Selective dissolution and separation of lanthanides and actinides from spent nuclear fuel using inorganic salt solutions: A sustainable approach
Efficient utilization of uranium resources and minimization of nuclear waste are critical challenges for the sustainable development of nuclear energy. The separation of actinides (An) from lanthanides (Ln) is essential to reduce the impact of neutron poisons and enhance the efficiency of Partitioning & Transmutation (P&T) processes. In this study, we propose the use of a concentrated AlCl 3 solution as a selective leaching agent to separate Ln from An in spent nuclear fuel (SNF). At a mass ratio of 1:15, the AlCl 3 solution effectively dissolves nearly 100 % of lanthanide oxides from simulated SNF at 75 °C, while the coexisting actinide oxides remain largely insoluble. The high separation factors between Ln 2 O 3 and AnO 2 (average of 1630 for Ln/U and 490 for Ln/Th) provide a novel and efficient approach for the selective separation of lanthanides from SNF. The lanthanides are subsequently recovered through oxalic acid precipitation and calcination to produce Ln 2 O 3 . Based on our characterization results, the primary driving force for the dissolution of Ln 2 O 3 is the acidity of the H 2 O-AlCl 3 system, with the lattice energies of oxides identified as the key factor affecting the differential dissolution of Ln(III) and U/Th with higher valent under identical conditions. This selective dissolution and separation process using AlCl 3 solution presents a highly efficient method for the removal of lanthanides from SNF and improves the utilization of nuclear fission products. With its mild operating conditions and reduced environmental impact, this method offers a promising approach for the recovery of rare earth elements from nuclear waste and other secondary resources.
危险品化学品经营许可证（带存储）