Abstract

In temperature and tropical regions, Rare Earth Elements (REE)s-bearing minerals abundant in particular igneous rocks normally decompose to REE3+ throughout chemical weathering then absorbs on the surface of weathered rock forming minerals and form ion-adsorption clay REE deposits. Due to obtainability of REEs in ion-exchangeable phases in such deposits, simple diluted electrolyte solution such as Ammonium Sulphate can extract significant amount of REEs at ambient temperature. Through different types of leaching methods can be utilized which are heap, tank/pool, and in-situ leaching methods, in-situ leach mining is the dominating technology now cause of more efficiency and less environmental impacts. Later on, more pured REE solutions can be achieved by using advanced techniques such as solvent extraction.