Fiseha Tesfaye

Fiseha Tesfaye
Metso Outotec · Process Design | Smelting Technologies

Doctor of Engineering

About

103
Publications
38,234
Reads
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456
Citations
Introduction
Fiseha Tesfaye is a Docent (Adj. Prof.) and Senior Researcher in the Johan Gadolin Process Chemistry Centre of Åbo Akademi University. Dr. Tesfaye does research in Extractive Metallurgy, Circular Economy of Materials, Recycling, Materials Science, and Chemical Engineering. His current projects are "Thermodynamic investigation of complex inorganic material systems for improved renewable energy and metals production processes," and "Circular economy in the metal & energy industries."
Additional affiliations
November 2019 - present
Åbo Akademi University
Position
  • Adjunct Professor
September 2018 - February 2022
Åbo Akademi University
Position
  • Senior Researcher
March 2018 - August 2018
Seoul National University
Position
  • Researcher
Education
January 2010 - August 2014
Aalto University
Field of study
  • Metallurgy
September 2002 - September 2009
Helsinki University of Technology
Field of study
  • Materials Processing Technology

Publications

Publications (103)
Article
Full-text available
In this study, we tested several amino acids as eco-friendly inhibitors against corrosion of mild steel by used cooking oils (UCOs). The corrosion inhibition was studied by immersing mild steel rods in the UCOs and reference fresh rapeseed and olive oils mixed with amino acids. The immersion tests were conducted at room temperature for three days....
Presentation
Full-text available
The role of Cu-based phases in combustion processes has boldly emerged with the drastic increase in the waste combustion, sparking the need to update thermodynamic databases for a better understanding and control. In the present work, we have reviewed the content and sources of Cu in selected biomass fuels and ashes, and examined the mechanisms thr...
Chapter
Phase equilibria of the Ag–Ge–Bi–Te system in the part GeTe–Ag8GeTe6–Te–Bi2Te3 (I) were established by the electromotive force (EMF) method with a solid Ag+ conducting electrolyte. It was shown that the concentration space of (I) in the part 4GeTe∙Bi2Te3–Ag8GeTe6–Te–Bi2Te consists of 8 four-phase regions, formed of the layered compounds of the nGeT...
Book
Full-text available
The reliance on fossil fuels for energy is unsustainable and has released an unprecedented amount of carbon dioxide into our atmosphere. The continual research and development effort into clean and sustainable energy technologies is of paramount importance to ensure the responsible progress of human civilization and innovations. This symposium, wit...
Article
Full-text available
Thermal stabilities of selected ternary phases of industrial interest in the Ag-Cu-S system have been studied by the calorimetric and electromotive force techniques. The ternary compounds Ag1.2Cu0.8S (mineral mackinstryite) and AgCuS (mineral stromeyerite) were equilibrated through high-temperature reaction of the pure Cu2S and Ag₂S in an inert atm...
Article
Full-text available
Used cooking oils (UCOs) have a high potential as renewable fuels for the maritime shipping industry. However, their corrosiveness during storage and usage are some of the concerns yet to be investigated for addressing compatibility issues. Thus, the corrosion of steels and copper exposed to the UCOs was studied through the immersion of metal rods...
Article
Full-text available
Urban areas are at the forefront of future sources of the technology metals. Urban mining involves collection and management of spent products and preprocessing and recovery of valuable materials. Recently, some cities in Europe signed the EU Green City Accord, an initiative to make cities greener, cleaner, and healthier. Technological developments...
Chapter
The role of Cu-based phases in combustion processes has boldly emerged with the drastic increase in the waste combustion, sparking the need to update thermodynamic databases for a better understanding and control. In the present work, we have reviewed the content and sources of Cu in selected biomass fuels and ashes, and examined the mechanisms thr...
Article
Full-text available
Developing technologies essential to the transition towards a decarbonized energy future require discovery of new energy materials with unique properties and wider thermal and chemical stability ranges. To facilitate this discovery, comprehensive databases of inorganic materials critical to advanced clean energy technologies need to be developed. R...
