Title: Solvent extraction system for REE and Sc separation and recovery
Responsible partner: VTT
Location of pilot: Finland
The pilot composes a bench-scale REE extraction extraction set-up which operated in semi-batch or continuously. The unit consists of a battery of 12 mixer-settlers, which can be used in extraction/scrub/strip depending on the system requirements. The flow rate (aqueous or organic) is 1-80 mL/min. The mixer volume is 270 mL and the settler volume is 1050 mL. Both aqueous and organic layers can be recycled. Cation exchangers (carboxylic acids, phosphorous acids), chelating exchangers (such as LIX), or solvating extractants (TOPO, Cyanex 923) can be used as reagents in the system. The main target is to produce a REE concentrate and to study the potential to maximise the value of the concentrate (decrease impurities by eliminating Zn, Fe, etc.). The secondary target is to study the potential of scandium recovery. The REE are precipitated as oxalates, and further transformed into oxides by calcination.
Picture: SX setup(left), REE precipitation circuit (right).
Responsible contact: Antero.Laitinen@vtt.fi