Practical trainings, student assistants and theses

In recycling of end-of-life electronic waste (WEEE), copper is recovered as a major metallic component alongside precious metals such as gold, silver, palladium and platinum. Although a significant portion of this waste consists organic materials (polymers) and invaluable inorganic fillers, it remains highly valuable due to presence of these precious and base metals making their recovery very important. During PCB manufacturing, processing, or disposal, dust generated also contain these valuable metals. Such fine dust (20 μm – 315 μm) makes recovery of precious metals challenging. Systematic separation and analysis of these precious metals from PCB dust can offer both economic benefits and reduction in environmental impact. The present thesis focuses on detailed feed characterization of the fine PCB waste fractions. Physicochemical and particle-based methods for metal identification, extraction, and refining will be designed and developed. This approach aims to valorize fine dust classified as hazardous waste through strategies aligned with the principles of the circular economy approach.
In this thesis project, at HIF, HZDR (Department of mineral processing and process metallurgy) we will pursue the innovation along following steps:

1. Pre-processing of PCB dust (comminution, dry/wet sieving and splitting)
2. Pre-characterization in order to know about the size distribution, elemental assay, present phases using (LD, ICP-OES/MS, XRF, SEM)
3. Liquid-liquid particle separation- optimization of the developed process
4. Froth flotation- optimization of the developed process
5. Hydrometallurgical extraction and recovery of Cu and precious metals from concentrated fractions (leaching, solvent extraction, supported liquid membrane)
6. Final characterization of recovered fractions (ICP-MS/OES, TGA, XRF, CHNS, SEM)
7. Conclude with optimizing the economical process for individual metal recovery

• Field of study in process, metallurgy or chemical engineering or similar
• Curious, Interest in experiments, planning and execution
• Basic knowledge about the processes mentioned in the topic
• Good written and oral communication skills in English

• Master thesis
• Start date: by mutual arrangement
• Please upload a short letter of motivation, stating the period of time to start the position, CV, and University certificates

Froth flotation is a widely applied physicochemical process for the enrichment of valuable metals in mineral processing. It operates by exploiting both inherent and induced differences in the surface properties of mineral particles. The efficiency of the process relies on the synergistic use of various reagents, including collectors, frothers, and promoters, which collectively modify surface characteristics and enhance selective separation. Particle size distribution is a critical parameter influencing flotation performance, as it governs the selective recovery of valuables from gangue. Therefore, for the true flotation process, a feed size distribution in the range of 20 μm - 150 μm is generally considered optimal. Which makes recovery for finer (< 20 μm) and coarser size range (> 150 μm) poor due to several reasons. Glass bubbles (GB) are low-density hollow glass spheres which, upon hydrophobization under controlled conditions, act as an ultrafine particle (< 10 μm) collection vesicle enhancing the rate of the recovery process in froth flotation by means of carrier flotation. Recently hydrophobized GB have attracted attention (still only limited studies are available) in flotation due to their low density, structure stability, and tunable surface hydrophobicity, enabling their effective use as carrier particles for improving the particle recovery. This novel concept, carrier flotation exhibits a high potential for application in the flotation of various fine-ultrafine ores.
In this project, at HIF-HZDR (Department of mineral processing) we will pursue the following steps:

1. Characterization of hollow glass bubbles (LD, optical microscopy, SEM)
2. Systematic modification (esterification) and surface characterization (Contact angle measurements and FTIR)
3. Study the effect of HGB in froth flotation (magnetite-quartz-apatite flotation system)
4. Quantitative analysis and characterization of recovered fractions (XRF, ICP-MS/OES, TGA)
5. Optimization and development of a flowsheet for improved recovery and grades.
6. Batch flotation and pilot scale testing

• Field of study in process, mechanical or chemical engineering or similar
• Curious, Interest in experimental investigation,
• Good written and oral communication skills in English

• Master thesis
• Start date: by mutual arrangement
• Please upload a short letter of motivation, stating the period of time to start the position
• Please upload all supporting documents with your CV, and university certificates

The Helmholtz Institute Freiberg for Resource Technology (HIF) pursues the objective of developing innovative technologies for the economy so that mineral and metalliferous raw materials can be made available and used more efficiently and recycled in an environmentally friendly manner. Some work in the Processing Department of the HIF focuses on critical metal recovery from primary raw materials through physical separation—particularly flotation.
Within the new Junior Research Group PURE, we are looking for 2 research assistants who'll be working hands-on in our mineral processing laboratories. You will:

• Assist in laboratory work supporting ongoing doctoral research on metal concentration from mining materials
• Contribute to flotation experiments, sample preparation, and precise data documentation
• Collaborate with an interdisciplinary team; tasks include operating lab equipment, maintaining records, and supporting data analysis
• Hands‑on research experience in a cutting‑edge field essential for the green transition

Initially, we offer a 3‑month contract. Yet there is a perspective for longer‑term involvement—and potentially you could write your thesis at the institute.