Article
Discoveries of new energy materials with unique properties and wider thermal stability ranges enable sustainable developments toward a low-carbon society. In this work, phase stabilities and thermodynamic properties of selected compounds in the Ag-Te-Cl system with potential application as energy materials have been critically reviewed and experime...
Article
Full-text available
The two conventional metallurgical processing routes for metals extraction from primary resources (mining) and recovery from secondary resources (urban mining and industrial side streams) are pyrometallurgy and hydrometallurgy. A third route combines pyro- and hydro-metallurgical processes in a unique way to exploit strengths of the two approaches....
Article
Full-text available
Equilibrium phase formations below 600 K in the parts Ag2Te–FeTe2–F1.12Te–Ag2Te and Ag8GeTe6–GeTe–FeTe2–AgFeTe2–Ag8GeTe6 of the Fe–Ag–Ge–Te system were established by the electromotive force (EMF) method. The positions of 3- and 4-phase regions relative to the composition of silver were applied to express the potential reactions involving the AgFeT...
Book
In this volume, operators, engineers, and researchers present information about all aspects of current processing technologies for nickel and cobalt, as well as emerging technologies for both metals. Contributions from industry and academia encompass metallurgical aspects of metals commonly associated with nickel and cobalt, such as copper and plat...
Chapter
The equilibrium phase space of the Ag–Fe–X–Se (X: Ge, Sn) systems in the parts Ag8XSe6–XSe–FeSe2–AgFeSe2–Ag8XSe6 consists of four quaternary-phase regions formed with the participation of low-temperature modifications of the Ag2FeGeSe4 and Ag2FeSnSe4 compounds. The kinetic barriers of the formation of equilibrium four-phase regions that are observe...
Book
This volume covers various aspects of the fundamentals, synthesis, analysis, design, monitoring, and control of metals, materials, and metallurgical processes and phenomena. Topics represented include but are not limited to: (1) Experimental, analytical, physical, and computer modeling of physical chemistry and thermodynamics, (2) Modeling of the...
Article
Full-text available
Today, various smelting processes incorporate the processing of secondary resources, such as waste electrical and electronic equipment (e-waste). The increasing amount and complexity of e-waste introduces new and additional valuable metals into conventional smelting circuits. For the most efficient recovery of these valuable metals—and to define op...
Article
Full-text available
Based on the literature data on the phase formation of the Ag–Te–Br system in the part AgBr–Ag2Te–Te (I) and the results of the electromotive force (EMF) measurements of the electrochemical cells (ECCs) the alleged scheme division of (I) into 10 three-phase regions was analyzed. The overall potential-forming reactions were expressed for the phase r...
Article
Full-text available
Rhenium is a scarce and highly important metal, which is widely used in high-temperature superalloys and platinum-rhenium catalysts due to its unique physicochemical properties. The substitution of rhenium in its applications is very limited, and there is no suitable substitute without losing essential performance. Furthermore , global extractable...
Article
Full-text available
Waste fish oils (FOs) and used cooking vegetable oils (UCOs) are increasingly becoming alternative renewable fuels. However, different physicochemical aspects of these renewable fuels, including the effect of storage, are not well-known. In this work, the effect of the storage period on physicochemical properties of selected samples of FOs and UCOs...
Article
Full-text available
Rare earth metals (REMs), classified as critical materials by the high-tech economies, are used in a variety of applications including catalysts, permanent magnets, phosphors etc. REMs used in different parts of electric vehicles (EVs) and smartphones are predominantly lanthanides. Manufacturing of an EV consumes over 15 kg of REMs in different par...
Article
Full-text available
Besides the widely applied hydropower, wind farms and solar energy, biomass and municipal and industrial waste are increasingly becoming important sources of renewable energy. Nevertheless, fouling, slagging and corrosion associated with the combustion processes of these renewable sources are costly and threaten the long-term operation of power pla...
Article
Full-text available
Cadmium sulfide (CdS) nanocrystals were produced by the electrolytic method in a glass electrolyzer with cadmium electrodes. Solutions of sodium thiosulfate (Na2S2O3), sodium sulfite (Na2SO3) and sodium sulfide (Na2S) in distilled water were used as electrolytes. It was determined that the composition of the obtained phases depends on the electroly...
