Liquid/liquid extraction/purification of impure solutions of rare earth values
US4726938A · kind A · utility
30Cited by
4References
32Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1986 |
| Grant date | Feb 23, 1988 |
| Priority date | — |
| Expiry date | Jan 15, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/14
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Aqueous nitric solutions of salts of at least one rare earth, and containing contaminating amounts of at least one alkaline earth cation, e.g., calcium, barium and/or radium, are conveniently purified by liquid/liquid extracting same with an organic phase which comprises a polyether extractant for said at least one alkaline earth cation, e.g., a crown ether, and whereby said at least one alkaline earth cation is selectively transferred into said organic phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.