• Basic experience in chemical/physical labs
• A structured person, capable of following protocols and documenting their work
• Eagerness to learn and hands‑on mentality
• Digitalization affinity (data handling, basic programming is a plus)
• Role 1: chemistry / process‑engineering background
• Role 2: mechanical‑engineering / electronics background

• Early‑semester graduate students preferred!

• 19h per week
• Starting in November 2026
• Flexible working hours adapted to your study schedule
• The working language is English; German knowledge is beneficial

Nowadays, the processing of secondary resources is becoming more and more important as there is a high demand of critical raw materials. Especially batteries have high amounts of the critical metals Lithium, Cobalt, Manganese and Nickel as oxides used for cathode materials, as well as graphite, which is typically used as anode material. After comminution, these valuable minerals enrich in the fine fraction < 1 mm, which is called black mass. Studies have shown that froth flotation is a suitable technique to separate graphite from the cathode active materials.
In the course of the thesis, the separation of the cathode active materials, i.e. nickel-manganese-cobalt oxides, and the anode material graphite by flotation is investigated, with special focus on the influence of ultrasonication. Flotation tests will be carried out in an Outotec GTK lab cell. The flotation cell is modified in a way that ultrasound (by means of ultrasonication) can be applied during flotation. Therefore, a suitable reagent regime and process parameters for the flotation of black mass have to be established, followed by the development of suitable parameters for ultrasound treatment for this novel cell. Additionally, ultrasound will be tested in a pre-processing step before flotation as an alternative to attritioning by means of intensive shearing. Black mass from real spent lithium-ion batteries that was formerly processed via electrohydraulic fragmentation will be used for the tests. Analysis of the flotation products is done using thermogravimetric analysis and elemental analysis.

• Field of study in process, mechanical or chemical engineering or similar
• Interest in experimental investigation
• Good written and oral communication skills in English
• Please upload a short letter of motivation stating the period of time and your current grade overview to the applicant portal

• Student thesis
• Start date: by arrangement
• We offer an innovative multidisciplinary international research environment with relevance to key issues in resource technology

Cobalt (Co) and Molybdenum (Mo) are critical raw materials widely used across industry and predominantly obtained from primary ores. However, the depletion of high-grade mineral ores and limited extraction efficiency of lower-grade ores have created concerns about the long-term sustainable supply of these metals. As a result, the focus has shifted to recovering valuable metals from secondary resources such as end-of-life products, industrial waste, and manufacturing by-products. Among these secondary sources, Co-based catalytic waste has drawn attention, which can be an important secondary resource for Co, Mo, and Bi. In this study, an industrial catalytic waste rich in cobalt and bismuth is proposed for investigation as a potential secondary resource for the recovery of valuable metals, particularly cobalt and molybdenum.
The goal of the proposed master thesis is to develop a hydrometallurgical process for the recovery of valuable metals, especially Co and Mo from the Co-Bi-rich catalytic waste. Innovative hydrometallurgical approaches will be investigated for the selective recovery of cobalt and molybdenum, comprising leaching, selective precipitation, and solvent extraction. The operating parameters of each stage will be optimized to achieve higher metal recovery. In addition, the solvent extraction stage will be further enhanced through the development of a selective supported liquid membrane (SLM) system. The performance of solvent extraction and SLM-based separation will be systematically compared in terms of selectivity, extraction efficiency, and overall metal recovery to identify the most effective process for cobalt and molybdenum recovery.

• Bachelor's degree in Chemistry, Chemical Engineering, Environmental Engineering, or related field
• Knowledge of hydrometallurgical methods such as Leaching, precipitation, solvent extraction, crystallization, and membrane technologies
• Knowledge of analytical techniques such as ICP-OES, AAS, MS or similar for metal concentration analysis
• Good oral and written communication skills in English
• Ability to work independently and systematically

• Conduct literature research on the recovery of cobalt, molybdenum, and other metals through Hydro metallurgic process and membrane technologies
• Characterization and understanding of the feed materials using various techniques, XRD, FTIR, ICPOES, XRF, etc before and after the experimental process
• Optimize experimental conditions for high recovery efficiencies for cobalt and other valuable metals
• Prepare a comprehensive thesis report and, if possible, present findings at relevant conferences or workshops.

