Method for producing silicon for solar cells by metallurgical refining process
US9352970B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 2012 |
| Grant date | May 31, 2016 |
| Priority date | — |
| Expiry date | Jul 6, 2032 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B33/025
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In order to produce metallurgical grade silicon and solar cell grade polysilicon in batches, a method of the present invention comprises: a step of reduction in an arc furnace, consisting of removing C and CO in a silicon reduction atmosphere using silica stone and carbon black by an arc so as to produce metallurgical grade silicon; a step of refining by slag consisting of removing phosphorus (P) and boron (B) by slag; a step of refining by unidirectional solidification consisting of removing metal impurities (Fe, Al, Ti, Mn, etc.) by means of unidirectional solidification; and a step of steam plasma-electromagnetism continuous refining consisting of charging a furnace with the unidirectionally solidified silicon and removing boron (B) by a steam plasma torch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.