Antisolvent precipitation to extract the value from end-of-life Nd-Fe-B magnets
| Reference number | |
| Coordinator | Kungliga Tekniska Högskolan - Department of Chemical Engineering |
| Funding from Vinnova | SEK 2 745 000 |
| Project duration | December 2020 - December 2023 |
| Status | Completed |
Important results from the project
The aim of the project has been to develop knowledge around a new process concept for the recycling of magnetic material based on antisolvent crystallization. KTH has developed the crystallization step. Under controlled conditions a product with a purity of 99.3% is obtained with a yield of 88%; this meets the goal of the project (>99% purity). We have also obtained a deeper understanding of the incorporation of impurities in this type of crystals and how iron(II) and iron(III) respectively can affect the crystallization process.
Expected long term effects
The results have been presented at 6 conferences/meetings and will result in 4 publications in journals. Furthermore, the project has been presented at 3 popular science contexts. Increased knowledge about antisolvent crystallization of REE sulphate hydrates and specifically the impact of Fe(II) and Fe(III) respectively on the quality of the crystal product in terms of size, morphology, tendency for agglomeration and purity. Knowledge about impurity incorporation in pure and mixed REE phases respectively. These results are of relevance for process design strategies.
Approach and implementation
Laboratory activities have been conducted by a postdoctoral fellow (Nitin Pawar) who was hired to work in the project. At KTH, regular meetings have been held between Nitin Pawar (postdoctoral fellow), Kerstin Forsberg (project leader and supervisor) and Michael Svärd (project participant). In addition to these meetings, regular project meetings were held online with other partners in the project. The homepage has been important to share and distribute information and results.