• Duration: 6 months
• Start Date: Start in October 2026 is possible
• Funding: Remuneration according to HZDR internal regulations

• Work inside an existing project for investigating and simulating strongly correlated quantum systems.
• Extend an already established method based on tensor networks to other fermonic and spin systems.
• Perform your own numerical calculations and evaluate the resulting data.
• Summarize the results and publish them in a paper and/or present them at a conference.

• Enrolment in physics, chemistry, computer science or a related field
• Interest, enthusiasm and ability to work independently and systematically
• Basic programming skills in Python and first experiences in HPC computing
• Knowledge of the basics of quantum physics and numerical methods
• First experiences in quantum many-body physics and numerical methods for quantum many-body physics desirable

• Working in an international team
• Compensation as a student research assistant (working hours to be agreed)
• Remote work possible; occasional on-site work would be beneficial
• Supervision within an interdisciplinary early-career research group
• Flexible starting date by agreement

Social Impact describes the influence that research, projects, or organizations have on society. It is therefore important to science because it shows that scientific findings are not only significant within the scientific community but also benefit people, the environment, the economy, and politics. Social Impact gains importance to justify research and other public project spending in times of tight public budgets, science skepticism and governmental mistrust. Showing the impact of one’s project can make or break a funding application.
There is a very diverse selection of methods to analyze the social impact of research and projects. Each of those methods has prerequisites that need to be taken into account for optimum usage. The goal of this master thesis is to generate an overview of available methods of social impact assessment (based on current literature) and develop an AI-aided application for selection the most useful and practical model of social impact assessment.

Proposed research question: Which prerequisites influence the choice of a social impact assessment method and how can the most suitable method be chosen?

• Enrolled in Master Program in Business Administration, Economics, Social Sciences or related field at a German university
• Co-supervising professor from Home University needed

• Close work with the team from the department “Human & Technology” @HZDR, research site in Leipzig
• Remote work possible, some in person work beneficial
• Start in November /December 2026, projected time for completion of thesis 6 months
• This thesis is not paid!

There is also the possibility to support through a paid student assistant position in addition to writing your thesis with us.

Transparent conductive oxides (TCOs) are essential components for many everyday applications and devices, such as displays, smart windows, area lighting, flexible electronics, and solar modules. The most commonly used TCO is tin-doped indium oxide (ITO). In order to reduce the demand for the critical raw material indium, zinc oxide-based TCOs often represent a good alternative. However, ZnO is not suitable for applications involving high temperatures or aggressive environments. Tin oxide, SnO2, which exhibits the best thermal and chemical stability among known TCOs, offers a better alternative for applications in concentrated solar power, perovskite solar cells, and as electrodes in high-power electronics.
The most important functional properties of TCOs are high transparency in the visible wavelength range and high electrical conductivity. Both are strongly dependent on point and structural defects in the materials. Interestingly, these defects in SnO₂ are still not sufficiently characterized and understood, and are therefore the subject of ongoing scientific research. To improve the knowledge base of tin oxide-based TCOs, Bachelor's, Master's, or Diploma thesis topics are - among others - offered on the following sub-aspects:
1.) Identification of point defects of undoped Sn oxide thin films and correlation with the electrical properties
2.) Optimization of the electrical and optical properties of doped Sn oxide thin films
3.) Correlation of growth conditions and structural properties of tin oxide thin films
State-of-the-art in-situ and ex-situ methods such as magnetron sputtering, ellipsometry, UV-vis-NIR-FTIR and Raman spectroscopy, and X-ray diffraction will be employed.

