Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5639433 | Extraction of rare earth elements using alkyl phosphinic acid or salt/alkyl or aryl phosphonic acid or ester blends as extractant | Hengli Ma | 1997-06-17 |
| 5622679 | Extraction of rare earth elements using alkyl phosphinic acid or salt/tetraalkylammonium salt as extractant | Hengli Ma | 1997-04-22 |