Browsing by Author "Klemettinen, Anna"

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Circular And Sustainable : Evaluating Lithium-Ion Battery Recycling using a Combined Statistical Entropy and Life Cycle Assessment Methodology
(2024-09-23) Tas, Gulsah; Klemettinen, Anna; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
While there has been a growing interest on the concept of Circular Economy (CE), its correlation with sustainability remains controversial. In this work, the combination of Statistical Entropy Analysis (SEA) and Life Cycle Assessment (LCA) is proposed as a new methodology to evaluate recycling processes from the perspective of materials circularity and environmental impacts using a Li-ion battery recycling process as a case study. This work addresses the need of quantitative circularity indicators, as SEA evaluates the concentration of materials at a systems level, while LCA measures the environmental impact of recycling processes in comparison with virgin raw materials production. It was found that process optimization points can be found by simultaneously accounting for materials recovery and the LCA categories of global warming potential, ozone depletion and mineral resource scarcity. Furthermore, a strong correlation was found for the first time between the recovery of critical elements and the environmental impact of raw materials production. The proposed methodology thus offers a robust analysis of a product lifecycle that aids in its design and optimization from the CE perspective.
A grave-to-cradle analysis of lithium-ion battery cathode materials using material and energy circularity indicators
(2024-09-15) Vierunketo, Minerva; Klemettinen, Anna; Reuter, Markus A.; Santasalo-Aarnio, Annukka; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
The future demands for lithium-ion batteries required for powering the electrification transition in transportation and energy storage will lead to vast amounts of waste, demanding proper end-of-life strategies. As various recycling routes are continuously developed to address this issue, a significant challenge is the fair comparison of processes entailing different unit operations and transformation stages. Indeed, the choice of metallurgical or direct recycling routes results in diverse materials flows and energy demands. To allow a suitable comparison between technologies, this work presents a grave-to-cradle analysis of cathode materials (i.e., lithium cobalt oxide) considering three recycling processes representative of the most popular routes (i.e., pyrometallurgical, hydrometallurgical, and direct recycling). Unlike previously published works, a system-level analysis of both material recovery and energy preservation was carried out using statistical entropy and exergy analysis, respectively. Furthermore, comparison of processes using exentropy, a recently proposed circularity parameter combining both material recovery and energy preservation, was performed for the first time. The results highlight the need of a robust multidimensional analysis of processes to properly determine their suitability according to the needs of the circular economy. When materials and energy preservation were analyzed independently, two different routes were identified as optimal. The need of a robust multidimensional analysis of processes to properly account for the goals of the circular economy is thus highlighted. Exentropy analysis suggested that direct recycling provides the optimum alternative in terms of energy utilization for the recovery of materials.
Hydrogen as the reducing agent in non-ferrous metals production, a literature review
(2022-04-19) Engblom, Sonja
Kemiantekniikan korkeakoulu | Bachelor's thesis
Improving the flotation recovery of Cu from flash smelting slags by utilizing cellulose-based frother formulationss
(2022-05-15) Nuorivaara, Ted; Klemettinen, Anna; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Froth flotation is an operation currently used for the recovery of Cu from pyrometallurgical smelting slags due its simple operation and relatively low operational costs. While it has been utilized for many decades, it may be necessary to develop strategies that improve Cu recovery from slags, as the unprecedented increase in Cu demand has made industrial waste and side streams economically relevant sources of metals. This study presents a novel chemistry-based approach for the flotation of Cu from smelting slags by utilizing an amphiphilic cellulose-surfactant mixture as a flotation frother, hereby referred to as CellFroth. The present work pursues two main objectives: i) to improve the performance of flotation for the treatment of smelting slags and ii) to accomplish a first proof of concept for frothers produced from renewable sources in the context of industrial waste treatment. The flotation performance of CellFroth was compared with a commercially available additive (i.e., DowFroth250) and hydroxypropyl methyl cellulose (HPMC). The results showed significant advantages in performance for CellFroth. At the highest collector concentration, Cu recovery was higher with CellFroth compared to DowFroth 250 and pure HPMC (73%; 62% and 65% respectively). A 75% reduction in xanthate concentrations had negligible effects on Cu recovery for CellFroth (70%), while recoveries decreased drastically with DowFroth250 (47%) and pure HPMC (50 %). Finally, CellFroth consistently reached comparable concentrate productivity (grade and recovery) as DF250 within significantly shorter flotation times. The use of CellFroth thus offers the possibility of increasing the Cu recovery from flash smelting slags, while reducing the environmental impact of the process by using a frother produced from sustainable sources and simultaneously reducing xanthate consumption.
