Recovery of rare earths, lithium, and fluorine from rare earth molten salt electrolytic slag by mineral phase reconstruction combined with vacuum distillation

Disposal Strategy of Ion-Adsorption Rare Earth Elements Low-Level Radioactive Residues: Reduction Emission and Recovery for Aluminum and Uranium by Alkaline and Alkalescent Media

“…Correspondingly, the content of REEs in the residues increased from 0.88 to 3.60 wt % (enrichment ratio of 4). The obtained REEs-ER could be then disposed with conventional HCl dissolution method, , resulting in the RECl 3 extraction solution that could be recycled into an extraction process to meet the requirements of sustainable development.…”

“…Rare earth elements (REEs), as a strategic resource, have drawn great attention due to their significant applications in high-tech fields. − Ion-adsorption rare earths ore (IREO) contributes approximately 80% to the global supply of REEs resources . As associated natural radioactive elements, such as uranium (U) and Thorium (Th), their enrichment , in IREO residues is followed throughout the production process of IREO. , As reported, the total radionuclide activity of IREO residues was approximately 5–300 Bq/g, which was higher than the exemption level (>1 Bq/g, GB 27742-2011) and belonged to low-level radioactive waste (<400 Bq/g, GB 02013-2017), named as ion-adsorption rare earth elements low-level radioactive residues (IREEs-LRR), leading to an increased risk of environmental pollution and health hazards. , …”

Recovery of rare earths and lithium from rare earth molten salt electrolytic slag by lime transformation, co-leaching and stepwise precipitation

“…The molten salt electrolysis process is widely employed for the preparation of different reactive metal elements and their alloys due to its advantages of high product purity, low cost, and easy implementation of continuous operation. Currently, rare earth metals and their alloys are primarily produced through the molten salt electrolysis process under fluoride system (REF3-LiF-RE2O3) or chloride system (RECl3) (Sun et al, 2022;Yang et al, 2019;Feng et al, 2023;Gu et al, 2017;Chen et al, 2021;Lai et al, 2023). Presently, considering the benefits of a more stable electrolyte composition with better hydrolysis resistance, higher current efficiency and rare earth yield along with being more environmentally friendly; the fluoride molten salts system (REF3-LiF-RE2O3) is more commonly used in rare earth metal molten-salt electrolytic processes compared to the RECl3 system Liu et al, 2023;Liang et al, 2018;Prince et al, 2021).…”

Microwave-assisted atmospheric alkaline leaching process and leaching kinetics of rare earth melt electrolysis slag

“…The RMES was roasted with sodium carbonate at 700 °C for 2 h, which converted the contained rare-earth fluoride into a rare-earth oxide and achieved a rare-earth leaching rate of 99 %. Lai et al [ 13 ] reconstructed the mineral phase of the RMES by adding LiOH·H 2 O and combined it with vacuum distillation to recover REEs through subsequent roasting at 600 °C and distillation at 1100 °C. Hu et al [ 14 ] and Wang et al [ 15 ] treated RMES with nitric acid and sulfuric acid calcination, respectively, and successfully converted fluorinated REEs into soluble nitric acid/sulfuric acid REEs at around 250 °C at a conversion rate of >95 %.…”