| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
REWAS 2025: Sustainable Practices in Strategic and Critical Raw Materials: Exploring Supply Chain Resilience and Recycling Innovations
|
| Presentation Title |
From Waste to High-Purity Silicon: Refining of Silicon by Directional Solidification and Crystal Pulling Method |
| Author(s) |
Katarina Jakovljevic, Eivind Johannes Øvrelid, Nagarajan Somi Ganesan, Pål Tetlie, Casper Van der Eijk, Maria Wallin, Gabriella Tranell |
| On-Site Speaker (Planned) |
Katarina Jakovljevic |
| Abstract Scope |
Since 2014, silicon (Si) has been classified as a critical raw material by the European Union due to its high risk of supply disruption and significant economic importance. The SisAl process for Si production reduces direct CO2 emissions and also promotes the utilisation of secondary raw materials such as quartz fines, aluminium dross and scrap, enabling a shift from today's carbothermic reduction process to a process in line with circular economy goals. The present study focuses on the purification of a Si alloy acquired from slag-refined mixture of SisAl metal and kerf. 99.9% pure silicon was successfully obtained by utilising the directional solidification method, which relies on the different distribution of impurities during metal solidification. As an alternative, the Si alloy was also blended with high-purity Si and subjected to refinement by crystal pulling to assess its suitability for applications demanding very high Si purity. In this process, an ingot with 5N purity was obtained. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Other, Other, Other |