Rare earth elements

Introduction 

• Rare Earth Elements or Rare Earth Metals are a set of 17 chemical elements in the periodic table the 15 lanthanides, plus scandium and yttrium.
• The 17 Rare Earths are cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), promethium (Pm), samarium (Sm), scandium (Sc), terbium (Tb), thulium (Tm), ytterbium (Yb), and yttrium (Y).
• 
  They tend to occur in the same ore deposits as the lanthanides, and have similar chemical properties. One of the Rare Earths, promethium, is radioactive.
• According to the Rare Earth Technology Alliance (RETA), the estimated size of the Rare Earth sector is between $10 billion and $15 billion.
• About 100,000-110,000 tonnes of Rare Earth elements are produced annually around the world.
• Rare earth minerals are not rare, they are commonly found in the earth’s crust. These metals are called rare because of the difficulties involved in extracting metals from the ore. The rare earth metals rarely occur in pure form. The costs involved in mining the rare earth metals is very high.
  

Reserve of Rare earth elements around world

• The total world reserves are estimated at 121 million tonnes of rare earth oxides (REO) of which China alone accounts for 44 million tonnes 
• India is also blessed with some crucial rare earth minerals like zirconium, neodymium etc. Due to radioactivity of monazite sands, Indian Rare Earths Ltd under the Department of Atomic Energy is the sole producer of rare earth compounds. This could contribute to Indian export markets if utilized properly.
• Other country like Australia, Russia, Vietnam, Brazil, Thailand etc. also have rare earth minerals.

Use of Rare earth elements

• Rare Earth elements are important in technologies of consumer electronics, computers and networks, communications, clean energy, advanced transportation, healthcare, environmental mitigation, and national defence, among others.
• Due to their unique magnetic, luminescent, and electrochemical properties, they help in technologies perform with reduced weight, reduced emissions, and energy consumption; therefore give them greater efficiency, performance, miniaturization, speed, durability, and thermal stability.
• Scandium is used in televisions and fluorescent lamps, and yttrium is used in drugs to treat rheumatoid arthritis and cancer.
• Rare Earth elements are used in space shuttle components, jet engine turbines, and drones.
• Its usage range from daily use (e.g., lighter flints, glass polishing mediums, car alternators) to high-end technology (lasers, magnets, batteries, fibre-optic telecommunication cables).
•  Cerium, the most abundant Rare Earth element, is essential to NASA’s Space Shuttle Programme.
• 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.

Sources of Rare earth elements

• Bastnaesite: A fluorocarbonate which occurs in carbonatites and related igneous rocks.
• Xenotime (yttrium phosphate): Commonly found in mineral sand deposits.
• Loparite: Occurs in alkaline igneous rocks and monazite (a phosphate).
• In India, monazite is the principal source of rare earths and thorium.
• They are usually found within other minerals in low concentrations that are not economically exploitable.
• Producing REE from mineral sands is cheap, as it comes as a by-product of industrial mineral mining.
• Found in the waste tailings of old mining projects.

Rare earth elements in India

• Geologically the entire landmass around the Indian Ocean contains REEs in the surrounding rocks.
• The entire coastline of the Indian Ocean is enriched in black colour mineral sands containing REEs.
• Monazite mineral in association with other minerals such as ilmenite, rutile, zircon, etc. in the beach sands and inland placer deposits are the main source of REE in India.

Importance rare earth elementss for India

• Rare earth minerals are very crucial for India in order to reduce the energy burden. It is an important component in the manufacture of hybrid vehicles, fuel cells and LEDs.
• It is indispensable in the manufacture of advance defence equipment.
• Essential for purifying the rivers flowing across the country.
• It is used in the manufacture of mobile phones, computers, digital networks, optical fibre cables and other IT gadgets which would help in our Digital India programme.
• Challenge in front of India regarding rare earth elements.
• The separation of the individual elements.
• Eradicating REE substances from discarded products is difficult and costly.
• The price pressure in establishing the downstream sector.
• Unequal distribution of individual rare earths in ores.
• The imbalance between supply and demand of rare earths results in large fluctuations in the cost of individual rare earths.
• There is a wide difference in the price of LREE and HREE.
• Extraction and mining of rare earth metals involves land-use exploitation, environmental damage, and ecological burden.
• Increased carbon emissions into the atmosphere and toxins into the ground.
• Damaging to the health of several ecosystems including humans.

Solution to tackle challenges regarding rare earth element

• The feasibility of exploring some other non-radioactive minerals need to be accelerated in public-private partnership manner.
• Need for strengthening of exploration expertise with modern concepts and tools including remote sensing capabilities.
• REE metals extraction techniques and facilities have to be pooled and the gap in the areas needs to be identified.
• Recycling technologies of REE containing products need to be developed on commercial scale.
• Need to identify new applications for the REE and use it as a substitute for the scarce or critical rare earths used in various applications.
• Needs to adopt optimized market strategies for a sustainable rare-earth industry.
• Needs to invest in a research and development programme in the area of Development of environment- friendly methods for the extraction and processing.