permanent magnets for energy applications part 2 stan trout august 11, 2014
TRANSCRIPT
Permanent Magnetsfor Energy Applications
Part 2Stan Trout
August 11, 2014
Permanent Magnets for Energy Applications Part 2• Rare Earths
– Basic facts– The crisis– Mines– Applications
• Magnet Recycling• Permanent Magnet Selection &
Specification• Case Studies• The Future
Rare Earths
Sc Y La
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
Rare Earths 101
• Ores contain all rare earths except Pm• The rare earths are chemically very similar• There is no shortage of ore for light RE’s
– Bastnasite & Monazite are the most common• Most ores are rich in Ce, La, Nd and Pr
– Not all rare earths are rare in the Earth• Magnetic, optical, electronic and catalytic
properties vary widely• The lanthanide contraction• Producers try to balance supply and
demand– And are rarely successful!
Dilbert, February 28, 2011
Critical Materials Institute
• DOE Program– $120 million, 5
years– National Labs– Academe– Industry
• Reduce criticality• CMI opened
officially on Sept. 10, 2013
Source: DOE Announcement May 2012
Recent RE Metal Prices
Source: U.S. Geological Survey
Two Confusing Points
• Analysis and Recovery, are not the same thing
• Balance– What is it?– Why it is important to the RE industry
and to customers
Rare Earth Analysis
Source: Castor, Resource Geology vol. 58, No. 4, 337-347 (2008)
The Castor Analysis
• Original report 1986, almost 30 years old
• First Mass Spec-ICP• A single sample• Widely quoted, sometimes abridged to
omit heavy RE’s• Widely believed to predict recovery
accurately– At best only an upper limit
Analysis vs. Recovery
Analysis• Goal: understand
composition• Scale: 10 gram• Digestion: complete
as possible• Separation: no
Recovery• Goal: sell into
marketplace• Scale: 1010 gram• Digestion: appropriate
for scale and market• Separation:
appropriate for market conditions
Balance• The attempt by each rare earth
processor to balance the available ore with the needs of the marketplace.
Source: Kingsnorth
Bayan Obo mine ,near Baotou, ChinaPhoto from Google
Earth
1 km
Mountain Pass, CA, Source: Molycorp
~1 km
Rare Earth Sources
• Active mines– China
• Baotou• Ionic Ores
• Mines coming on stream– USA
• Mountain Pass, CA
– Australia• Mt. Weld
• Under Development– Australia
• Nolan’s Bore
– Canada• Hoidas Lake• Nechalacho
– India– Brazil– USA– Vietnam– Russia
Early Lighting Options
WelsbachCandoluminescence
EdisonIncandescence
Source: Wikipedia
Source: Auer Licht
Source: Gas Light Guys
Lighting Phosphors
Lighting Phosphors
• What we see depends on the phosphors
• Red: Y2O3: Eu
• Green: (La, Ce, Tb) PO4
• Blue: BaMgAl10O17:Eu
Source: GE Lighting
Compact Fluorescent Lights (CFL)
Fluorescent Lighting
• Advantages– Higher output
• 58 lu/W vs. 13.5 lu/W
– Lower operating cost
• 10 W vs. 40 W
– Longer life • 12,000 hrs vs. 1,000
hrs
• Disadvantages– Slightly higher
price– Difficulty dimming– Unappealing light?
• Cheap bulb = cheap phosphors
– Hg in bulb, special disposalData source: GE
Lighting
Automotive Catalysts
Source: BASF The metal oxide is cerium
Refining Catalysts
• Fluid Cracking Catalyst (FCC)– A traditional use of lanthanum– Ideal for heavy crude to make gasoline– Ion-exchanged zeolite (cat litter)– Variable demand
• Driving season and heating season• Available crude oil
Current Magnet Applications
• Hard drive– Voice Coil Motor (VCM)– Spindle motors– 5 x 108 per year
Source: Western Digital
Current Magnet 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 Cranksha
ftPositionSensors
WindshieldWiperMotor
StarterMotor
CoolantFan
Motor
IgnitionSystems
HeadlightDoor
Motor
Economy and
PollutionControl
LiquidLevel
Indicators
Windshield
WasherPumpGauges
CDPlayer
HeadRest
MotorSunRoof
Motor
ElectricPower
Steering and Sensor
Lumbar Support
AutomaticTemperature
Control
DoorGasket
DefoggerMotor
Speakers
Source: Magnequench
New Rare Earth Magnet Applications
• Automotive– Hybrids– Electric vehicles
Source: Toyota
Emerging Magnet Applications
The basic components of a wind turbine.
Source: Department of Energy
Emerging Magnet Applications
• Wind Turbines– Reliability– The gearbox– About 500 kg of
magnet per MW– Small % use
magnets– 260 GW more in US
by 2030*
Source: Vestas AS
*Source: AWEA.org
Recycling
• Historically unimportant– Value– Difficulty
• Interest rises and falls with prices• Two areas of interest
– Eu, Tb and Y oxides from lighting phosphors
– Nd and Dy from magnets, mainly hard drives
Material Selection & Specification of Permanent Magnets
• Motivation• Basic Considerations• Advanced Considerations• Specification• Checklist
Motivation
• Gross oversimplification• Errors of omission• Lack of protocol
Basic Considerations
Advanced Considerations
• Physical• Mechanical• Corrosion• Magnetizing
• Assembly• Adhesives• Testing
Writing a Specification
• Two Approaches– What I happen to have
– What I actually need• Avoid Contradictions• IEC or IMA (MMPA) standards• Supplier Reference, or equivalent
Checklist
• Magnetic parameters• Flux variations• Dimensions/Tolerances• Testing• Magnetizing
• Coating• Adhesive• Assembly• Others
Case Study 1
• Direct substitution of bonded NdFeB for ferrite– Saturated return structure– Poor performance
• Increase the thickness of the return path, more poles
Case Study 2
• Bonded NdFeB ring for angle sensing application– Incorrect magnetization (axial) yields poor performance– Correct magnetization, with hairpin fixture, yields good
signal and contained flux
B = Br ln (do/di)
Case Study 3
Window Lift MotorToyota Prius and Toyota
Harrier
Source: Dr. B. GriebMagnequench
3D Model of Benchmark2 Pole PMDC (Brush Motor)Skewing on the armature teeth
Torque-Speed and Torque-Current Characteristics for the Benchmarked and
Redesigned Motors
Torque-Efficiency Characteristics for the Benchmarked and Redesigned Motors
Benchmarked Motor
Redesigned Motor
1 1 1 1 1 1
0.74 0.74
0.88
0.380.44
0.99
Diameter Length Width Weight Volume Cost
2-Pole Ferrite 4-Pole Bonded Neo
The Future• Niels Bohr, “Prediction is very difficult,
especially about the future.”• Supply and Demand are dynamic• Overreacting and underreacting are
normal– Supply– Demand– Government
• Finding equilibrium is difficult & takes time• Energy conservation is a major driver• We need to use these materials wisely
Permanent Magnets for Energy Applications Part 2• Rare Earths
– Basic facts– The crisis– Mines– Applications
• Magnet Recycling• Permanent Magnet Selection &
Specification• Case Studies• The Future