1. Life Cycle Assessment of Rare Earth
Metal Production from Monazite
CPSE – MANUFACTURING MATERIALS & MINERALS – CLAYTON
Callum Browning | Vacation Student – Nawshad Haque | Supervisor
30 January 2014
2. Contents of Presentation
•Chemical Properties
•Industrial Uses
•Classification
Rare Earth Metal
Description
•Chemical structure
•Physical Characteristics
•Deposit Characteristics
Monazite
Description
•Stages of processing
•Flow sheet development
Processing Path
Description
•Ore Beneficiation
•Monazite Digestion
•Rare Earth Separation
Processing Path
Flow sheets
•GaBi Introduction
•Accounting for allocations
•Assumptions
GaBi Model
Development
•Gross Energy Demand
•Gross Mass Inputs
•Climate Change Impact
GaBi Model
Results
LCA of Rare Earth Production from Monazite | Callum Browning2 |
3. Rare Earth Metal Description
• Lanthanides, Scandium and
Yttrium
• 16 Naturally Occurring
• Scandium typically excluded
• Used predominantly in:
• Electronics
• Magnets
• Chemistry
• Ceramics
• Alloys
• Substitution Elements
• Chemically similar
• Trivalent state in deposits (RE3+)
• Separation is energy & material
intensive
LCA of Rare Earth Production from Monazite | Callum Browning3 |
Rare Earth Symbol Atomic Number
LightRareEarthElements
Lanthanum La 57
Cerium Ce 58
Praseodymium Pr 59
Neodymium Nd 60
Samarium Sm 62
Europium Eu 63
Gadolinium Gd 64
HeavyRareEarthElements
Terbium Tb 65
Dysprosium Dy 66
Holmium Ho 67
Erbium Er 68
Thulium Tm 69
Ytterbium Yb 70
Lutetium Lu 71
Yttrium Y 39
4. Monazite Properties
LCA of Rare Earth Production from Monazite | Callum Browning4 |
Chemical Properties
•Chemical Structure: (RE, U, Th)PO4
•Variable Rare Earth content
•40 – 60% Rare Earths
•6 – 10% Thorium
•0.5 – 1% Uranium
•Phosphates are recovered
Rare Earth Content
•Individual Rare Earth content varies
•20% La
•45% Ce
•5% Pr
•20% Nd
•5% Sm, Eu & Gd
•<5% HREE
Physical Properties
•Naturally Concentrated in deposits
•High Density
•High weathering resistance
•‘Placer’ Deposits
•River = Alluvial
•Ocean = Beach
Deposit Properties
•Co-occurring Heavy Minerals in placer
deposits:
•Quartz
•Magnetite
•Zircon
•Rutile
•Ilmenite
5. Processing Path Overview
• General Monazite processing
route
• ‘Cradle-to-Gate” Life Cycle
Assessment
• In: Raw resources
• Out: Rare Earth Metals
• No “Use phase” in LCA
• Difficulties
• Lack of Industry specific published
data
• Deposit specific processing paths
• Much literature very old!
LCA of Rare Earth Production from Monazite | Callum Browning5 |
Ore Beneficiation
Monazite
Monazite Digestion
Rare Earth
Concentrate
Rare Earth Separation
Rare Earth
Metals
6. Ore Beneficiation
LCA of Rare Earth Production from Monazite | Callum Browning6 |
Mining/Excavation Wet Gravity Separation
Oversize Screening Topsoil Monazite Stream Zircon Stream
Desliming Oversize Tailings Drying Magnetic Separation
Wet Gravity
Concetration Slimes Magnetic Separation Wet Gravity Separation Zircon
Drying Tailings High Tension Separation Zircon Drying
Magnetic Separation Monazite Tailings High Tension Separation
Wet Gravity
Concentration Ilmenite Magnetic Separation Tailings
Valuable RE Stream
Drying Tailings Waste Stream Monazite Tailings
Allocated Output
High Tension Separation
Processing Step
Rutile
7. Monazite Digestion
LCA of Rare Earth Production from Monazite | Callum Browning7 |
Monazite Hydrochloric Acid Digestion
Grinding & Classification Washing
Digestion in NaOH Solvent Extraction Unreacted Monazite
Water Leaching Rare Earth Chlorides Thorium Sulphate Sodium Uranyl Carbonate
Filtering Trisodium phosphate Valuable RE Stream
Waste Stream
Washing Unreacted Monazite
Allocated Output
Hydrochloric Acid Digestion Processing Step
Deactivation & Pb
Elimination U & Th Hydroxides
Rare Earth Chlorides Radium and Lead
9. GaBi Introduction
Rare Earth Production
Process
LCA of Rare Earth Production from Monazite | Callum Browning9 |
Resources from
Natural Environment
Rare Earth Metals
Wastes
• Database containing quantities for thousands of materials and
compounds including:
• Ecotoxicity (kg 1,4 DB eq.)
• Activity (Bq)
• Climate Change Contribution (kg CO2 eq.)
10. GaBi Model Development
• Flow sheets were generated in excel
• Mass/energy balance calculations
• Rare Earth recoveries of unit processes
• Relative mass/volumes of process streams
• Excel spreadsheets converted to GaBi model
• Allocation adjustment based on mass fraction
• All ‘upstream’ inputs & impacts divided between output products
LCA of Rare Earth Production from Monazite | Callum Browning10 |
11. GaBi Model Results
LCA of Rare Earth Production from Monazite | Callum Browning11 |
Gross Energy Use
0
5000
10000
15000
20000
25000
30000
35000
40000
GrossEnergyInput(kJ/kgMonazite)
12. GaBi Model Results
Gross Material Inputs
LCA of Rare Earth Production from Monazite | Callum Browning12 |
0
2
4
6
8
10
12
14
16
18
20
GrossMaterialInput(kg/kgMonazite)
Renewable Resources
Non-renewable Resources
Non-renewable Energy
13. GaBi Model Results
Climate Change
LCA of Rare Earth Production from Monazite | Callum Browning13 |
0.00
0.50
1.00
1.50
2.00
2.50
3.00
kgCO2e/kgMonazite
14. GaBi Model Results
Waste Production
LCA of Rare Earth Production from Monazite | Callum Browning14 |
0.00
200.00
400.00
600.00
800.00
1000.00
1200.00
1400.00
kgWaste/kgMonazite
Emissions to Sea Water
Emissions to Fresh Water
Emissions to Air
Deposited Goods
