Interaction of high energy protons in nuclear emulsions loaded with b 10 and LiF

An experiment is proposed to expose nuclear emulsions loaded with B{sup 10} and LiF to high energy protons at 100 GeV, 150 GeV and 200 GeV. The purposes are: (i) to measure the total cross-sections at these incident energies, (ii) to investigate charged multiplicity as a function of energy, (iii) to investigate the angular distribution and development of hadron showers in collisions of protons with nuclei

Purification of Uranium from acidic liquid wastes and ore solutions by selective hybrid materials

International audienc

The effect of pore diameter in the arrangement of chelating species grafted onto silica surfaces with application to uranium extraction

International audienc

Selective extraction of rare earth elements from phosphoric acid by ion exchange resins

International audienceliterature review has been carried out to identify techniques allowing rare earth element recovery from phosphoric acid. These metals are present at low concentrations in solutions obtained after the attack of phosphate ores by sulfuric acid. The strongly acidic and complexing nature of this medium, as well as the presence of other traces metallic natural impurities (including iron and uranium), require the development of a particularly effective and robust process for the selective recovery of rare earth elements. Commercial solid supports are proposed to be tested, , the most promising seem to be those having functional groups as aminophosphonic acid (Tulsion CH-93, Purolite S940, Amberlite IRC-747, Lewatit TP-260), or as phosphoric acid (Lewatit VP OC 1026), or as phosphonic (Monophos, Diaion CRP200) or as diphosphonic, diphosphoric acid (Diphonix, Actinide-CU). A laboratory protocol test is described and carried out to explore the behavior of every main element with some of these resins in the phosphoric acid medium

Élaboration de silices hybrides pour la récupération de l'uranium

International audienc

Uranium adsorption from sulfuric acid media using silica materials functionalised with amide and phosphorous ligands

International audienceVarious functionalised silica materials have been investigated as uranium extractants from sulfuric acid solutions. Silica was grafted with zero, one or two amido and phosphonate groups either directly or by peptide coupling. The role of the residual functions (silanol, amine and amide) was evaluated. Our results show that the uranium extraction efficiency of materials bearing residual Ol or Am groups may be affected by the presence of molybdenum. Comparing the performance of materials with different numbers of phosphonic acids on the phosphonate group revealed that only those with a monoacid function extract uranium efficiently. Among these materials, those with a diamido phosphonate ligand were more efficient than those with a monoamido phosphonate function. Adjusting the length and steric hindrance of the alkyls chains of the amido and the phosphonate group, the best extraction capacity and selectivity versus iron was achieved with a butyl group on the phosphonate and an ethyl group on the ternary amide of the diamido phosphonate ligand. Finally, the (ligand)-(U) ratio was found not to vary with bridge length between the carbamoyl monophosphonate extracting group and the amidopropyl anchor to the silica, suggesting that the extraction mechanism remains unchanged