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Permanent Magnets for Energy Applications Part 2. Stan 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.
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Permanent Magnetsfor Energy ApplicationsPart 2 Stan 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 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!
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
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 Recovery Goal: sell into marketplace Scale: 1010 gram Digestion: appropriate for scale and market Separation: appropriate for market conditions • Goal: understand composition • Scale: 10 gram • Digestion: complete as possible • Separation: no
Balance • The attempt by each rare earth processor to balance the available ore with the needs of the marketplace. Source: Kingsnorth
1 km Bayan Obo mine , near Baotou, China Photo from Google Earth
~1 km Mountain Pass, CA, Source: Molycorp
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 Welsbach Candoluminescence Edison Incandescence Source: Gas Light Guys Source: Wikipedia Source: Auer Licht
Lighting Phosphors • What we see depends on the phosphors • Red: Y2O3: Eu • Green: (La, Ce, Tb) PO4 • Blue: BaMgAl10O17:Eu Compact Fluorescent Lights (CFL) Source: GE Lighting
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 disposal Data 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
AutomaticTemperatureControl HeadRestMotor Speakers CDPlayer WindshieldWasherPump Lumbar Support SunRoofMotor DefoggerMotor Mirror Motors Cruise Control Tailgate Motor Gauges DoorGasket LiquidLevelIndicators ElectricPowerSteering and Sensor Door LockMotor Four Wheel Steering Anti-skidSensor and Motor Economy and PollutionControl WindowLiftMotor IgnitionSystems HeadlightDoorMotor SuspensionSystem StarterMotor CoolantFanMotor WindshieldWiperMotor FuelPumpMotor Seat BeltMotor Heater-A/C Blower Seat AdjustMotors Throttle and CrankshaftPositionSensors TractionControl AntennaLiftMotor Current Magnet Applications Source: Magnequench
New Rare Earth Magnet Applications • Automotive • Hybrids • Electric vehicles Source: Toyota
Emerging Magnet Applications Source: Vestas AS • Wind Turbines • Reliability • The gearbox • About 500 kg of magnet per MW • Small % use magnets • 260 GW more in US by 2030* *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
Physical Mechanical Corrosion Magnetizing Assembly Adhesives Testing Advanced Considerations
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
Magnetic parameters Flux variations Dimensions/Tolerances Testing Magnetizing Coating Adhesive Assembly Others Checklist
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 B = Br ln (do/di) • Bonded NdFeB ring for angle sensing application • Incorrect magnetization (axial) yields poor performance • Correct magnetization, with hairpin fixture, yields good signal and contained flux
Case Study 3 Window Lift Motor Toyota Prius and Toyota Harrier Source: Dr. B. Grieb Magnequench
3D Model of Benchmark 2 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
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