Rare Earth Metals and Minerals Industries: Status and Prospects

Preface
Contents
About the Editors
Chapter 1: Introduction
	1.1 What Are Rare Earth Elements?
	1.2 The Origin of Rare Earth Elements
	1.3 How Rare Earths Are Extracted
	1.4 How Rare Earth Elements are Separated and Refined
	1.5 How Rare Earth Elements Came to Light
	1.6 The Rare Earth Landscape
	1.7 Rare Earth Element Applications
	1.8 Magnets
	1.9 Catalysts
	1.10 Metallurgy and High-Temperature Coatings
	1.11 Rare Earth Element Recycling and End-of-Life Products
	1.12 Economics and Regulatory Issues
	1.13 Future Prospects
Part I: Upstream Primary Operations
	Chapter 2: Conventional Rare Earth Element Mineral Deposits—The Global Landscape
		2.1 Introduction
		2.2 Lanthanide Behavior in Natural Systems
			2.2.1 General Concepts
			2.2.2 Mineralogy
		2.3 Global Resources, Production, and Consumption
		2.4 Rare Earth Element Deposit Types and Their Geochemical Characteristics
			2.4.1 Rare Earth Mineral Systems
			2.4.2 Deposits Associated with Igneous Rocks—Magmatic REE Deposits
				Carbonatite
				Alkaline/Peralkaline Igneous
			2.4.3 Deposits Associated with Physical Weathering Environments
				Heavy Mineral Sands/Mineral Sands
			2.4.4 Deposits Associated with Chemical Weathering Environments
				Carbonatite Laterite Deposits
			2.4.5 Regolith-Hosted Ion-Adsorption Clay (IAC) REE Deposits
			2.4.6 Other Magmatic-Related Deposit Types
				Abyssal Pegmatite REE
				Apatite Intrusion REE/Apatite Vein Deposits
				Breccia Pipe REE
			2.4.7 Deposits Associated with Basin Hydrothermal and Basinal Chemoclines
				Phosphorite Deposits
			2.4.8 Unconformity-Related REE
		2.5 Outlook
		2.6 Summary
		References
	Chapter 3: Energy-Related Rare Earth Element Sources
		3.1 Introduction
		3.2 REE Distribution in Coal-Related Sources
		3.3 Coal Combustion Fly Ash
			3.3.1 REE Variation in Fly Ash
			3.3.2 Occurrence of REEs in Fly Ash
		3.4 Coal Resources
			3.4.1 REE-Enriched Coals, Coal Zones
				Terrigenous REE Enrichment
				Tuffaceous REE Enrichment
				Hydrothermal REE Enrichment
				Infiltrational REE Enrichment
				Within-Bed REE Variation
			3.4.2 Low-Rank Coals
		3.5 Coal Mining and Coal Preparation Wastes
			3.5.1 Pyrite in Coal, Waste Coal
			3.5.2 Other Elements of Interest
		3.6 Coal-Based Acid-Mine Drainage
			3.6.1 AMD Generation
			3.6.2 Advantages of REE Recovery from AMD
			3.6.3 Major Constituents of AMD
			3.6.4 Rare Earth Elements in AMD
				Dissolved Versus Particulate REEs
				MREE Enrichment
			3.6.5 AMD Treatment Approaches
				Active Treatment Approaches
				Passive Treatment Approaches
			3.6.6 REE in AMD Precipitates
		3.7 Economic Implications
			3.7.1 Critical Rare Earths Versus Critical Minerals
			3.7.2 Coal Ash
			3.7.3 Waste Coal
			3.7.4 Acid-Mine Drainage
			3.7.5 REE Recovery and CO2 Capture and Utilization
			3.7.6 Benefit from Remediation of Coal-Related Liabilities
			3.7.7 Role in a Circular Economy
		3.8 Summary
		References
	Chapter 4: Rare Earth Ore Flotation Principles and Kinetics: Significance of Collectors and Application of Novel Depressants
		4.1 Introduction
			4.1.1 Rare Earth Minerals
			4.1.2 Flotation
