Abstract:
Rare earth elements (REEs) are widely attracting global attention due to their crucial role in the modern lifestyle, especially in the industrial advancement towards a green economy through renewable technologies. This particular group of metals consists of the 15 lanthanides, yttrium (Y), and scandium (Sc). There are two subgroups, namely light rare earth elements (LREEs) from lanthanum (La) to europium (Eu) and heavy rare earth elements (HREEs) from gadolinium (Gd) to lutetium (Lu) and Y (Fig. 1a). Generally, LREEs are more abundant in the mineral deposits when compared to more priced HREEs [1].