LREEs

Light rare earth elements (LREEs) are the lighter portion of the lanthanide series. The group typically includes lanthanum, cerium, praseodymium, neodymium, and samarium; europium is sometimes included in the LREE category depending on the classification used. Like other lanthanides, LREEs have similar chemical properties and commonly occur together in minerals such as bastnäsite and monazite.

LREEs are relatively abundant in the Earth's crust but are usually dispersed and occur at low concentrations, often in association with silicate minerals. Major ore minerals include bastnäsite and monazite. Production has historically been dominated by a few countries, with China accounting for a large share of refining capacity and supply; other producers include Australia, the United States, Myanmar, India, and several African and European countries. The mining and processing of LREEs can involve environmental and regulatory challenges due to thorium content in some ores and the energy-intensive separation procedures required to obtain individual elements.

Chemically, LREEs typically:

- Exist in the trivalent oxidation state in minerals.

- Have very similar ionic radii, making their separation a technical challenge.

- Are often separated by solvent extraction and ion-exchange methods to yield individual elements.

Applications of LREEs are diverse. Neodymium and praseodymium are key components of Nd-Fe-B permanent magnets used in motors and electronics. Cerium and lanthanum are widely used in catalysts, polishing powders, glass additives, and petroleum refining. Europium and terbium, though present in smaller amounts, are important in phosphors for lighting and display technologies.

Demand for LREEs is linked to energy, electronics, and automotive technologies, with ongoing efforts to diversify supply, improve recycling, and mitigate environmental impacts of mining and processing.