			4.1.3 Flowsheets
			4.1.4 Modeling
		4.2 Methods
		4.3 Results and Discussions
		4.4 Conclusions
		References
	Untitled
	Chapter 5: Rare Earth Extraction from Ion-Adsorption Clays in U.S. Coal By-Products
		5.1 Introduction
		5.2 Formation of Ion-Adsorption Clay Deposits
			5.2.1 Enrichment of REEs in Clay Minerals
			5.2.2 Fractionation of REEs
		5.3 Extraction Processes
			5.3.1 Ion-Exchange Leaching
			5.3.2 Colloid Phase
			5.3.3 Effect of Phosphate
			5.3.4 Environmental Issues
		5.4 Ion-Adsorption Clays in the United States
			5.4.1 Regolith-Hosted Deposit
			5.4.2 Coal By-Products
			5.4.3 Challenges
		5.5 Summary
		References
	Chapter 6: Solvent Extraction
		6.1 Introduction
		6.2 A Short History of the Rare Earth Element Separation Processes
		6.3 Solvent Extraction Chemistry of Metallic Species—Application to the Rare Earths
			6.3.1 Neutral or Solvating Extraction of Trivalent RE
			6.3.2 Basic or Ion Pair Extraction of Trivalent RE
			6.3.3 Acidic or Cationic Extraction of Trivalent RE
			6.3.4 The Specific Case of Tetravalent Cerium and Divalent Europium
			6.3.5 Chemical Formula of Some Important Ligands
		6.4 The RE Refining Process
			6.4.1 A Global View of the RE Separation Process by SX
				The Classical Configuration of a SX Circuit (SX Battery)
				The Multioutlet SX Battery Configuration
				The Hyperlink Configuration
			6.4.2 The Choice of the Solvent—An Economic and Environmental Decision
				The Selectivity of the Organic Ligand
				The Chemistry of the Organic Ligand
				The Loading Capacity of the Solvent
			6.4.3 Industrial Processes
				Chloride Route
				Nitrate Route
				Choosing Between Chloride and Nitrate Routes—An Economic and Environmental Decision
		6.5 The Simulation of Rare Earth Separations
			6.5.1 General Consideration
			6.5.2 Static Simulation
			6.5.3 Dynamic Simulation
		6.6 Solvent Extraction Equipment
			6.6.1 Mixer-Settlers
			6.6.2 Can Columns Be Used for RE Separation?
		6.7 Solid Phase Extraction—The New Holy Grail?
		6.8 Conclusions
		References
	Chapter 7: Continuous Ion Chromatography
		7.1 Introduction
		7.2 Continuous Ion Exchange (CIX)/Continuous Countercurrent Ion Exchange (CCIX)
			7.2.1 Valve Details
		7.3 Ion Exchange and Ion Chromatography
		7.4 Chromatographic Techniques
		7.5 Ion Exchangers and Adsorbents
		7.6 Complexing Agents
		7.7 CIX/CIC Industrial Applications
		7.8 Conclusion
		References
	Chapter 8: Ionic Liquids for the Processing of Rare Earth Elements
		8.1 Introduction
		8.2 Nomenclature and Molecular Structure of Selected Ionic Liquids Cations and Anions
		8.3 Solvent Extraction
			8.3.1 Use of Ionic Liquids as Extractants
			8.3.2 Use of Ionic Liquids as Solvents
			8.3.3 Aqueous Two-Phase System
		8.4 Mineral Processing
		8.5 Electrometallurgy
			8.5.1 Imidazolium-Based ILs
			8.5.2 Pyrrolidinium-Based ILs
			8.5.3 Phosphonium-Based ILs
			8.5.4 Neutral Ligand Complexation-Based ILs
			8.5.5 Aluminum Chloride-Based ILs
		8.6 Technology Outlook
		References
Part II: Metal Refining
	Chapter 9: Reduction of Rare Earth Elements Through Electrochemical and Metallothermic Methods
		9.1 Introduction and Thermodynamics Considerations