Article
Full-text available
Demand for nonferrous metals continues to increase globally, as they are essential in a variety of high-tech applications, including in the renewable energy sector. For example, European manufacturing capacity for Li-ion batteries, which require a substantial amount of metals such as Ni and Co, is expected to grow by more than 15 times the current...
Data
Appendix A. Supplementary data to the article: Solid-state electrochemical synthesis and thermodynamic properties of selected compounds in the Ag–Fe–Pb–Se system
Article
Free full-text access at: (https://authors.elsevier.com/c/1bNIp4c3MLnU5x) The AgFeSe2 and Ag2FePbSe4 compounds within the phase region Ag2Se–PbSe–Se–FeSe0.96–Ag2Se (I) of the Ag–Fe–Pb–Se system were obtained from the melt. Their annealing at T < 600 K lead to the decomposition into binary phases of the Ag–Se, Pb–Se, and Fe–Se systems. The metastabl...
Article
Full-text available
The conventional non-ferrous metals production processes were developed when scarcity of natural resources and environmental impacts were not issues. Currently, there are efforts underway for advancing sustainable metallurgical processes that enable resource efficiency. The recent increase in the non-ferrous metals demand, complexities of the avail...
Article
Free full-text access link: (https://authors.elsevier.com/c/1bBE63A~K2YmVt) Abstract: The advancement in technology has resulted in the development of newer and improved electrical products. The older products are becoming obsolete and are discarded as waste at a continuously increasing trend. Printed circuit board (PCB) is the main focus of elect...
Article
Full-text available
Recently, awareness has been raised concerning the need to decrease the total environmental footprint throughout the life cycle of a medicine, including the packaging materials. Aluminum, a highly energy-intensive metal, is widely used in blister packages together with polymers. However, these blister packages suffer from poor recyclability, with t...
Article
Full-text available
Today, a reliable supply of certain metals including the minor metals that are used in small quantities for a variety of economically significant applications (e.g., smart phones, laptops, solar cells, electric vehicles, etc.) and national defense applications are at risk. To address this challenge of metals supply risk, the European Commission in...
Chapter
The phase equilibria of the Ag–Ge–Sb–Te system in the part Ag8GeTe6–Ge–GeTe–Sb2Te3 were investigated by the electromotive force (EMF) method. The determined phase relations were used to express the chemical reactions. The potential-forming reactions were performed by applying electrochemical cells (−) C | Ag | Ag2GeS3-glass | D | C (+), where C is...
Article
Full-text available
The corrosion behavior of three used cooking oils and one non-edible fish oil was experimentally investigated by the immersion test of iron rods at room temperature. The corrosivity of the tested oils was indirectly determined from the amount of the dissolved iron in the tested oils after the immersion test. Different factors that affect the corros...
Book
This volume includes contributions on the physical and numerical modeling of materials processing, and covers a range of metals and minerals. Authors present models and results related to the basics of processing such as extraction, joining, separation, and casting. The corresponding fundamentals of mass and heat transport as well as physical and t...
Chapter
Full-text available
The electromotive force (EMF) method was described and some characteristic examples from the past and recent literature were reviewed. The important experimental procedures for a successful measurement of an EMF of different galvanic cells at a certain temperature, and determination of the thermodynamic properties of chemical compounds from the obt...
Article
Full-text available
Environmental concerns and the need for energy savings are presently the most important drivers of research in extractive metallurgy. Recycling fits into this general picture: not only the re-processing of post-consumer products, but also various improvements in a flowsheet that send intermediate products and residues back as feed-stock to a proces...
Book
Every sector faces unique challenges in the transition to sustainability. Across each, materials will play a key role. That will depend on novel materials and processes, but these will only be effective with a solid understanding of the trends in the market. For each respective sector, the papers in this collection will explore the trends and drive...
Article
Full-text available
The possibility of obtaining nanocrystals of the solid solution of zinc and cadmium sulfides by electrolytic method was investigated. Sodium thiosulfate solution in distilled water was used as an electrolyte. It was shown that the composition of the synthesized nanocrystals depends on the electrodes that served as sources of cadmium and zinc ions....
