Separation of thorium and rare earth values from fluoride concentrates thereof
US4954293A · kind A · utility
16Cited by
8References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1988 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Nov 28, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01F17/235
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Thorium and rare earth values are separated from a fluoride concentrate thereof, by decomposing such concentrate with aqueous sodium hydroxide under conditions such that the amount of sodium hydroxide is at least 1.4 times the stoichiometric amount and the initial sodium hydroxide/water ratio in the medium of decomposition ranges from 1 to 40% by weight, whereby a precipitate of thorium hydroxide and rare earth hydroxides is produced, together with a solution of sodium fluoride, and then separating the NaF solution therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.