Rare Earth Permanent Magnets (REPMs)
Context:
The Union Cabinet approved a new first-of-its-kind scheme to manufacture Rare Earth Permanent Magnets (REPM) in India
This is a major initiative by the Government of India to enhance self-reliance in this critical sector.
Composition and Properties:
The two primary commercial types are
Neodymium-Iron-Boron (NdFeB)
Samarium Cobalt (SmCo).
NdFeB Composition:
These are the strongest commercial magnets available
These magnets are composed of approximately 30% rare earth material(Neodymium and Praseodymium), 69% Iron, and 1% Boron by weight.
NdFeB magnets are irreplaceable in clean-energy technologies due to performance advantages
SmCo (Samarium–Cobalt) magnets
They have superior high-temperature performance
Significance of Rare Earth Magnets
They have the highest energy density and provide unmatched power-to-weight ratio. This enables:
compact, lightweight motors
high-efficiency generators
high-speed, miniature actuators and sensors
Global Distribution:
The supply chain is heavily concentrated in China, which controls 58% of mining, 89% of separation, 90% of metal refining, and 92% of magnet manufacturing.
Major Deposits:
The Bayan Obo mine (China) is the largest source.
The U.S. has high-quality deposits like Mountain Pass (California) but lacks domestic separation capacity for HREs.
Applications:
Clean Energy:
They are essential for Permanent Magnet Synchronous Generators (PMSG) in offshore wind turbines and traction motors in Electric Vehicles (EVs).
Consumer & Industrial:
They are also used in hard disk drives (voice coil motors), smartphones (speakers), MRI machines, and industrial motors.
Aerospace, Defense, High-Temperature Uses