• University enrollment in physics, chemistry, or materials science and good grades or better
• Interest, enthusiasm and ability for scientific work
• Basic programming skills and proficiency in using office and scientific software
• Fluent English language skills

• Payment includes the standard expense allowance

1D- und 2D-Ramanspektroskopische Meßreihen oder auch Maps liefern detaillierte ortsaufgelöste chemische Informationen über die untersuchten Proben. Damit kann z. B. die Komponentenverteilung in Stoffgemischen quantitativ bestimmt oder die Homogenität einphasiger Proben gezeigt werden. Andererseits lassen sich lokale Strukturveränderungen, Spannungszustände, Stapelfolgenänderungen in 2D-Materialien und Punktdefekte charakterisieren. Voraussetzung dabei ist eine möglichst engmaschige Datenerfassung bis hin zur Auflösungsgrenze der verwendeten Laserstrahlung sowie eine große Anzahl an Messpunkten. Mit modernen Spektrometern sind Messzeiten im Sekundenbereich gut realisierbar. Die Umsetzung der spektroskopischen in eine chemische Information erfordert dann die Extraktion von Parametern wie Schwingungsfrequenz, Intensität und Linienbreite durch Spektrenanpassung. Die Gerätesoftware bietet dafür nur eingeschränkte Möglichkeiten.
Im Rahmen einer Graduierungsarbeit soll in Zusammenarbeit mit dem HZDR-Rechenzentrum ein Auswertealgorithmus für die automatisierte Auswertung von 1D- und 2D-Ramanspektroskopischen Meßreihen entwickelt, an Beispielen getestet und dokumentiert werden.

1. Studium der Werkstoffwissenschaften, Physik oder Chemie
2. Interesse, Freude und Befähigung für wissenschaftliche Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Sehr gute Englisch-Kenntnisse

Die Arbeit ist in die umfangreichen Aktivitäten der Abteilung Nanoelektronik (FWIO) zu 2D-Werkstoffen eingebettet. Sie kann jederzeit aufgenommen werden.

Wir beschäftigen uns mit der Entwicklung von PET-Radiotracern, die Rezeptoren im Tumormikromilieu (TME = tumor microenvironment) für die Diagnostik und Therapie von Krebs sichtbar machen. Dazu werden geeignete tumoraffine Leitstrukturen identifiziert (niedermolekulare organische Moleküle, Peptide und Peptidomimetika), synthetisiert und mit einem geeigneten Radionuklid kovalent (z. B. Fluor-18, Iod-123) oder über einen Chelator (z. B. Gallium-68, Lutetium-177) markiert. Diese Radioliganden werden in vitro an Tumorzelllinien und in vivo im Tiermodell hinsichtlich einer Anwendung in der Nuklearmedizin getestet. Langfristiges Ziel ist die Translation der entwickelten Radiotracer in die Klinik als Diagnosewerkzeug (PET/CT) oder nach Markierung mit einem Beta- oder Alphastrahler für die Endoradiotherapie von Tumorerkrankungen.
Im Rahmen eines Studentenpraktikums oder einer Bachelor- oder Masterarbeit sollen organische Wirkstoffmoleküle synthetisiert und für eine anschließende radiochemische Markierung modifiziert werden. Die neuen Radioliganden werden dann biologisch in vitro und in vivo untersucht.

• Studium der Chemie
• Gute Noten in organischer Synthesechemie
• Fähigkeit sich in ein interdisziplinäres Wissenschaftler-Team einzugliedern
• Bereitschaft zum Umgang mit Radioaktivität
• Gute Kenntnisse der deutschen und englischen Sprache

• Beginn nach Absprache jederzeit möglich
• Praktikumsdauer mind. 4 Wochen, mit möglichst täglicher Anwesenheit

Tower power plants represent the latest generation of solar thermal power generation systems (see figure). Large-area mirror arrays concentrate sunlight onto a central absorber, where it is converted into thermal energy, which is then transferred to a heat transfer medium. Compared to photovoltaics, solar thermal energy has the inherent advantage of energy storage capacity and availability on demand. The challenge for further increasing the efficiency of solar power plants lies in developing materials with temperature stability up to 800 °C in air. Within the framework of graduate theses and research projects, thermally stable coatings for the core components of solar tower power plants will be developed and tested. State-of-the-art in-situ and ex-situ methods such as magnetron sputtering, ellipsometry, UV-vis-NIR-FTIR retroreflector, and Raman spectroscopy will be employed.
The following tasks are offered in this area:
i) Design and optical simulation of solar-selective coating stacks for solar power plants
ii) Deposition, optimization, and characterization of the structural, optical and electrical properties of individual components and whole coating stacks for solar power plants
iii) Ex situ and in situ investigations of the thermal stability of individual components and entire coating stacks for solar power plants
Other topics can be discussed individually.

1. University program in physics, chemistry, or materials science with good grades or better
2. Interest, enthusiasm, and ability for scientific work
3. Basic programming skills and proficiency in using office and scientific software
4. Fluent English language skills

This work is carried out in collaboration with national and international partners, payment includes the standard expense allowance