Chapter
Several recent studies have shown the potential of oxy-fuel combustion to reduce NOx(gas) and SO2(gas) emissions. However, the mechanisms through which SO2(gas) reduction takes place has yet to be fully understood. Therefore, development of oxy-sulfate thermodynamic database for a better understanding and control of SO2(gas) emission during oxy-fue...
Chapter
Lithium-ion batteries are already playing a key role in the move from fossil fuels towards clean and renewable energy systems. This is because variabilities in renewable energy grids need to be supported by very stable storage mechanisms (batteries). In electric vehicles, lithium-ion batteries are also very important and determine applicability on...
Chapter
Phase equilibria in the ZnS-Ag2GeS3-Ge-GeS2 part of the Ag-Zn-Ge-S system were investigated using differential thermal analysis, X-ray diffraction, and EMF methods. The data was used to model Ag2GeS3-ZnS polythermal section. Further, the mechanism of formation and thermal stability of the Ag2ZnGeS4 compound were established. The results suggest pre...
Article
Oxidation roasting of sulfide ores and concentrates, which commonly incorporate considerable amounts of sulfosalts, is useful pre-treatment process in the production of metals, chemicals and energy. In this process, feedstocks are oxidized with air in the temperature range from 873 to 1273 K, and a calcine typically with low-residual sulfur and SO2(...
Article
The polythermal sections in the vicinity of the quaternary compounds Ag2FeSnS4 and Ag2FeSn3S8 were modeled. The mechanism of formations of these quaternary compounds and their thermal stabilities have been investigated. The measurements of electromotive force have allowed calculations of the standard thermodynamic functions ΔG, ΔH, and S of the Ag2...
Article
Full free download text at: ( https://authors.elsevier.com/a/1Wxao1IvWPrbxg ) Due to their high corrosion resistance and thermal stability, Cu-Ni-alloys have essential role in many materials engineering applications. Lead is an alloying element in these alloys although it may also be considered as an impurity in certain cases. In copper rich allo...
Article
Full-text available
Thermoelectricity has a strong scientific and technological interest due to its wide application ranging from clean energy producing to photon sensing devices. Recent developments in theoretical studies on the thermoelectric (TE) effects as well as the newly discovered thermoelectric materials provide new opportunities for several applications. Tho...
Conference Paper
Today, aside from the solar, wind and hydro power, solid biomass, municipal solid wastes and industrial wastes are increasingly becoming important sources of renewable energy. However, fouling, slagging and corrosion that are associated with the combustion processes of these renewable resources threaten long-term operation availability and costs of...
Article
Full-text available
Thermodynamic properties of solid phases in the Cu–O–Al2O3 system were measured by means of the EMF method with oxygen concentration galvanic cells based on stabilized zirconia solid electrolytes. The standard Gibbs energies of formation of pure copper oxides and copper aluminates from their component oxides were determined. Copper aluminates were...
Presentation
The manufacturing of modern electrical and electronic equipment (EEE) consumes large amount of scarce valuable metals. The small sized equipment such as smart phones have very high content of these valuable metals. However, their collection rate at End-of-Life (EoL) for recycling is currently very low. To address the prevailing issues related to re...
Presentation
Phase equilibria and thermodynamics in the Ag2SnS3–SnS–Sn2S3–FeS system were investigated using differential thermal analysis, X-ray diffraction, and EMF methods. Determined phase relations were used to express the forming chemical reactions for compounds Ag2FeSn3S8 and Ag2FeSnS4. The forming chemical reactions were performed by applying electroche...
Presentation
Currently, there is an increasing interest to produce energy mainly from renewable sources such as biomass. However, fouling, slagging and corrosion threaten long-term operation availability and costs of biomass power plants. Alkali metal elements in the biomass fuel and the ash fusion behavior are the two major origins contributing to slagging dur...
Chapter
In a race to save the planet of its rapidly depleting natural resources, the use of Secondary Raw Materials (SRMs) as replacements in several processes is currently intensively pursued. In fact, this is currently one of the European Union (EU)’s mandates. Valorization of SRMs is consistent with the circular economy, where resource efficiency is max...
Chapter
Currently, there is an increasing interest to produce energy mainly from renewable sources such as biomass. However, fouling, slagging and corrosion threaten long-term operation availability and costs of biomass power plants. Alkali metal elements in the biomass fuel and the ash fusion behavior are the two major origins contributing to slagging dur...
