Fiberglass and Glass Technology (eBook)

Dr. Wallenberger completed his undergraduate studies in Chemistry at the University in Graz, Austria (1954) and pursued graduate research at Fordham University in New York, where he received his M.S. degree (1956) in pilot process research and his Ph.D. in Organic Chemistry (1958) in the chemistry of polycyclic aromatic carbon precursors. He was an Instructor in Chemistry at Fordham (1957-58) and a Research Fellow at Harvard (1958-59). He joined Du Pont Fibers, Pioneering Research Laboratory, in 1959, where he studied, for more than three decades, the relationships between structures, properties and value-in-use of new materials, and contributed to the commercialization of new fibers, polymers and composites through intrapreneurial research, project management and technology transfer. Dr. Wallenberger retired from DuPont in 1992, became a Research Professor (Materials Science) at the University of Illinois in Urbana-Champaign in 1992, a Visiting Professor (Textiles) at the University of California in Davis in 1994. He joined PPG in Pittsburgh as Staff Scientist in 1995. Dr. Wallenberger is a fiber scientist, an expert in the fields of advanced glass, ceramic and carbon fibers, single crystal fibers, whiskers and nanotubes, natural fibers, advanced polymers and fiber-reinforced composites. He is also a specialist in technology assessment and technology transfer. At the University of Illinois, he jointly taught successive project-based team courses with a member of the business faculty on the principles of organizing new high tech businesses. At the University of California he taught textile fibers and manufacture, and a University-wide course on the benefits of plastics to the society and their impact on the environment. Between 1992 and 1995, he was a consultant and assisted entrepreneurial start-up businesses with organizational advice, business strategy and license negotiations. Since 1957, Dr. Wallenberger has contributed 152 publications including journal articles, books, book chapters and patents to the scientific and technical literature. His publications appeared in selected technical journals, including Science, the Journal of Non-Crystalline Solids, the American Ceramic Society, Applied Physics, Materials Letters, Materials Processing and Manufacturing Science, Chemical Vapor Deposition, Angewandte Chemie, Organic Chemistry and Polymer Chemistry. More recently, his publications described the design of environmentally friendly fiberglass compositions (Journal of Non-Crystalline Solids, 2004, Ceramic Transactions, 2004, and Glastechnische Berichte - Glass Science and Technology, 2004), the structure of glass fibers (Science, 1995), rapid prototyping directly from the vapor phase (Science, 1994), pure carbon fibers from the vapor phase (Science, 1993) and melt spinning of amorphous alumina fibers (Journal of the American Ceramic Society, 1992). Ten of his original journal papers were reprinted by other journals since 1962, mostly in the form of a translation into another language. Dr. Wallenberger has published three books, "Natural Fibers, Polymers and Composites" (Kluwer, 2003), "Advanced Fibers, Plastics and Composites" (MRS, 2002) and "Advanced Inorganic Fibers" (Kluwer, 1999). He wrote a chapter on "Glass Fibers" (Handbook on Ceramics and Glasses, 2005), two chapters on "Reinforcing Fibers" (ASM Composites Handbook, 2001), a survey of "Melt-Spinning of Amorphous Alumna Fibers" (American Ceramic Society Bulletin, 1991) and the first review of "The Chemistry of Heat Resistant Polymer Fibers" (Angewandte Chemie, 1964). Among many professional honors, Dr. Wallenberger received the Environmental Respect Award from Du Pont. He is a Fellow of the American Ceramic Society, and a member of the American Chemical Society, the Material Research Society, and the Association of Harvard Chemists. Dr. Paul A. Bingham received a BEng (Hons) in 1995 from the Department of Engineering Materials at the University of Sheffield. Also at the Department of Engineering Materials, one of the world's premier glass research groups, he subsequently investigated the optical properties, the redox behavior, and the structure of iron-containing silicate glasses, and received his PhD in 1999. Between 1999 and 2003 he was a Technologist at Glass Technology Services Ltd (GTS), the research arm of the British Glass Manufacturers Confederation, and carried out a wide range of research and project management functions related to the development of new glasses.  He reformulated existing container glasses for environmental benefit and energy reduction, and giver glass compostions which he developed have achieved full-scale production.  In 2004, he took a position as Postdoctoral Research Associate at the Immobilization Science Laboratory (ISL), University of Sheffield, where he researches composition-structure-property relations for a large range of glass systems with the aim of providing environmental benefit.  He has developed novel silicate, borosilicate, phosphate and borophosphate glasses with potential applications in waste immobilization and commercial glassmaking. Dr. Bingham has nine publications in refereed journals including several papers in the field of glasses for environmental benefit and an invited review paper on the vitrification of toxic wastes.  He has also published several conference papers and other articles in the field.  Dr. Bingham is a member of the Society of Glass Technology, where he is Secretary of the Basic Science and Technology Committee.  He has also undertaken consultancy work for the optical communications industry.

