Silicon Refining
Silicon Recovery from Si-Ca-Al Alloys
Mengyi Zhu, Anne Sofie Arntsen, Jafar Safarian
Abstract
NTNU researchers investigate acid leaching of SisAl-produced silicon alloys, achieving over 99% silicon purity and approximately 82% silicon recovery under laboratory conditions.
Silicon Recovery from Si-Ca-Al Alloys
Silicon refining is a critical stage in developing alternative production routes for high-purity silicon materials.
Researchers at the Norwegian University of Science and Technology (NTNU) investigated the purification of silicon-calcium-aluminum alloys produced through the SisAl aluminothermic reduction process.
Key Research Findings
Laboratory-scale acid leaching of pilot-produced Si-Ca-Al alloy demonstrated:
Silicon purity: Increased from approximately 75% to over 99%.
Calcium removal: 97.5%.
Aluminum removal: 97.1%.
Phosphorus removal: 79.8%.
Silicon recovery: Approximately 82%.
The experiments used hydrochloric acid at 60°C for three hours.
Industrial Significance
The research demonstrates the potential of hydrometallurgical refining to recover silicon from aluminothermically produced alloys.
Further purification and process integration are required to meet photovoltaic and semiconductor-grade specifications.
The results provide valuable evidence for the development of alternative silicon refining technologies.
Original publication: Zhu, M., Arntsen, A. S., & Safarian, J. (2022). Silicon Recovery Via the Acid Leaching of a Si-Ca-Al Alloy Produced by the SisAl Process.
Publication: Proceedings of the Silicon for the Chemical & Solar Industry XVI.
Source: https://doi.org/10.2139/ssrn.4123122
Independent academic research presented by SilexTech for technical reference. Findings are not SilexTech experimental achievements.