Leaching of rare earth elements from NdFeB magnets without mechanical pretreatment by sulfuric (H2SO4) and hydrochloric (HCl) acids
(2021-12) Klemettinen, Anna; Żak, Andrzej; Chojnacka, Ida; Matuska, Sabina; Leśniewicz, Anna; Wełna, Maja; Adamski, Zbigniew; Klemettinen, Lassi; Rycerz, Leszek
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
A simplified approach for rare earth elements leaching from NdFeB (neodymium-iron-boron) magnets was investigated. The possibility of simplifying the magnet recycling process by excluding grinding, milling and oxidative roasting unit operations was studied. Attempts to skip the demagnetization step were also conducted by using whole, non-demagnetized magnets in the leaching process. The presented experiments were conducted to optimize the operating conditions with respect to the leaching agent and its concentration, leaching time, leaching temperature and the form of the feed material. The use of hydrochloric and sulfuric acids as the leaching agents allowed selective leaching of NdFeB magnets to be achieved while leaving nickel, which is covering the magnets, in a solid state. The application of higher leaching temperatures (40 and 60◦ C for sulfuric acid and 40◦ C for hydrochloric acid) allowed us to shorten the leaching times. When using broken demagnetized magnets as the feed material, the resulting rare earth ion concentrations in the obtained solutions were significantly higher compared to using whole, non-demagnetized magnets.
A multi-dimensional indicator for material and energy circularity: proof-of-concept of exentropy in Li-ion battery recycling
(2023-11-17) Vierunketo, Minerva; Klemettinen, Anna; Reuter, Markus; Santasalo-Aarnio, Annukka; Serna Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Recycling processes are an important stage in the raw material life cycle, as it enables the transition from a linear economy into a circular one. However, the currently available indicators of productivity in recycling technologies respond to the needs of a linear economy. In this work, a parameter called “exentropy” is proposed, offering the possibility to simultaneously account for mass preservation and the energy efficiency of transformative stages. As a proof-of-concept of this indicator, the analysis of a lithium-ion battery recycling process under various concentrations of a leaching reagent (i.e., 0.1M, 1M, and 2M) is presented. It is shown that, when the energy or mass dimensions are considered independently, the processes considered optimal may have conflicting characteristics. In contrast, the multi-dimensional analysis identified the process option offering the best compromise for both material and energy preservation, an aspect closer to the goals of the circular economy.
Pyrolysis as one of the steps in recycling of lithium-ion batteries
(2022-05-11) Terho, Tara
Kemiantekniikan korkeakoulu | Bachelor's thesis
Pyrometallurgical options for recycling of waste lithium-ion batteries - circular economy approach
(2023-05-20) Halonen, Juho
Kemiantekniikan korkeakoulu | Bachelor's thesis
Recovering value from end-of-life batteries by integrating froth flotation and pyrometallurgical copper-slag cleaning
(2022-01) Rinne, Tommi; Klemettinen, Anna; Klemettinen, Lassi; Ruismäki, Ronja; O’Brien, Hugh; Jokilaakso, Ari; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
In this study, industrial lithium-ion battery (LIB) waste was treated by a froth flotation process, which allowed selective separation of electrode particles from metallic-rich fractions containing Cu and Al. In the flotation experiments, recovery rates of ~80 and 98.8% for the cathode active elements (Co, Ni, Mn) and graphite were achieved, respectively. The recovered metals from the flotation fraction were subsequently used in high-temperature Cu-slag reduction. In this manner, the possibility of using metallothermic reduction for Cu-slag reduction using Al-wires from LIB waste as the main reductant was studied. The behavior of valuable (Cu, Ni, Co, Li) and hazardous metals (Zn, As, Sb, Pb), as a function of time as well as the influence of Cu-slag-to-spent battery (SB) ratio, were investigated. The results showcase a suitable process to recover copper from spent batteries and industrial Cu-slag. Cu-concentration decreased to approximately 0.3 wt.% after 60 min reduction time in all samples where Cu/Al-rich LIB waste fraction was added. It was also showed that aluminothermic reduction is effective for removing hazardous metals from the slag. The proposed process is also capable of recovering Cu, Co, and Ni from both Cu-slag and LIB waste, resulting in a secondary Cu slag that can be used in various applications.
