Dry conversion of high purity ultrafine silicon powder to densified pellet form for silicon melting applications
US7175685B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2003 |
| Grant date | Feb 13, 2007 |
| Priority date | — |
| Expiry date | Jan 1, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B29/06
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A bulk silicon material for making silicon ingots, consisting of silicon pellets, and a method for making the pellets from an agglomerate-free source of high purity silicon powder by feeding a controlled amount of silicon powder that is free of intentional additives and binders into a pellet die, and dry compacting the powder at ambient temperature with pressure to produce a pellet that has a density of about 50–75% of the theoretical density of elemental silicon, a weight within a range of about 1.0 gram to about 3.0 grams and preferably of about 2.3 grams, a diameter in the range of 10 mm to 20 mm and preferably of about 14 mm, and a height in the range of 5 mm to 15 mm and preferably of about 10 mm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.