rare earth permanent magnets: raw materials, magnets...
TRANSCRIPT
Rare Earth Permanent Magnets:
Raw Materials, Magnets and
Opportunities
S. R. Trout
Source: Getty ImagesSource: Mike Coey, Trinity College
Outline
• Raw Materials
• Rare Earth Magnets
• Applications
• Final Thoughts
Raw Materials
Sc Y La
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Raw Materials
• Ores contain all rare earths except Pm
• There is no shortage of ore
– Most rare earths are not rare
• Most ores are rich in Ce, La, Nd and Pr
• The rare earths are chemically very similar
• Producers try to balance supply and demand
Raw Materials
• Ores contain all rare earths except Pm
• There is no shortage of ore
– Most rare earths are not rare
• Most ores are rich in Ce, La, Nd and Pr
• The rare earths are chemically very similar
• Producers try to balance supply and demand
– And are rarely successful!
Bayan Obo mine ,near Baotou, China
Photo from Google Earth
1 km
Mountain Pass, CAPhoto from Molycorp
~1 km
Raw Materials
Raw Materials
Source: Roskill
010,00020,00030,00040,00050,00060,000
70,00080,00090,000
100,000110,000120,000130,000
1956 1966 1976 1986 1996 2006
Other USA China
Raw MaterialsP
rod
uct
ion
, met
ric
ton
s
Source: U.S. Geological Survey
Raw Materials
• Active mines– China
• Baotou
• Ionic Ores
• Mines in transition– USA
• Mountain Pass, CA
• Identified deposits– Australia
• Mt. Weld
• Nolan’s Bore
– Canada• Hoidas Lake
• Thor Lake
– India
– Brazil
– Vietnam
– Russia
– Greenland
Raw Materials
Source: Dudley Kingsnorth, IMCOA, 2009
Raw Materials
• Lack of viable ores
– Most rare earths are not rare
• Shortage of Neodymium
– A self-regulating market• Price
• Design
• Application
• Dysprosium and Terbium
– Constrained
• Abrupt changes are extremely disruptive
– Upsets balance
– Capital intensive industry
– Lengthy recovery
Issues
Rare Earth Magnets
• Sources of magnetic flux– Coil of wire with current flowing
• + easy to modulate• - heat and energy
– Superconductors• + huge steady magnetic fields• - cryogenic fluids
– Permanent magnets• Ceramics (Hard ferrites), Alnico, SmCo and NdFeB• + always on, no heat or energy• - temperature
Rare Earth Magnets
Materials
• Sm-Co– SmCo5
– 2-17, Sm2(Co,Fe,Cu,Zr/Hf)17
• Nd-Fe-B– (Nd,Dy)2(Fe, Co)14B
Questions
• When?
• Who?
• Where used?
• Speed of implementation?
Rare Earth Magnets
Nd2-xDyxFe14B Nd2Fe14B
Source: NeomaxIncreasing x
Increasing x
Rare Earth Magnets
• Unfinished business
– The Hci of Nd-Fe-B• Why do Dy and Tb increase Hci?
– We need a better story
• Controlling β, the temp. coefficient of Hci
• Wiser use of Dy and Tb
– Recycling, reuse
– Lower cost
Rare Earth Magnets
• Hard drive
– Voice Coil Motor (VCM)
– Spindle motors
ApplicationsSource: Western Digital
Rare Earth Magnets
• Automotive
– Current
Applications
Cruise Control
Mirror MotorsTailgate
MotorDoor Lock
MotorFour
Wheel Steering
Anti-skidSensor and
Motor
WindowLift
Motor
SuspensionSystem
FuelPumpMotor
Seat Belt
MotorSeat
AdjustMotors Antenna
LiftMotor
TractionControl
Heater-A/C Blower Throttle
and Crankshaft
PositionSensors
WindshieldWiperMotor
StarterMotor
CoolantFan
Motor
IgnitionSystems
HeadlightDoor
Motor
Economy and
PollutionControl
LiquidLevel
Indicators
WindshieldWasherPump
Gauges
CDPlayer
HeadRest
MotorSunRoof
Motor
ElectricPower
Steering and Sensor
Lumbar Support
AutomaticTemperature
Control
DoorGasket
DefoggerMotor
Speakers
Source: Magnequench
Rare Earth Magnets
• Automotive
– Hybrids
Applications
Source: Toyota
Rare Earth Magnets
• Wind Turbine
– Magnet vs. asynchronous
– One tonne of magnet per turbine
– The future?
ApplicationsSource: Vestas AS
Rare Earth Magnets
The Dy Issue
Source: MagnequenchHci (kOe)
(BH
) max
(MG
Oe)
Final Thoughts
Raw Materials
• Issues– Dy and Tb
– Sudden changes
• Opportunities– Green technologies
• Magnets
• Ni-metal hydride batteries
• Lighting phosphors
Rare Earth Magnets
• Issues– Dy and Tb
• What do they really do?
• How can we use less of them?
– Limited production outside China
• Opportunities– Hybrid vehicles
– Wind turbines
– Recycling