		9.2 Metallothermic Reduction
			9.2.1 Rare Earth Chlorides
				Preparation of Rare Earth Chlorides
				Metallothermic Reduction of Rare Earth Chlorides
			9.2.2 Rare Earth Fluorides
				Preparation of Rare Earth Fluorides
				Metallothermic Reduction of Rare Earth Fluorides
		9.3 Lanthanothermy
		9.4 Molten Salt Electrolysis
			9.4.1 Industrial Production of Rare Earth Metals by Electrolysis
			9.4.2 Industrial Production of Cerium and Mischmetal
		9.5 Electrowinning of Nd, Nd-Pr, and Dy-Fe
			9.5.1 Commercial Production of Nd, Nd-Pr, and Dy-Fe
			9.5.2 Alternative Rare Earth Electrodeposition
				Neochem Process
				The FFC Process
				Inorganic Liquids
		9.6 Environmental Concerns
		9.7 Conclusions
		References
	Chapter 10: Rare Earth Element Reduction to Metals
		10.1 Introduction
		10.2 Industrial REE Reduction Processes
			10.2.1 Metallothermic and Carbothermic Reduction
			10.2.2 Molten Salt Electrolysis
		10.3 Novel REE Reduction Processes
			10.3.1 FFC Cambridge Process
			10.3.2 Fueled Anode Molten Salt Electrolysis
			10.3.3 Carboxylate Reduction
			10.3.4 Ionic Liquid Electrodeposition
		10.4 Technology Outlook
		References
Part III: Applications – Product Manufacturing
	Chapter 11: Rare Earth Markets and Their Industrial Applications
		11.1 Introduction
		11.2 1790s–1900s: Discovery of Rare Earth Elements (REEs) and First Industrial Applications: Gas Mantle and Mischmetal
		11.3 1930s–1960s: Diversification of Uses and the Development of REE-Based Phosphors in Color Televisions
		11.4 1970s–1980s: The Rise of REE-Based Permanent Magnets
		11.5 1990s–2020s: Entering the “Chinese Era” and Associated Challenges
		11.6 Future Trends for the REE Market
		11.7 Conclusion
		References
	Chapter 12: Rare Earth Magnets: Manufacturing and Applications
		12.1 Introduction
		12.2 Basic Magnet Compositions
			12.2.1 Samarium Cobalt Magnets
			12.2.2 Neodymium Iron Boron Magnets
				Sintered NdFeB Magnets
				Bonded NdFeB Magnets
				Anosotropic Bonded NdFeB Magnets
				Hot Formed NdFeB Magnets
			12.2.3 Other Magnet Types and Processes
			12.2.4 Current Development Focus
		12.3 Major Applications
			12.3.1 The Automotive Industry
			12.3.2 The Electronics Industry: Computers
			12.3.3 The Medical Industry
			12.3.4 Industrial Products
			12.3.5 Consumer Products
			12.3.6 Green Energy
			12.3.7 Electric Vehicle Traction Motors
			12.3.8 Wind Generators
			12.3.9 The Defense and Aerospace Industry
		12.4 Intellectual Property
		12.5 U.S. Magnet Manufacture
		12.6 Major Players in the RE Magnet Supply Chain
		12.7 Conclusions and Final Outlook
		References
	Chapter 13: Role of Rare Earths as Catalysts in the Chemical, Petroleum and Transportation Industries
		13.1 Introduction
		13.2 Application of Rare Earths in Fluid Catalytic Cracking Catalysts
			13.2.1 Use of Rare Earths to Passivate Metal Contaminants
			13.2.2 Use of Rare Earths to Improve Catalyst Stability
			13.2.3 Effect of Rare Earths on the Activity of Catalysts
		13.3 Application of Rare Earths in the Transportation Industry
			13.3.1 Use of Rare Earths in Car Components
			13.3.2 Role of Rare Earths in Catalytic Converters
		13.4 Role of Rare Earths in Environmental Protection