Preface 5
About the Editors 7
Contents 9
Contributors 15
Part I Continuous Glass Fibers 16
1 Commercial and Experimental Glass Fibers 17
1.1 Overview: Glass Melt and Fiber Formation 17
1.1.1 Principles of Glass Melt Formation 17
1.1.1.1 Important Glass Melt Properties 18
1.1.1.2 Behavior of Strong Viscous Melts 22
1.1.1.3 Behavior of Fragile Viscous Melts 22
1.1.1.4 Behavior of Inviscid Glass Melts 23
1.1.2 Principles of Glass Fiber Formation 23
1.1.2.1 Generic Fiber-Forming Processes 23
1.1.2.2 Fibers from Strong Melts and Solutions 24
1.1.2.3 Fibers from Fragile and Inviscid Melts 25
1.1.3 Structure of Melts and Fibers 25
1.1.3.1 From Glass Melts to Fibers 25
1.1.3.2 Melt Structure vs. Liquidus 26
1.1.3.3 Fiber Structure vs. Modulus 26
1.1.3.4 Fiber Structure vs. Strength 28
1.1.4 Summary and Conclusions 29
1.2 Silica Fibers, Sliver, and Fabrics (95-100% SiO2) 29
1.2.1 Ultrapure Silica Fibers (99.99-99.999% SiO2) 29
1.2.1.1 Downdrawing from Strong Viscous Melts at the Preform Surface 29
1.2.1.2 Ultrapure Silica Fibers from Sol--Gels 32
1.2.2 Pure Silica Sliver and Fabrics (95.5099.50 SiO2) 33
1.2.2.1 Pure Silica Sliver from Aqueous Solution 33
1.2.2.2 Acid-Leached E- and A-Glass Fabrics (95.0095.50 SiO2) 35
1.2.3 Summary and Conclusions 36
1.3 Silicate Glass Fibers (50–70% SiO2, 1–25% Al2O3) 37
1.3.1 Forming Glass Fibers from Strong Viscous Melts 37
1.3.1.1 Critical Properties of Strong Viscous Melts 37
1.3.1.2 Commercial Manufacturing Process 37
1.3.1.3 Experimental Plasma Melt Process 40
1.3.1.4 Modeling of Glass Fiber Drawing 42
1.3.2 General-Purpose Silicate Glass Fibers 42
1.3.2.1 Borosilicate E-Glass Fibers 42
1.3.2.2 E-Glass Properties and Fiber Structures 45
1.3.2.3 Commercial E-Glass Products and Applications 47
1.3.3 Special-Purpose Silicate Glass Fibers 48
1.3.3.1 Designations of Special-Purpose Fibers 48
1.3.3.2 High-Strength--High-Temperature Glass Fibers 48
1.3.3.3 High-Modulus--High-Temperature Glass Fibers 53
1.3.3.4 Ultrahigh-Modulus Glass Ceramic Fibers 54
1.3.3.5 Glass Fibers with High Chemical Stability 58
1.3.3.6 Other Special-Purpose Glass Fibers 63
1.3.4 Non-round, Bicomponent and Hollow Silicate Fibers 68
1.3.4.1 Glass Fibers with Non-round Cross Sections 68
1.3.4.2 Bicomponent Silicate Glass Fibers 70
1.3.5 Summary and Conclusions 74
1.4 Aluminate Glass Fibers (=81% Al2O3, =50% SiO2) 74
1.4.1 Glass Fibers from Fragile Melts (25–50% Al2O3,10–4% SiO2) 74
1.4.1.1 Downdrawing from Supercooled Melts 74
1.4.1.2 Updrawing from Supercooled Melts 76
1.4.1.3 Quaternary Calcium Aluminate Fibers 78
1.4.1.4 Hybrid Fiber-Forming Processes 79
1.4.2 Glass Fibers from Inviscid Melts (55–81% Al2O3, 4–0% SiO2) 80
1.4.2.1 Principles of Fiber Formation from Inviscid Melts 80
1.4.2.2 Containerless, Laser Heating (CLH) Process 82
