Selective separation of thorium from rare earth elements liquor during the alkaline processing of Egyptian monazite concentrate

Purification of Carrier-Free 47Sc of Biomedical Interest: Selective Separation Study from natCa(n,γ)

47Sc for theranostic medical applications was produced from the neutron activation of a natural calcium target. Liquid–liquid extraction for separation of the 47Sc radioisotope from 47Ca was carried out with the extractant Cyanex 272 ((2,4,4-trimethylpentyl) phosphinic acid). The effects of various extraction parameters on the extraction efficiency and separation of the two radionuclides were investigated, including the extraction time, pH, metal ion concentrations, extractant concentration, diluent type, and phase ratio. It was shown that the extraction yield of the 47Sc radioisotope with the proposed procedure is about 90%, with a fast separation time of 10 min, at pH 1.8 (0.01 M HCl), and with low E (1%) for 47Ca and high separation factors. The stripping % of the loaded 47Sc isotope was about 99.2% using 0.4 M oxalic acid solution with a purity of 99.9%.

Sponge-like Ca-alginate/Lix-84 beads for selective separation of Mo(VI) from some rare earth elements

In this investigation, a novel alginate complex was developed for the selective separation of molybdenum (Mo(VI)) ions from some rare earth elements (REEs). In this regard, alginate as a natural polysaccharide was impregnated and modified with 2-hydroxy-5-nonylacetophenone oxime (Lix-84) and characterized using FT-IR, TGA/DTA and SEM-EDX. The relation between medium acidity, adsorption kinetics, sorbent dose, isotherm models, temperature and Mo(VI) recovery was investigated. It was concluded that the impregnation stage promoted the Mo(VI) separation. The kinetics and isotherm data were well-fitted and matched with the pseudo-first-order model and Langmuir isotherm model; respectively. The Langmuir maximum adsorption capacity of Mo(VI) reached 72.2 mg/g. The developed material showed excellent separation performance towards Mo ions over the investigated REEs. The desorption and recovery of the loaded Mo(VI) ions were achieved using 1.0 M HCl. Reutilization of Alg/Lix-84 was confirmed up to three adsorption-desorption cycles with no damage of the beads as proved with SEM analysis. The adsorption mechanism of molybdenum onto Alg/Lix-84 was elucidated through FTIR and XPS measurements and was found to be governed by both electrostatic interaction and ion exchange. Therefore, the developed material has a promising potential for the selective separation of molybdenum from REEs-containing solution.

Novel nano network trigonal prismatic Ba2CoO4-deficient BaCoO3 for high-affinity sorption of radiolanthanide elements of biomedical applications: synthesis and sorption studies

Nano trigonal prismatic Ba₂CoO₄ with hierarchical structure and deficient BaCoO₃ with columnar structure have been prepared at low temperatures (400 [BC4] and 500 [BC5]) °C/3h using green method. X-ray diffraction (XRD) results demonstrate the presence of enriched Ba₂CoO₄ phase at 400 °C and multiphase structures: BaCoO₃, BaCoO_3-δ, and Co₃O₄ with a decrease in the amount of Ba₂CoO₄ at 500 °C. The prepared powders are characterized by a high specific surface area (SSA) values which are reflected to the mode of synthesis that leads to produce materials with massive active sites. The SSA of BC4 is higher than that of BC5 which can be correlated to the difference in the microstructure analysis of BC4 and BC5 as given from scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) studies. Electron spin resonance (ESR) spectroscopy as an effective method for the characterization of vacancy-rich nanostructures indicates that the presence of oxygen vacancies is related mainly to BaCoO₃, BaCoO_3-δ, and Co₃O₄ phases while the effective oxygen vacancies is in BaCoO₃ and BaCoO_3-δ. The nanocrystalline structures of BC4 and BC5 as novel nano-adsorbents are the first time to be tested. Production of Gd radioisotopes through ^natGd(n,γ)^153,159,161Gd and carrier-free ¹⁶¹Tb through ¹⁶⁰Gd(n,γ,) ¹⁶¹Gd [Formula: see text] ¹⁶¹Tb are achieved at 2nd Egyptian nuclear research reactor (ETRR-2). Preliminary sorption study of Gd radioisotopes (represent the lanthanide elements) shows a promising material for the application in the separation and removal of lanthanide elements. The results demonstrated that the fast interaction and efficient sorption of lanthanides ions are based on the novel synthesized nanomaterial that can be considered for the upscale application in this field.

Efficient trace-scale extraction method of reactor produced 199Au adequate for nuclear medicine applications

Production of no carrier-added (NCA) 199Au through natPt(n, γ) reaction and subsequent purification using liquid-liquid extraction from other radioisotopes is studied in the context of theranostic application. Comparative separation of NCA 199Au after dissolution of activated Pt target using three Cyanex compounds (Cyanex-272, Cyanex-302 and Cyanex-923) is evaluated. The extraction process is optimized in terms of the type of extractant, the concentration of extractant, extraction time and aqueous media (HNO3, NH4OH). Among these extractants, the Cynaex-923 is efficient and promising for rapid separation and production of NCA 199Au from HNO3 by high extraction %. Selective extraction of 199Au from other Pt and Ir radioisotopes is observed. High recovery of 199Au was obtained in the case of Cyanex-923 using 0.05 M thiourea dissolved in HCl or 2 M NaOH. Our results find the Cyanex-923 as a promising extractant for efficient separation of 199Au from irradiated Pt target with high yield (99%).