			13.4.1 Rare Earths in Catalytic Combustion
			13.4.2 Use of Rare Earths in Air Pollution Control
		13.5 Application of Rare Earths in the Chemical Industry
			13.5.1 Use of Rare Earths in Methanol Synthesis
			13.5.2 Applications of Rare Earths in Coordination Chemistry
		13.6 Summary and Outlook
		References
	Chapter 14: High-Performance Aluminum Castings Containing Rare Earth Elements
		14.1 Introduction
		14.2 Background and History
		14.3 Metallurgical Aspects of the Al-Ce System
		14.4 Alloying Element Interactions
		14.5 Composite Potential in Al-Ce Alloys
		14.6 Product Forms
			14.6.1 Castings
			14.6.2 Extrusions
			14.6.3 Additive Manufacturing
			14.6.4 Consolidated Powders
		14.7 Economics of Al-Ce Alloys
		14.8 Conclusions
		References
	Chapter 15: Scandium in Commercial Wrought Aluminum Alloys
		15.1 Introduction
		15.2 The “Four Pillars” of Scandium in Aluminum
			15.2.1 Grain Refinement
			15.2.2 Increased Recrystallization Temperature
			15.2.3 Dispersoid Strengthening
			15.2.4 Nucleation of Other Strengthening Phases
				Al-Cu-Based 2xxx-Series Alloys
				Al-Mg-Si 6xxx-Series Alloys
		15.3 Development and Applications of Sc-Containing Wrought Alloys
			15.3.1 Al-Mg-Li (14XX-Series) Alloys
			15.3.2 Al-Mg (Mn) (5xxx/15xx-Series) Alloys
			15.3.3 Al-Zn-Mg (Cu) (7XXX/19XX-Series) Alloys
			15.3.4 Al-Mg-Si (Cu) (6XXX/13XX-Series) Alloys
			15.3.5 Other Alloy Systems
		15.4 Scandium Supply
			15.4.1 Mining Sc-Containing Minerals
			15.4.2 Extraction of Scandium as a Coproduct
				Rare Earth Mining
				Iron/Uranium Mining
				Nickel Laterite Mining
			15.4.3 Extraction of Scandium from Mining and Industrial Waste Streams
				TiO2 Production Waste Stream
				Red Mud – Waste Stream from Processing Bauxite into Alumina
				Extraction of Scandium from Coal Fly Ash
				Phosphogypsum Waste – Residual from Phosphorus Fertilizer
		15.5 Production of Scandium Master Alloys
		15.6 Conclusions
		References
	Chapter 16: Rare Earth Oxide Applications in Ceramic Coatings for Turbine Engines
		16.1 Protective Ceramic Coating Applications and Requirements
			16.1.1 Thermal Barrier Coatings (TBC) for Ni-Based Alloys
			16.1.2 Environmental Barrier Coatings (EBC) for Ceramics and Ceramic Composites
		16.2 Coating Material Families and Properties
			16.2.1 Rare Earth Oxide Chemistry
			16.2.2 Zirconia and Hafnia-Based Coating Materials
				Rare Earth-Stabilized Tetragonal Phases
				Rare Earth Zirconates and Hafnates
			16.2.3 Rare Earth Silicate Coating Materials
			16.2.4 Rare Earth Aluminate Coating Materials
			16.2.5 Other Material Families
				Rare Earth Phosphates
				Rare Earth Tantalates
		16.3 Coating Architecture Design Trends and Rare Earth Oxide Utilization
			16.3.1 Thermal Barrier Coatings
				Single Layer Top Coat Architectures
				Bilayer Top Coat Architectures
				Multilayer and Multiphase Top Coat Architectures
			16.3.2 Environmental Barrier Coatings for Ceramic Composites
				Rare Earth Silicate Architectures for SiC and Si3N4-Based Ceramics
				Coatings for Al2O3-Based Ceramics
				Multilayer Thermal-Environmental Architectures
