| Autor: |
Nohira, Toshiyuki, Kani, Naoya, Tsuda, Tetsuya, Hagiwara, Rika |
| Zdroj: |
ECS Transactions; August 2009, Vol. 16 Issue: 49 p239-245, 7p |
| Abstrakt: |
The direct electrolytic reduction of solid SiO2 has been investigated in molten CaCl2 at 1123 K aiming at the production of solar grade Si. The target impurity levels for Si in the present study were calculated from the acceptable impurity levels for SOG-Si and the segregation coefficients for the impurity elements. New types of SiO2 contacting electrodes, in which SiO2 directly contacts with only Si, were devised to reduce metal contaminations in the produced Si. By using the new SiO2 contacting electrodes and a quartz vessel, most of the metal impurities were significantly reduced to be below the target levels. When NH4OH/H2O2/H2O, HCl/H2O2/H2O and HF/H2O2/H2O were used as a cleaning solution, remaining CaCl2 and some metal impurities in the produced Si were removed effectively. A basket type electrode was also tested for the reduction of granular SiO2. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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