Recovery of Rare Earth Elements from the Leaching Solutions of Spent NdFeB Permanent Magnets by Selective Precipitation of Rare Earth Oxalates
(2023-07) Klemettinen, Anna; Adamski, Zbigniew; Chojnacka, Ida; Leśniewicz, Anna; Rycerz, Leszek
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
After mechanical pre-treatment, the typical hydrometallurgical route of NdFeB magnet recycling starts with leaching in acidic solutions. However, due to the high concentration of iron ions in the leaching solution, the selective recovery of rare earths from the solution is challenging. In our work, the selective precipitation of rare earth oxalates as a potential separation method was proposed. The precipitation of neodymium oxalate was first tested on model solutions, which was then followed by experimental tests carried out on real solutions after the leaching of NdFeB magnets. The recovery of rare earths in the form of oxalates was investigated with the use of different amounts of oxalic acid in relation to its stoichiometric amount. The most efficient separation of rare earths was observed in the case where sulfuric acid was used for leaching. The use of oxalic acid in stoichiometric amounts resulted in the precipitation of about 93% of all rare earths present in the solution, whereas the concentration of Fe and other elements (Ni, Co, and B) practically did not change. An increase in oxalic acid of 20% and 40% more than the stoichiometric amount (100%) led to the increase in the precipitation efficiency of rare earths to 96.7% and 98.1%, respectively. However, the use of oxalic acid in a 1.4 ratio caused a 7% decrease in Fe concentration, which suggests Fe co-precipitation. In order to investigate a possibility of further increasing the separation of rare earths from iron, an additional method was tested, in which iron was first oxidized from Fe2+ to Fe3+ before the precipitation of rare earth oxalates.
Review of existing state-of-the-art copper recovery methods from waste lithium-ion-batteries
(2021-12-17) Chukhray, Dmitriy
Kemiantekniikan korkeakoulu | Bachelor's thesis
Semicontinuous Process of Rare Earths Recovery from End-of-Life NdFeB Magnets on a Large Laboratory Scale
(2023-07) Klemettinen, Anna; Adamski, Zbigniew; Leśniewicz, Anna; Rycerz, Leszek
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Hydrometallurgical methods for NdFeB recycling typically consist of several unit operations and require the extensive use of energy, water and chemicals which may negatively affect the applicability of these methods on an industrial scale. Based on the data from our previous studies, a simplified process of rare earth elements (REE) recovery from spent NdFeB magnets was developed further. The possibility of regenerating the leaching agent, as well as water recovery, in the process was investigated. This study also investigates a possibility of scaling up the recycling process developed on a laboratory scale. The leaching and precipitation stages were tested on a larger scale, where about 1 kg of end-of-life magnets was used as feed to the leaching step. In this study, end-of-life magnets were obtained from the manual disassembly of computer hard disc drives. After disassembly, the magnets were demagnetized, broken into pieces and fed to the leaching process. In the following step, rare earths were precipitated in the form of oxalates. The rare earths’ precipitation efficiency reached a maximum of 95.6%. The results showed that the co-precipitation of Fe highly depends on the amount of oxalic acid used as the precipitant. Smaller losses of Fe were achieved while using a stoichiometric amount of oxalic acid in relation to the REE present in the solution. At the end of the investigated process, rare earth oxalates were calcinated to oxides and their purity was investigated. The recirculation of a solution after oxalate precipitation and acid regeneration was tested with hydrochloric and sulfuric acids used as leaching agents. Solution recirculation was found to be possible only in the case of hydrochloric acid.