		16.4 Rare Earth Containing Coating Feedstocks, Opportunities for Efficient Material Designs and Utilization and Outlook
		References
Part IV: Recycling
	Chapter 17: Value Recovery Pathways for Rare Earth Elements and Nd-Fe-B Magnets from End-of-Life Products
		17.1 Introduction
		17.2 Value Recovery Pathways
			17.2.1 Direct Reuse of EOL Products
			17.2.2 Dismantling EOL Products for Magnets and Magnet Assemblies
			17.2.3 Nd-Fe-B Magnet and Magnet Assembly Reuse
			17.2.4 Nd-Fe-B Magnet Remanufacturing
				Full-Density Magnet Remanufacturing
				Bonded Magnet Remanufacturing
			17.2.5 REE Recycling
			17.2.6 Economic and Environmental Implications of Value Recovery Pathways
		17.3 Future Outlook and Recommendations
		References
	Chapter 18: Recovery of Rare Earth Metals from Waste Fluorescent Lights
		18.1 Background
		18.2 Europium Recovery from Waste Fluorescent Phosphor Dust
			18.2.1 Eu(III) Reduction Chemistry
		18.3 Conclusions
		References
Part V: Economics and Regulatory Issues
	Chapter 19: Fundamental Perspectives on the Economic Analysis of Rare Earth Processing from Various Feedstocks
		19.1 Introduction and Objectives
			19.1.1 Background
			19.1.2 Objectives and Organization
		19.2 Definitions and Valuation Methodologies
			19.2.1 Value Indicators
				REE Prices
				Basket Price
				Contained Value
			19.2.2 Cost Indicators
				Estimation Accuracy and Standards
				Capital Cost Estimation
				Operating Cost Estimation
			19.2.3 Economic Modeling and Worth Indicators
		19.3 Assessment of Conventional Resources
			19.3.1 Methodology and Limitations
			19.3.2 Metadata
			19.3.3 Project Resource Data
			19.3.4 Project Economic Data
			19.3.5 Analysis and Assessment
		19.4 Unconventional Resources
			19.4.1 Monazite Sand
			19.4.2 Coal and Coal Ash
			19.4.3 Acid Mine Drainage
			19.4.4 Seafloor Sediments
			19.4.5 Summary
		19.5 Summary and Conclusions
		References
	Chapter 20: Rare Earth Element Mining and Recovery: A Regulatory Overview
		20.1 Introduction: Current Regulatory Environment
		20.2 China
		20.3 European Union Regulatory Overview
		20.4 Australia
		20.5 United Nations Charter
		20.6 U.S. Regulatory Overview
			20.6.1 Presidential Executive Order
			20.6.2 The Administrative Procedure Act
			20.6.3 National Environmental Policy Act
			20.6.4 Clean Water Act
				CWA Section 303 Water Quality Standards
				CWA Section 401 Water Quality Certification
				CWA Section 402 Permits
				CWA Section 404 Wetlands
			20.6.5 Clean Air Act
			20.6.6 Resource Conservation Recovery Act
				Brownfields
			20.6.7 CERCLA/Superfund
				Emergency Planning and Community Right-To-Know Hazardous Chemical Inventory Reporting Requirements Section 311, 312, 313
			20.6.8 Atomic Energy Act
		20.7 Other Federal Environmental Regulations
			20.7.1 National Marine Sanctuaries Act
			20.7.2 Marine Mammal Protection Act
			20.7.3 Farmland Protection Act
			20.7.4 Migratory Bird Treaty Act
			20.7.5 Endangered Species Act
			20.7.6 Surface Mining Control and Reclamation Act of 1977
			20.7.7 The Marine Protection Research and Sanctuaries Act
		20.8 State Regulatory Environmental Overview
		20.9 Potential Regulatory Roadblocks
		20.10 Conclusions
		References
Index