The Institute of Applied Physics at TU Bergakademie Freiberg (TU BAF-IAP) drives activities in the field of contactless spectroscopic characterization of various materials for many years. For this purpose, a well-equipped optical lab with excitation wavelengths covering the spectral range from UV to IR and allowing time-resolved (nanosecond time resolution) as well as temperature (15 K … 800 K) and polarisation dependent spatially resolved measurements is available.

The main points of the work lie on the characterization of point defects and the investigation of charge carrier lifetimes in wide-bandgap semiconductor materials. Moreover, the activities cover reliability tests of microelectronic and photovoltaic devices as well as spectroscopic studies on rare-earth element containing compounds.

In the framework of the cluster of competence greenBatt TU BAF-IAP is involved in the project DIGISORT. In order to characterize recycling material streams, alternative optical (e.g. hyperspectral imaging – HIS) and spectroscopic methods (e.g. laser-induced fluorescence – LIF) will be evaluated and applied within this project. As project objective the contact-free measuring technique will be implemented and integrated to the sorting system. This enables an on-line detection of characteristic parameters of the recycling material stream such as size, shape and chemical composition of the particles. Data fusion in real time will lead to a particle discrete information vector as a novel approach in terms of digitalization of the recycling chain. This forms the basis for the application of adaptive process control technologies.

Project participation

DIGISORT

The institute of Mechanical Process Engineering and Mineral Processing of the TU Bergakademie Freiberg is one of the best-known institutions in the field of processing primary and secondary raw materials. Prof. Heinrich Schubert has strongly influenced Freiberg’s competence in mechanical process engineering and processing technology since the 1960s. Furthermore, the work is influenced by the Karlsruhe School of Mechanical Process Engineering of Prof. H. Rumpf and that of Mechanical Solid-Liquid Separation Technology of Prof. W. Stahl. On this basis, research at the institute addresses current scientific issues, especially in the field of solid-liquid separation and processing. In this context, the Institute has established four research groups: surface interactions, solid-liquid separation, computer tomography and processing.

Within the framework of the Green Battery competence cluster, the institute MVT/AT is responsible for the coordination of the sub-projects DigiSort and LOWVOLMON. Within the projects, the institute deals with the characterisation of the particles to be sorted and the effect of changing material properties on the yield and material quality. In addition to the detection of accumulating low-volatile electrolyte components, this also includes the operation of mechanical separation processes on a pilot scale. In addition, the definition of particle- and processing-related reference variables is to contribute to the control of a sorting plant to be commissioned. The particle-discrete information obtained through online measurement is to contribute to increasing the separation accuracy and adapting the sorting process to changing initial parameters.

Project participation

DIGISORT (Lead)

LOWVOLMON (Lead)

The Institute of Chemical Technology (ITC) at TU Bergakademie Freiberg works at the interface between laboratory scale and industrial process engineering. Its work focuses on the areas of raw material chemistry and chemical process development. The aim is to develop and optimise new processes for the sustainable provision of energy and chemical raw materials on the basis of primary and secondary raw materials. Examples are phosphate, lithium, electronic metals (indium, germanium, gallium, rare earths) or methanol. The institute has comprehensive competences in scaling up processes for the extraction of metals from complex polymetallic mixtures as well as the development of ZeroWaste concepts (value-added chemical approach).

Within the competence cluster greenBatt, the ITC is represented in the project EarLiMet. The planned work uses CO2 as a C source in a carbonation process to recover Li2CO3 from residues of Li-ion batteries (black mass). It is a comparatively simple, low-chemical process approach, which makes it possible to process widely diversified input material streams. The complete value chain up to the saleable end product bg-Li2CO3 is used. The process is to be optimised to such an extent that a total Li yield of >95 % is achieved from the black mass used under economic conditions.

Project participation