1.4.2.3 Inviscid Melt Spinning (IMS) Process 84
1.4.2.4 Rapid Jet Solidification (RJS) Processes 90
1.5 Appendix: Single-Crystal Alumina Fibers 91
1.5.1 Single-Crystal Fibers from Inviscid Melts 91
1.5.1.1 Edge-Defined Film-Fed Growth 92
1.5.1.2 Laser-Heated Float Zone Growth 92
1.5.2 The Future of Alumina and Aluminate Fibers 96
1.5.2.1 Amorphous Alumina vs. Single-Crystal Sapphire Fibers 96
1.5.2.2 Amorphous YAG vs. Single-Crystal YAG Fibers 97
1.5.2.3 Summary, Conclusions, and Outlook 97
References 98
2 Design of Energy-Friendly Glass Fibers 105
2.1 Principles of Designing New Compositions 105
2.1.1 Compositional, Energy, and Environmental Issues 105
2.1.1.1 Environmental Regulations and Emission Control 106
2.1.1.2 Industry Standards and Specifications 106
2.1.2 Trend Line Design of New Fiberglass Compositions 108
2.1.2.1 Glass Databases and Compositional Models 108
2.1.2.2 Principles of Trend Line Design 108
2.1.2.3 Design Required Melt Properties 109
2.1.2.4 Compositions, Energy Use, and Emissions 112
2.2 Energy-Friendly Aluminosilicate Glass Fibers 113
2.2.1 New Energy-Friendly E-Glass Variants with < 2% B2O3
2.2.1.1 Ternary SiO2-Al2O3-CaO Phase Diagram 114
2.2.1.2 Quaternary SiO2-Al2O3-CaO-MgO Phase Diagram 116
2.2.2 New Energy-Friendly E-Glass Variants with 2–10% B2O3 125
2.2.2.1 Quaternary SiO2-Al2O3-CaO-B2O3 Phase Diagram 125
2.2.2.2 Trend Line Design of Energy-Friendly Variants 125
2.2.2.3 Effect of B2O3 at the Same Delta Temperature 127
2.2.2.4 Summary and Conclusions 127
2.2.3 New Energy- and Environmentally Friendly ECR-Glass Variants 128
2.2.3.1 Commercial Corrosion-Resistant ECR-Glass 128
2.2.3.2 Fluorine- and B2O3-Free E-Glass with ZnO, TiO2, and/or Li2O 128
2.3 Energy-Friendly SodaLimeSilica Glass Fibers 130
2.3.1 New Energy-Friendly A- and C-Glass Compositions 131
2.3.1.1 Fluorine and Boron-Free A-Glass 131
2.3.1.2 Fluorine-Free C-Glass with 5% B2O3 131
2.3.1.3 Future Soda--Lime--Silica Glass Fibers and Glasses 133
2.4 Summary, Conclusions, and Path Forward 133
References 135
3 Composite Design and Engineering 138
3.1 Introduction 138
3.1.1 Continuous Fibers for Reinforcement 138
3.1.2 E-Glass Fibers 140
3.1.3 Fiberglass Manufacturing 141
3.1.4 Fiberglass Size 142
3.1.5 Composite Mechanical Properties 143
3.1.5.1 Unidirectional Continuous Fibers 144
3.1.5.2 Bidirectional (Orthotropic) Reinforcement 146
3.1.5.3 Random Short Fibers 147
3.1.5.4 Test Methods 150
3.1.6 Products 151
3.2 Thermoset Composite Material 154
3.2.1 Liquid Resin Processing Techniques 155
3.2.1.1 Hand Lay-Up (HLU) 156
3.2.1.2 Spray Deposition 156
3.2.1.3 Resin Transfer Molding (RTM) 156
3.2.1.4 Reinforced Reaction Injection Molding (RRIM) 157
3.2.1.5 Filament Winding 157
3.2.1.6 Centrifugal Molding 157
3.2.1.7 Pultrusion 158
3.2.1.8 Continuous Laminating 158
3.2.1.9 Pre-combined Materials 159
