Silicon refining process
US5820842A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1996 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Sep 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B13/028
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The process calculates the amount of silica and oxidizing agent to use in a refining process for metallurgical-grade silicon. The calculation for silica takes into account (1) the aluminum content of the previous batch of refined silicon; (2) the calcium content of the previous batch of refined silicon; (3) the trend in the aluminum content of the unrefined silicon; and (4) the age of the ladle used for refining. The process then calculates the amount of silica based on a predetermined minimum amount of silica to add, a predetermined maximum amount of silica to add and the amount of silica added to the previous batch of refined silicon. The calculation for oxidizing agent is based on (1) the aluminum content of the previous batch of refilled silicon; (2) the calcium content of the previous batch of refined silicon; and (3) the age of the ladle. The process then calculates the amount of oxidizing agent to add based on a maximum amount of oxidizing agent to add and the amount of oxiziding agent added to the the previous batch of refined silicon. By following this process, an increase in the amount of chemical-grade silicon is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.