We have successfully upscaled our fluorine removal step to 100 litres. By adding calcium hydroxide to process water from battery recycling, we precipitated fluorine as CaF₂ and achieved 81% removal after 6 hours at room temperature, followed by efficient filtration.

This purification step is part of our innovative, sustainable lithium recovery process within the EarLi Project (BMWE – „Forschung in der Schwerpunktförderung Batteriezellfertigung“) formed by the coordinator Accurec GmbH and partners IME RWTH Aachen, Öko-Institut e.V. and Evonik Operation GmbH. With the completion of this scale-up experiment, we successfully concluded the project.

The process starts with a continuous, energy-neutral pyrolysis that transforms lithium into a water-soluble form. After mechanical separation, the black mass undergoes selective neutral leaching, where lithium is gently extracted while other metals remain undissolved. The lithium-rich solution is then purified and converted into lithium hydroxide using the novel continuous-flow electrolytic membrane system — all in a single step. Finally, lithium hydroxide monohydrate is precipitated, ready for direct reintegration into new battery precursor production.

This pilot trial not only represents a major success within the project, but also demonstrates our capability to conduct large-scale hydrometallurgical experiments. Our 100-liter leaching reactor enables controlled heating and stirring while continuously monitoring pH and redox potential. Combined with our large filter press, we can efficiently perform leaching and precipitation trials at pilot scale. This setup represents a significant expansion of our existing laboratory-scale and 10-liter experimental capacities.