A critical review on solvent extraction of rare earths from aqueous solutions

Titanium alkylphosphate functionalised mesoporous silica for enhanced uptake of rare-earth ions

“…The second system comprised a 1 mM equimolar mixture of Nd and Dy (with 5 M NH 4 NO 3 ), sorption was studied as a function of the pH in the range of 1 to 5. The pH was adjusted with 1 M HNO 3 . Desorption experiments were conducted by first loading the materials with metals at appropriate equilibrium pH.…”

“…Finally, after centrifugation, the supernatant was taken for metal analysis. The desorption solution used here were water, 0.01 M HNO 3 and 0.1 M HNO 3 . Cyclic sorption-desorption was performed for five cycles.…”

“…However, the separation of complex mixtures of REEs remains challenging owing to the similarity of their chemical properties. 3,4 The SX process involves the use of organic extractants which transfer the REE ions from the aqueous to the organic phase. 5 Usually, the organic phase consists of a diluent (kerosene) to dissolve the extractant, reduce the viscosity of the loaded organic phase and facilitate the hydrodynamics of the extracted species.…”

“…6,7 The neutral REE-nitrate complexes are coordinated by the phosphoryl group in TBP, yielding an extractable complex (Eq. 1): 3 The extraction of REEs must be carried out at high nitrate salt concentrations (often > 6 M) to shift the equilibrium in Eq. 1 to the right.…”

Characterization of Rare Earth Element Ores with High Spatial Resolution Scanning Electron Microscopy

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Rare earth elements (RREs) include the fifteen lanthanides plus scandium and yttrium [1]. Because of their prevalence in renewable energy devices and high-end electronics, REEs become increasingly significant for the advancement of technology and energy saving devices [2].

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