3.2.2 Thermosetting Matrix Resins 161
3.2.2.1 Unsaturated Polyester (UP) Resins 161
3.2.2.2 Epoxy (EP) Resins 163
3.2.2.3 Vinyl Ester (VE) Resins 164
3.2.2.4 Phenolic (PF) Resins 165
3.2.2.5 Polyurethanes (PUR) 166
3.2.2.6 Silicone (SI) Resins 166
3.2.3 Fillers 167
3.2.4 Release Agents 168
3.3 Reinforced Thermoplastic Materials 169
3.3.1 Introduction 169
3.3.2 Semifinished Materials Based on Thermoplastics 171
3.3.2.1 Reinforced Thermoplastic Compounds (RTP) 171
3.3.2.2 Glass Mat Thermoplastic (GMT) and Long Fiber Thermoplastic (LFT) 172
3.3.2.3 Mechanical Properties of Compounds 173
3.3.2.4 Semicrystalline Resins 177
3.3.2.5 Amorphous Resins 178
3.3.2.6 Heat-Resistant Polymers (HT) 179
3.3.2.7 Liquid Crystal Polymers (LCPs) 180
3.4 Composites for Wind Turbines 181
3.4.1 Introduction 181
3.4.2 Raw Materials 182
3.4.3 Blade-Manufacturing Techniques 182
3.4.4 Blade Design Methodologies 183
References 185
4 Glass Fibers for Printed Circuit Boards 187
4.1 Introduction 187
4.1.1 Printed Circuit Board Requirements and Their Implications for Fiberglass 188
4.1.2 Fiberglass' Role in PCB Construction 189
4.1.3 Electrical Aspects 191
4.1.3.1 Dielectric Constant 191
4.1.3.2 Dielectric Loss 192
4.1.3.3 Hollow Filaments 193
4.1.4 Structural Aspects 193
4.1.4.1 Mechanical Strength 194
4.1.4.2 Elastic Modulus 194
4.1.4.3 Thermal Expansion 194
4.1.4.4 Upper Use Temperature 195
4.1.4.5 Weave and Fabric Construction 196
4.2 Glass Compositional Families 196
4.2.1 Improvements Initially Based on E-Glass 196
4.2.1.1 E-Glass -- The Industry Standard 197
4.2.1.2 Improving Dielectric Properties of E-Glass 198
4.2.1.3 Challenges and Limitations 199
4.2.2 D-Glass and Its Compositional Improvements 200
4.2.2.1 D-Glass 200
4.2.2.2 Improvements Based on D-Glass 201
4.2.2.3 Challenges and Limitations 202
4.3 Future Needs of the PCB Market 203
4.3.1 The Electronics Manufacturer's Roadmap 203
4.3.2 What This Means for the Board and Yarn Makers 204
References 207
5 High-Strength Glass Fibers and Markets 209
5.1 Attributes of High-Strength Glass 209
5.1.1 Strength 210
5.1.2 Elastic Modulus 215
5.1.3 Thermal Stability 217
5.2 Glass Compositional Families 218
5.2.1 S-Glass 219
5.2.2 R-Glass 220
5.2.3 Other High-Strength Glasses 221
5.3 High-Strength Glass Fibers in Perspective 222
5.3.1 The Competitive Material Landscape 222
5.3.1.1 Carbon Fibers 224
5.3.1.2 Polymer Fibers 224
5.3.1.3 The Importance of Specific Properties 226
5.3.2 Inherent Advantages of Continuous Glass Fibers 227
5.4 Markets and Applications 227
5.4.1 Defense -- Hard Composite Armor 228
5.4.1.1 Application Overview 228
5.4.1.2 Critical Fitness for Use Properties 229
5.4.1.3 Market Trends and Future Needs 230
5.4.2 Aerospace -- Rotors and Interiors 230
5.4.2.1 Application Overview 230
5.4.2.2 Critical Fitness for Use Properties 230
