| Title |
Toward sustainability for upcycling SoG-Si scrap by an immersion rotational segregation purification process |
| ID_Doc |
5116 |
| Authors |
Qian, GY; Zhou, L; Lu, JJ; Pang, S; Sun, YW; Pang, JC; Wang, D; Wei, KX; Ma, WH; Wang, Z |
| Title |
Toward sustainability for upcycling SoG-Si scrap by an immersion rotational segregation purification process |
| Year |
2023 |
| Published |
|
| DOI |
10.1016/j.jclepro.2023.137978 |
| Abstract |
Recycling solar grade silicon (SoG-Si) scrap is critical for the sustainability of solar energy and fulfilling to close material loops in circular economics. A major challenge is to control trace impurities efficiently in short time for upgrading scrap to a level of SoG-Si. Here, a new immersion rotational separation purification (IRSP) process is developed to enhance trace impurities removal and the crystal growth from remelted metal by driving the rotating shear flow to improve the efficiency of solute and heat transfer. In a departure from conventional practice that forces extremely low solidification rate limited by the diffusion layer depth at approximately equilibrium solidification interface, here IRSP achieves the deep removal of impurities and the increase of solidification rate by the non-equilibrium rotating solidification interface. In the non-equilibrium solidification process caused by mold rotation, the rotating shear flow not only reduces the diffusion layer depth to improve impurity removal efficiency, but also increases the temperature gradient of the melt at the solidification front that is conducive to the increase of crystal growth rate. The new method is applicable to molten Si and the production of SoG-Si (99.9998%) has been demonstrated, which is able to improve the quality of recycled SoG-Si requiring a low energy input. It is expected that this process helps close high purity Si material loops, reduce resource consumption and the carbon footprint of the photovoltaic industry. |
| Author Keywords |
SoG-Si; Recovery of SoG-Si scrap; Solidification segregation purification; Immersion rotation mold; Separation of trace impurities |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001038148900001 |
| WoS Category |
Green & Sustainable Science & Technology; Engineering, Environmental; Environmental Sciences |
| Research Area |
Science & Technology - Other Topics; Engineering; Environmental Sciences & Ecology |
| PDF |
https://doi.org/10.1016/j.jclepro.2023.137978
|