A simple methodology for the quantification of graphite in end-of-life lithium-ion batteries using thermogravimetric analysis
(2023-10-20) Gomez-Moreno, Luis Arturo; Klemettinen, Anna; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
A new method based on thermogravimetric analysis was developed to measure the graphite content in battery material mixture. This approach exploits the thermochemical reduction of cathodic Li-transition metal oxides with anodic graphite at elevated temperatures under an inert atmosphere. Using known composition artificial mixtures, a linear correlation between cathode mass loss and sample graphite content was observed. The method was validated using industrial black mass samples and characterized traditionally to estimate and rationalize potential error sources. Thermal degradation profiles of industrial battery waste reflected those in the artificial system, demonstrating its applicability. This work also demonstrates that thermogravimetric degradation profiles can distinguish between a cathode consisting of single or multiple Li-metal oxides. Although accuracy depends on active component mixture content and impurities, it is demonstrated that the method is useful for a fast graphite content estimation. Unlike other graphite characterization techniques, the method proposed is simple and inexpensive.
Sulfation roasting - Applicability for battery scrap recycling, a literature review
(2022-05-19) Kumlin, Mikaela
Kemiantekniikan korkeakoulu | Bachelor's thesis
Time-Dependent Behavior of Waste Lithium-Ion Batteries in Secondary Copper Smelting
(2022-10) Klemettinen, Anna; Klemettinen, Lassi; Michallik, Radosław; O'Brien, Hugh; Jokilaakso, Ari
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
As the electrification sector expands rapidly, the demand for metals used in batteries is increasing significantly. New approaches for lithium-ion battery (LIB) recycling have to be investigated and new technologies developed in order to secure the future supply of battery metals (i.e., lithium, cobalt, nickel). In this work, the possibility of integrating LIB recycling with secondary copper smelting was further investigated. The time-dependent behavior of battery metals (Li, Co, Ni, Mn) in simulated secondary copper smelting conditions was investigated for the first time. In the study, copper alloy was used as a medium for collecting valuable metals and the distribution coefficients of these metals between copper alloy and slag were used for evaluating the recycling efficiencies. The determined distribution coefficients follow the order Ni >> Co >> Mn > Li throughout the time range investigated. In our study, the evolution of phases and their chemical composition were investigated in laboratory-scale experiments under reducing conditions of oxygen partial pressure p(O2) = 10−10 atm, at 1300 °C. The results showed that already after 1 h holding time, the major elements were in equilibrium. However, based on the microstructural observations and trace elements distributions, the required full equilibration time for the system was determined to be 16 h.
Towards Integration of Ni-Slag Cleaning Process and Lithium-Ion Battery Recycling for an Efficient Recovery of Valuable Metals
(2024-10) Klemettinen, Anna; Klemettinen, Lassi; Rinne, Tommi; O'Brien, Hugh; Jokilaakso, Ari; Serna-Guerrero, Rodrigo
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Spent lithium-ion batteries (SBs) are important sources of valuable and critical raw materials. An integration of battery recycling with well-established primary processes for metals production has many advantages. In this work, the recycling of two battery scrap fractions obtained from mechanical pretreatment was integrated with a Ni-slag cleaning process at laboratory scale. Graphite from SBs acted as the main reductant, and the reduction behavior of major and trace elements was investigated as a function of time at 1350 °C. Major CO and CO2 concentrations, as well as minor amounts of SO2, NO2, CH4, and C2H4, were detected in the off-gas line. The evolution of gases took place within the first minutes of the experiments, which indicated that metal oxide reduction reactions as well as decomposition of the organic binders both happened very rapidly. This result is in line with the analytical results obtained for the slag phase, where the most significant metal oxide reduction was observed to take place within the first 5 to 10 minutes of the experiments. The distribution coefficient values for Co and Ni between metal alloy and slag as well as between matte and slag showed no significant differences when battery scrap fractions with different compositions were used. The addition of Ni-concentrate in the starting mixture resulted in increasing recoveries of Ni and Co, as well as improved settling of the matte phase.