Silicon refinery
US4213937A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1976 |
| Grant date | Jul 22, 1980 |
| Priority date | — |
| Expiry date | Sep 22, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2208/0053
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A balanced, closed cycle silicon refinery system has been developed for producing electronic grade silicon from industrial grade silicon. Impurities comprising approximately 1% of the industrial grade silicon are removed in the refinery system to produce the purified silicon, while only a relatively small percentage of make-up chemicals are added to the system. In the refinery, hydrogen chloride is reacted with the impure silicon in a halide reactor to provide trichlorosilane and silicon tetrachloride and hydrogen. The trichlorosilane and/or silicon tetrachloride are passed through purification means, and then reacted with the hydrogen from the halide reactor in a fluidized bed reactor to produce the purified silicon and an effluent comprised of unreacted trichlorosilane, silicon tetrachloride, hydrogen, and the by-product hydrogen chloride. These materials are passed through a separator and the trichlorosilane and silicon tetrachloride and hydrogen are returned to the silicon reactor while the hydrogen chloride is returned to the halide reactor to be reacted with additional industrial grade silicon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.