Context

• West Bengal gears up for rare earth mining in Purulia District.

About the news

• West Bengal is set to join India’s rare earth mining map with Geological Survey of India conducting advanced exploration in Purulia District, West Bengal.
• G2-level exploration is underway in two blocks one in Karbi Anglong district of Assam and the other in Purulia, West Bengal.
• Both blocks will be ready for auction in an year.

About Rare Earth Elements

• The Rare Earth Elements (REEs) are 17 metals in Group 3 of the Periodic Table comprising Lanthanide series elements and Scandium and Yttrium (due to similar physical properties and found in the same ores and deposits).
• Rare Earth Elements are important components in over 200 products, spanning applications in consumer electronics, electric vehicles, defence systems, and many more.
• Rare Earth Elements: Scandium, Yttrium and the 15 Lanthanides, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm)
• Other Rare Earth Minerals are samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu).

Types

• Based on the atomic weight, Rare Earth Elements are divided into two groups.
• Light REE’S:These are those with atomic numbers from 57 to 63 (La, Ce, Pr, Nd, Pm, Sm and Eu)
• Heavy REE’S: These are those with atomic numbers from 64 to 71 (Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu).
• Scandium and Yttrium, although light, have been placed with the heavy REEs group due to their similar chemical and physical properties.

Characteristics

• REEs are characterised by high density, high melting point, high conductivity and high thermal conductance.
• Rare Earth Elements share a trivalent charge (+3) and similar ionic radii, hence similar properties.

Sources

• The principal sources of REE are bastnaesite (a fluorocarbonate which occurs in carbonatites and related igneous rocks), xenotime (yttrium phosphate) commonly found in mineral sand deposits, loparite which occurs in alkaline igneous rocks and monazite (a phosphate).
• Several rare-earth minerals contain thorium and uranium in variable amounts, but they do not constitute essential components in the composition of the minerals.
• Cerium is the most abundant rare earth, approximately the same as that of Copper.

Significance

• Rare Earth Elements are very important for futuristic technology.
• They have wide applications in clean energy, high-end electronics, defence, etc with no equal substitutes.

Application of Rare Earth Elements

• Permanent magnet: Neodymium magnets (Nd-Fe-B magnets) are permanent magnets made of neodymium, iron and boron.
• They have the highest magnetic properties of all permanent magnets and can withstand temperatures as high as 230 degrees C.
• They are used in automobiles for anti-lock brakes, in computer hard disk drives, CD-ROMs, digital cameras, etc.
• These magnets are also used in a variety of conventional automotive subsystems, such as power steering, electric windows, power seats, and audio speakers.
• Electronics and Displays: Rare Earth Elements are used in high-technology devices such as smartphones, hard disks, digital cameras, fluorescent and light-emitting-diode lights, computer monitors and electronic displays. 
• Some rare earth elements have phosphorescent properties, which makes them to be used in the manufacture of flat television screens and computer monitors.
• Lanthanum makes up as much as 50 per cent of digital camera lenses, including cell phone cameras.
• Eu, Y, and Tb are used in the manufacturing of phosphors (substances that emit luminescence) to be used in many types of ray tubes and flat panel displays for screens that range in size from smartphone displays to stadium scoreboards.
• Erbium is used to make fibre optic cables and laser repeaters.
• Green Technologies: They play a critical role in green technologies such as wind turbines and electric vehicles that are going to support net zero carbon emissions goals.
• Nickel-metal hydride batteries are built with lanthanum-based alloys as anodes which are used in electric vehicles.
• Cerium-based catalysts are used in automotive catalytic converters.
• Lanthanum acts as a hydrogen absorber in rechargeable batteries and is an important element in hybrid car batteries.

Rare Earth Elements in India

• India is the fifth-largest rare earth resource globally, with significant deposits in the monazite minerals.
• Resources: There are around 13.07 million tonnes of REEs, mainly found in the monazite sand, which contains 55-60% total Rare Earth Elements oxide. These are found in:
• Coastal beach placer monazite sands of Andhra Pradesh, Odisha, Kerala, Tamil Nadu, Maharashtra and Gujarat.
• Inland placer deposits of Jharkhand, West Bengal and Tamil Nadu.
• Types: India contains mainly Light REEs while Heavy REEs are not available in extractable quantities.
• Only Neodymium and Praseodymium are available in India and are being extracted up to the 99.9 % purity level.

Mining

• Indian Rare Earth Limited (IREL) is a major player in mining and processing, producing rare earth compounds.
• Foreign collaboration: Toyotsu Rare Earths India Limited, Visakhapatnam (Toyota Tsusho Corporation, Japan with IREL) 

Initiatives by Government

• Initiatives like the setting up of a Rare Earth Theme Park and joint ventures aim to enhance India’s position in this critical industry.
• RE and Titanium Theme Park was developed by IREL to cater for the technologies developed by BARC.
• India is actively exploring collaborations, and initiatives such as Toyotsu Rare Earths India Limited in Visakhapatnam to enhance efforts to refine rare earths through foreign collaboration.
• Recently, a Carbonatite Deposit was found in Gujarat.
• IREL processing plants have been established in Ganjam, Odisha and Aluva, Kerala.