Process for producing high purity tantalum oxide
US4537750A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1984 |
| Grant date | Aug 27, 1985 |
| Priority date | — |
| Expiry date | Feb 29, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01G35/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process is disclosed for producing high purity tantalum oxide from impure tantalum oxide. The starting tantalum oxide is dissolved in a hydrofluoric acid solution and insolubles are removed. The hydrofluoric acid solution containing the tantalum values is adjusted to a pH of from about 6.0 to about 8.0 with a base to precipitate tantalum which is separated from the mother liquor. The tantalum precipitate is then dissolved in an oxalic acid solution, the pH adjusted to from about 5.1 to about 5.5, and the resulting solution digested to precipitate a high purity tantalum compound which is separated. The high purity tantalum compound is then digested in hydrochloric acid to dissolve the compound and then precipitate pure optical grade tantalum oxide which is then separated from its mother liquor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.