Practical trainings, student assistants and theses

Platinum group metals (PGMs), particularly rhodium (Rh), palladium (Pd), and platinum (Pt), are regarded as the "vitamins" used in the modern industry. PGMs are crucial components of fuel cells, jewelry, computers, cell phones, automobile catalysts, etc. Their distinct physical and chemical characteristics, such as their corrosion resistance, chemical inertia, and catalytic activity, account for their extensive application and create alloys to enhance the characteristics of other transition metals. Because of their unique properties, PGMs are seldom replaced with other elements or compounds in applications. However, PGM deposits in the earth's crust are limited. The utilization of secondary resources, such as recycling waste materials, could mitigate the issue of PGM scarcity. Several conventional methods have been used for recovering PGM from secondary sources. Among the separation technologies, membrane separation offers the continuous and selective recovery of individual PGMs with no adverse environmental effects.
Supported liquid membranes (SLM) are a chemically driven membrane method in which a solvent phase contains an organic ligand that preferentially binds to a metal in the feed solution. The metal-ligand combination is subsequently diffusively carried across the membrane support and discharged into the receiving phase. This approach is particularly useful for metal ion separation because the organic carrier generates lipophilic metal-organic ligand complexes. This continuous permeation technique combines extraction and stripping procedures with less chemical reagents. The objective of the thesis work deals with the employment of task-specific organic ligands as carriers in the supported liquid membrane system for the selective recovery of platinum group metals from secondary source leachates and understanding the transport mechanism using different mathematical modeling approaches.

• Conduct literature research on supported liquid membranes using various organic carriers and their applications in metal recovery
• Design and conduct laboratory experiments using supported liquid membrane studies using task-specific organic carriers with several parameters such as pH, concentration, the thickness of membrane, feed solutions, etc.
• Analyse and interpret data on membrane selectivity, flux rates, fouling resistance, and metal recovery efficiency
• Optimize experimental conditions targeting high recovery rates for Platinum, Palladium, and Rhodium
• Prepare a thesis report and present findings at conferences or workshops

• Bachelor's degree in Chemistry, Chemical Engineering, Environmental Engineering or related field
• Knowledge of hydrometallurgical processes and membrane separation technologies
• Knowledge of analytical techniques such as ICP-OES, AAS, or similar for metal concentration analysis
• Duration: 6 months
• Start Date: Start in 2025 is possible
• Funding: Remuneration according to HZDR internal regulations

Vanadium and manganese are essential in high-strength steel alloys, battery technologies (notably vanadium redox flow batteries), and various chemical processes. Due to their industrial significance, recovering these metals from residual wash water along with leaching acids promotes environmental and economic sustainability. This study aims to Investigate and optimize a membrane filtration (nanofiltration) process for the selective recovery of vanadium and manganese, along with acid reclamation, from both acid raffinate and residue wash water solutions. The research evaluates the performance of various membranes focusing on their efficiency in concentrating vanadium and manganese while minimizing the co-permeation of iron, calcium, and other minor elements.
The objective of the work is to develop a process yielding a concentrated solution rich in vanadium and manganese for further precipitation, solid-liquid separation and hydrometallurgical steps, ultimately facilitating the recovery of vanadium as vanadium pentoxide (V₂O₅). The outcomes will offer valuable insights into the design and operation of membrane filtration systems for recovering critical metals and leaching agents from industrial effluents, supporting sustainable resource management practices in the metallurgical industry.
In addition to metal recovery, this research addresses acid reclamation following solvent extraction (SX) and supported liquid membrane process, with the goal of reducing chemical consumption. Acid recovery from the raffinate will be also explored, with organic contaminants removed via sorbents, such as activated charcoal. The reclaimed acid can then be recycled back into the leaching circuit, establishing a more sustainable process loop.

• Educational Background: Bachelor's / Master’s degree in Metallurgical Engineering, Chemical Engineering, Environmental Engineering or related field

• Knowledge of hydrometallurgical processes and membrane separation technologies
• Basic laboratory skills and familiarity with equipment for Nano filtration, filtration testing, and solution analysis
• Knowledge of analytical techniques such as ICP-MS, AAS, or similar for metal concentration analysis

• Conduct a literature review on nanofiltration technology and its application in metal and acid recovery
• Design and carry out laboratory experiments with selected nanofiltration membranes, focusing on variables like pressure, pH, and concentration
• Analyze and interpret data on membrane selectivity, flux rates, fouling resistance, and metal-acid recovery efficiency
• Optimize filtration conditions through experimentation, targeting high recovery rates for vanadium and manganese
• Prepare a comprehensive thesis report and, if possible, present findings at relevant conferences or workshops

• Duration: 6 months
• Start Date: Start in 2025 is possible
• Funding: Remuneration according to HZDR internal regulations
• Supervision and Support: The candidate (f/m/d) will be supervised with regular guidance, training on laboratory protocols, and support in analytical techniques

Rare earth elements (REEs) are vital for several applications in various industrial sectors. Studies on REEs recovery from various secondary resources revealed that spent permanent magnets contain a significant amount (approximately 31-32 wt%) of rare earth metals. However, the presence of Fe poses a challenge for recovering REE from the leachate solution. It was observed that the REE will also co-precipitate with Fe upon precipitation, resulting in the loss of resources. To address this, an ion exchange method has been proposed for selective recovery of REE from leachate solutions. Our latest research reveals that selective ligands based on different media can recover REE from aqueous solutions even in the presence of other metals. The current study intends to develop task-specific resins based on selective ligands for effective REE recovery from spent NdFeB magnet leachate solutions as well as to investigate the efficiency of these resins for upscaling technology.

• Knowledge of hydrometallurgy and organic synthesis
• Experience in coordination chemistry, and technical chemistry is advantageous
• Good oral and written communication skills in English or German
• Ability to work independently and systematically

• Synthesis and purification of novel task-specific organic ligands
• Impregnation studies with various ion exchange resins
• Application of resins on recovery of rare earth metal ions from various spent magnet leachates and other sources
• Start date: Either an immediate start or a start in 2025 is possible
• Duration: 6 months
• Remuneration according to HZDR internal regulations