Chapter
Phase equilibria and thermodynamics in the Ag2SnS3–SnS–Sn2S3–FeS system were investigated using differential thermal analysis, X-ray diffraction, and EMF methods. Determined phase relations were used to express the forming chemical reactions for compounds Ag2FeSn3S8 and Ag2FeSnS4. The forming chemical reactions were performed by applying electroche...
Article
Triangulation of the quaternary Ag–Cd–Sn–S system in the Ag2SnS3–SnS–Sn2S3–CdS part below T = 600 K was performed using X-ray diffraction method. The spatial position of the determined four-phase regions regarding the figurative point of silver was used to write forming chemical reactions. The forming reactions were performed by applying electroche...
Article
Triangulation of the Ag-Hg-Se-I system in the vicinity of quaternary phase Ag4HgSe2I2 was performed by differential thermal analysis, X-ray diffraction and electromotive force (EMF) methods. The spatial position of the phase region Ag4HgSe2I2-Se-HgI2 regarding the figurative point of silver was used to write the chemical reaction of formation of Ag...
Presentation
Full-text available
For WEEE management in an environmentally friendly manner and, simultaneously, to contribute to a circular economy that aims to enhance resource efficiency and security, improvements in the collection of End-of-Life (EoL) EEE and their treatment and recycling are vital. Increased collection rate of EoL EEE requires increased public awareness, while...
Article
In this article, current progress in urban mining related to e-waste recycling is reviewed and associated state-of-the-art recycling technologies are evaluated. As sufficient volume of e-waste is a limiting factor for its recycling economy, the need for the establishment of effective e-waste collection mechanisms, particularly for small sized End-o...
Conference Paper
The roasting of sulfide ores and concentrates is an important process step in the production of metals and chemicals. It involves gas–solid reactions to remove volatile components from the sulfide ores and concentrates. Silver-based sulfosalts are common minerals in precious and base metal sulfide ores. In this work, the sulfosalts in the Ag-(Cu,Bi)...
Article
Oxides and intermetallic phases in the platinum-tellurium-oxygen system have been studied. Thermal stabilities, thermodynamics, and structures of the phases reported in the literature, including the conditions under which PtOx form and decompose, have been compiled and critically evaluated. Heat capacities of the binary phases have been estimated,...
Conference Paper
To reduce the use of fossil fuels and increase self-sufficiency in energy, nowadays, there is an increasing interest to produce energy mainly from renewable resources. Solid biomass is one of the most important renewable energy sources for meeting this target. However, fouling, slagging, and corrosion threaten long-term operation availability and c...
Conference Paper
Full-text available
Currently, increasing demand for valuable metals, complexities of the available raw materials, and earth’s intrinsic limitations pose a challenge to the whole valuable metals production system. The United Nations Environment Program (UNEP) is also calling for an urgent re-think of metals recycling practices as global demand for metals continues to...
Chapter
E-waste management through traditional methods such as disposing in landfills, burning in incinerators or exporting abroad for disposal are no longer options due to the strict environmental regulations. Fortunately, the presence of valuable metals in the e-waste and increasing demand for the metals as well as complexities of the currently available...
Chapter
To reduce the use of fossil fuels and increase self-sufficiency in energy, nowadays, there is an increasing interest to produce heat, power and transportation fuels from renewable resources. Solid biomass is one of the most important renewable energy sources for meeting this target. However, fouling, slagging, and corrosion threaten long-term opera...
Chapter
The sulfosalts Ag0.93Cu1.07S (stromeyerite) and α-AgBiS2 (schapbachite) have been studied under oxidizing conditions at elevated temperatures. The sulfosalts were synthesized from the pure simple sulfides in evacuated quartz ampoules. The synthesized samples were thermally analyzed in the temperature range from 298 to 1173 K by a simultaneous DTA-T...
Book
This collection focuses on energy efficient technologies including innovative ore beneficiation, smelting technologies, recycling and waste heat recovery. The volume also covers various technological aspects of sustainable energy ecosystems, processes that improve energy efficiency, reduce thermal emissions, and reduce carbon dioxide and other gree...