Development of a stable process based on the pyrometallurgy-slag preparation-hydrometallurgy process chain for the recovery of Li from Mn-bearing slags (PyroLith) - Sub-project of the BGR working group: Mineral phase and structure analysis of slags containing Li and Mn

Country / Region: Germany

Begin of project: December 1, 2020

End of project: May 31, 2024

Status of project: May 31, 2024

Fig. 1: Color-coded mineral distribution image from the examination of a sample with scanning electron microscope (SEM)-based automated mineralogy (SEM-MLA; measurement mode: GXMAP) Source: BGR

Lithium-ion batteries (LIB) of the NMC type [Li(Ni, Mn, Co)O₂] contain significant quantities of valuable materials such as Al, C, Co, Cu, Fe, Ni, Li and Mn, which can be recycled via suitable processes. In the PyroLith project, a stable process for the recycling of Li and, if applicable, other valuable materials from LIB of the NMC type with affinity to slags, is being developed on the basis of the pyrometallurgy-slag preparation-hydrometallurgy process chain. The focus of the work is directed at an effective recovery of Li in battery-grade quality, even in case of varying input mixtures, and the separation of a residual slag minimized in valuable and environmentally harmful substances, enabling its use as an additive for the construction sector.

To realize the project objectives, it is necessary to carry out work in the fields of thermodynamic modeling, optimized smelting metallurgy, mineral phase and structure analysis, optimized digestion and selective separation, as well as flotation and hydrometallurgy. Decision tools for the selection of an optimized process route will be derived from an overall ecological and economic process evaluation.

In the PyroLith project, the BGR group is in charge for work package 3 "Mineral phase and structure analysis of Li and Mn-bearing slags", which focuses on the chemical and mineralogical characterization of the process samples. Lithium detection is strongly limited when using conventional wavelength- and energy-dispersive X-ray spectroscopic measurement methods. Furthermore, amorphous fractions are only obtained as a sum in quantitative X-ray diffraction analysis. Consequently, the work in the BGR sub-project requires the use of several complementary analytical methods (XRD, SEM-MLA (Fig. 1), EPMA, XRF, ICP-MS, LA-ICP-MS). In addition, the BGR group acts as a collaborating partner in another work package.

Joint project in the competence cluster "Recycling & Green Battery" (greenBatt) financed by the Federal Ministry of Education and Research (BMBF)

Another BGR project in this competence cluster is the Batmix project

Literature:

• Li H., Qiu H., Ranneberg M., Lucas, H., Graupner T., Friedrich, B., Yagmurlu B., Goldmann D., Bremer, J., Fischlschweiger M., 2024, Enhancing Lithium Recycling Efficiency in Pyrometallurgical Processing through Thermodynamic-Based Optimization and Design of Spent Lithium-Ion Battery Slag Compositions. ACS Sustainable Resour. Manage., Published online. https://doi.org/10.1021/acssusresmgt.4c00064
• Li H., Ranneberg M., Fischlschweiger M., 2023, High-temperature phase behavior of Li₂O-MnO with a focus on the liquid-to-solid transition. JOM 75(12), S. 5796-5807. https://doi.org/10.1007/s11837-023-06179-6
• Ranneberg M., Graupner T., 2023, Development of a routine method for the chemical and mineralogical characterization of Li- and Mn-containing slags from the recycling of NMC-type lithium-ion batteries (LIBs), GeoBerlin 2023, DGGV E-Publikation; https://doi.org/10.48380/y338-qw96
• Li H., Qiu H., Ranneberg M., Yagmurlu B., Goldmann D., Graupner T., Fischlschweiger M., 2023, Solidification of lithium and manganese containing slags from lithium-ion batteries - Simulated by coupling CALPHAD with finite element analysis, 50th CALPHAD Conference MIT Boston, Book of Abstracts S. 157
• Li, H., Ranneberg, M., Fischlschweiger, M., 2022, Thermodynamic investigation of the Li2O-MnO system in a certain composition region relevant for slag tailoring in the field of lithium-ion battery (LIB) recycling, GeoMinKöln 2022, p. 228.
• Ranneberg, M, Graupner, T., Goldmann, S., 2022, Chemical and mineralogical characterization of Li- and Mn-bearing slags to increase the recycling efficiency of lithium from lithium-ion-batteries (LIB), GeoMinKöln 2022, p. 322.
• Ranneberg, M., Li, H. Lucas, H., Graupner, T., Fischlschweiger, M., Friedrich, B., Evaluation of Li and Mn influence on Al-Ca-Si-O slag system regarding pyrometallurgical LIB treatment. 8th International Slag Valorisation Symposium, Leuven 2023, 205-209.

Partner:

• Institute of Mineral and Waste Processing, Recycling and Circular Economy Systems (IFAD) TU Clausthal (coordinator)
• Institute of Energy Process Engineering and Fuel Technology (IEVB) TU Clausthal
• Institute for Process Metallurgy and Metal Recycling (IME) RWTH Aachen University
• Institute for Particle Technology (iPAT) TU Braunschweig
• Institute of Machine Tools and Production Technology (IWF) TU Braunschweig
• Federal Institute for Geosciences and Natural Resources (BGR), Hannover

Promotion / document number:

03XP0336C