines are opened to maintain a supply of primary feedstock for copper smelters. These new deposits are in many instances found to have a more complex mineralogy with several minor elements. Besides treating primary material, copper smelters are also showing an increasing interest in treating secondary materials, such as copper containing scrap from waste electrical and electronic equipment, which also have a complex composition. This increased complexity of the raw material can potentially lead to smelter plants having to deal with a feedstock containing several minor elements, including antimony, arsenic, bismuth, gold, silver, etc., at levels that can influence the ability to, in a cost effective way, maintain the final grade of the copper cathode. Process simulations can be an important tool for understanding the impact of process parameters on product quality and for the purpose of process optimisation. In the present work a dynamic, non-equilibrium model based on thermodynamics over the Peirce-Smith converter has been developed. The model was found to predict the composition of the main condensed phases well. Thermodynamic calculations in combination with characterisation have also been used to understand the buildup in an electric smelting furnace. Results from the characterisation and the modelling showed that the buildup consists mainly of different phases such as spinel, matte, olivine and metalloids and has a complex and varying mineralogy, which indicates that the buildup is not formed under equilibrium conditions. During the modelling the impact of parameters such as Fe/SiO2ratio, partial pressure of oxygen and the content of the oxides ZnO, Al 4O3 and Cr2O3 in the slag were investigated with respect to the liquidus temperature of the slag. The modelling showed that the chromium content in the slag has the greatest impact on the liquidus temperature and on the formation of solid particles. The thermodynamic modelling supports the result from the characterisation.The combination of characterisation, thermodynami-based modelling and process knowledge gives further understanding of element distribution. This enhances the potential to adjust for variations in raw material feed and flexible process routes.

Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Keywords
Chemical engineering - Metallurgical process and manufacturing engineering, Kemiteknik - Metallurgisk process- och produktionsteknik
National Category
Metallurgy and Metallic Materials
Research subject
Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-17691 (URN)4b186303-bf34-43a2-b1b9-3a5d1dd78e62 (Local ID)978-91-7583-401-6 (ISBN)978-91-7583-402-3 (ISBN)4b186303-bf34-43a2-b1b9-3a5d1dd78e62 (Archive number)4b186303-bf34-43a2-b1b9-3a5d1dd78e62 (OAI)
Note
Godkänd; 2015; 20150826 (lenann); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Andreas Lennartsson Ämne: Processmetallurgi/Process Metallurgy Avhandling: Wise Process Routes for Varying Feedstock in Base Metal Extraction Opponent: Professor Pekka Taskinen, Department of Materials Science and Engineering, Aalto University, Helsingfors, Finland. Ordförande: Biträdande professor Caisa Samuelsson, Avd för mineralteknik och metallurgi, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet, Luleå. Tid: Fredag 30 oktober, 2015 kl 10.00 Plats: F531, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-01-12Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6655-0684

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