Rare earth elements form a series of seventeen chemically similar metals and are generally classified into three categories: light, medium and heavy. They are found in distinct ore bodies and have unique chemical, magnetic and luminescent properties. This means that the processing route for the recovery of rare earth metals is project specific. Light rare earths are predominantly produced in the form of bastnasite ((REE)CO3F) where it is a by-product of iron ore mining. Other rare earth mineral products include monazite and xenotime ((REE)PO4 dimorphs), which are usually obtained as by-products of titanium minerals and tin production.
Due to their unique characteristics, such as magnetic and optical properties, rare earths are used in a diverse range of applications including electronics, ceramics, magnets, batteries, steel alloys and as catalysts.