| Autor: |
Larrinaga WB; Department of Chemistry and Biochemistry, The University of Tampa, 401 West Kennedy Boulevard, Tampa, Florida 33606, United States., Lake BJ; Department of Chemistry and Biochemistry, The University of Tampa, 401 West Kennedy Boulevard, Tampa, Florida 33606, United States., Pacanowski VD; Department of Chemistry and Biochemistry, The University of Tampa, 401 West Kennedy Boulevard, Tampa, Florida 33606, United States., Patterson MG; Department of Chemistry and Biochemistry, The University of Tampa, 401 West Kennedy Boulevard, Tampa, Florida 33606, United States., Hudson M; Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States., Carlson FM; Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States., Heselschwerdt G; Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States., Balboa S; Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States., Biros SM; Department of Chemistry, Grand Valley State University, 1 Campus Drive, Allendale, Michigan 49401, United States., Werner EJ; Department of Chemistry and Biochemistry, The University of Tampa, 401 West Kennedy Boulevard, Tampa, Florida 33606, United States. |
| Abstrakt: |
One of the major challenges in processing rare-earth element (REE) materials arises from the large amounts of radioactive thorium (Th) that are often found within REE minerals, encouraging enhanced metal separation procedures. We report here a study aimed at developing improved systems for REE processing with the goal of efficient extraction of Th(IV) from acidic solution. A tripodal ligand, TRPN-CMPO-Ph, was prepared that utilizes carbamoylmethylphosphine oxide (CMPO) chelators tethered to a tris(3-aminopropyl)amine (TRPN) capping scaffold. The ligand and its metal complexes were characterized by using elemental analysis, NMR, Fourier transform infrared spectroscopy, mass spectrometry, and luminescence spectroscopy. Using a liquid-liquid metal extraction protocol, TRPN-CMPO-Ph selectively extracts Th(IV) at an efficiency of 79% from a mixture of Th(IV), UO 2 2+ , and all rare-earth metal cations (except promethium) dissolved in nitric acid into an organic solvent. Th(IV) extraction selectivity is maintained upon extraction from a mixture that approximates a typical monazite leach solution containing several relevant lanthanide ions, including two ions at higher concentration relative to Th(IV). Comparative studies with a tris(2-aminoethyl)amine (TREN)-capped derivative are presented and support the need for a larger TRPN capping scaffold in achieving Th(IV) extraction selectivity. |
