Process for recovering tungsten from tungsten bearing material containing arsenic
US4741886A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1986 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Oct 24, 2006 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01G41/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process is disclosed for recovering tungsten from tungsten bearing material containing arsenic. The process involves adjusting a water slurry of the material to a pH of less than about 4 with an acid to solubilize the major portion of the tungsten, adding an insoluble ferric compound to the slurry to form a two phase system in which the solid phase contains the major portion of the arsenic and of any phosphorus which may be present, and a solution phase containing the major portion of the tungsten. After separation of the solid from the solution, the solution is adjusted to a pH of less than about 2 with an acid and a suffficient amount of hexamethylenetetramine is added to the solution to precipitate the major portion of the tungsten, followed by separating the precipitate from the resulting liquor. The solid phase containing the arsenic and phosphorus, if any, can be contacted with water and a soluble ferric salt to produce a treated solid which passes the EP toxicity test.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.