Rare earth elements are a set of seventeen chemical elements which include fifteen lanthanides plus scandium and yttrium. All the 17 elements have similar chemical properties. In terms of their overall abundance in the Earth’s crust, the rare earth elements are not particularly rare. Cerium (Ce) is the most abundant and Thulium (Tm) is the rarest rare earths element. Promethium (Pm) is virtually absent, since it is radioactive with a short life-time.
Rare earths (RE) are actually found quite abundantly in the Earth’s crust, but termed ‘rare’ because they occur in minute quantities and a diffused state that makes it difficult as well as expensive to extract and process.
Applications of rare earths Metals
Rare earths metals are critical to many industries of the future. Theses 17 elements are necessary for making everything from nuclear reactors to flat-screen televisions, from smart phones to hybrid cars to solar panels.
Due to their distinctive properties, rare earth elements have several desirable properties that have use in a variety of high technology applications.
• They are important for manufacturing of key intermediates that are used in production of a number of green energy products such as hybrid cars, energy efficient lighting, fuel cells and windmills.
• Some of the intermediate industries that are dependent on rare earth elements are the glass industry, permanent magnet industry, phosphors used in lighting and display devices, catalysts for the oil refining industry, etc.
• Rare earth elements are also useful in a number of military and strategic systems. Neodymium-doped Yttrium Aluminium Garnet (NdYAG) lasers are used in range finding applications that are used in advanced weapon systems.
• Terfenol D, which is an alloy of terbium, iron and dysprosium, has unique properties and it is used in sonar and other acoustic applications.
• Rare earth oxides are mixed with Tungsten to improve its high temperature properties for welding, replacing thorium which was mildly hazardous to work with.