5.4.2.3 Market Trends and Future Needs 231
5.4.3 Automotive -- Belts, Hoses, and Mufflers 232
5.4.3.1 Application Overview 232
5.4.3.2 Critical Fitness for Use Properties 232
5.4.3.3 Market Trends and Future Needs 233
5.4.4 Industrial Reinforcements -- Pressure Vessels 233
5.4.4.1 Selected Application Overview 233
5.4.4.2 Critical Fitness for Use Properties 234
5.4.4.3 Market Trends and Future Needs 234
5.5 Concluding Remarks 234
References 235
Part II SodaLimeSilica Glasses 238
6 Compositions of Industrial Glasses 239
6.1 Guidelines for Industrial Glass Composition Selection 239
6.1.1 Economics 240
6.1.2 Demands on the Glass Melt 240
6.1.3 Meltability 242
6.1.4 Workability 243
6.1.5 Choice of Raw Materials 245
6.1.6 Cullet Effect -- Glass Melt Production Heat 246
6.1.7 Glass Refining 247
6.2 Industrial Glass Compositions 250
6.2.1 Historical Development 250
6.2.2 Flat Glass 252
6.2.3 Container Glass 255
6.2.4 Lead-Free Utility Glass 260
6.2.5 Technical Glass 263
6.2.6 Lead Crystal 269
6.2.7 Colored Glasses 271
6.3 Example Glass Compositions 271
6.3.1 Perspectives 271
6.3.2 Practical Examples of Container Glass Batch Charge 272
References 276
7 Design of New Energy-Friendly Compositions 277
7.1 Introduction 277
7.2 Design Requirements 278
7.2.1 Commercial Glass Compositions 279
7.3 Environmental Issues 279
7.3.1 Specific Energy Consumption 279
7.3.1.1 Energy Efficiency 279
7.3.2 Atmospheric Emission Limits 281
7.3.3 Pollution Prevention and Control 281
7.3.3.1 Furnace Design 281
7.3.3.2 Carbon Dioxide 283
7.3.3.3 Oxides of Nitrogen 283
7.3.3.4 Oxides of Sulfur 285
7.3.3.5 Volatilization and Particulates 286
7.4 Fundamental Glass Properties 288
7.4.1 Viscosity--Temperature Relationship 289
7.4.1.1 Viscosity Models 291
7.4.2 Devitrification and Crystal Growth 291
7.4.2.1 Methods of Avoiding Devitrification 292
7.4.2.2 Liquidus Models 294
7.4.3 Conductivity and Heat Transfer 296
7.4.3.1 Specific Heat Capacity 296
7.4.3.2 Thermal Conductivity and Optical Properties 297
7.4.3.3 Electrical Properties 299
7.4.4 Interfaces, Surfaces, and Gases 301
7.4.4.1 Refining 301
7.4.4.2 Refractory Corrosion 303
7.4.4.3 Surface Energy 306
7.4.5 Chemical Durability 307
7.4.6 Density and Thermo-mechanical Properties 309
7.5 Design of New SLS Glasses 310
7.5.1 Batch Processing, Preheating, and Melting 310
7.5.2 Cullet 312
7.5.3 Silica, SiO2 314
7.5.3.1 SiO 2 Raw Materials 314
7.5.3.1 SiO2 Raw Materials 315
7.5.4 Soda, Na2O 315
7.5.4.1 Na2O Raw Materials 315
7.5.4.2 Na2O Effects on Glass Properties 317
7.5.5 Calcia, CaO 317
7.5.5.1 CaO Raw Materials 317
7.5.5.2 CaO Effects on Glass Properties 318
7.5.6 Magnesia, MgO 319
7.5.6.1 MgO Raw Materials 319
7.5.6.2 MgO Effects on Glass Properties 319
7.5.7 Alumina, Al2O3 320
7.5.7.1 Al2O3 Raw Materials 320
7.5.7.2 Al2O3 Effects on Glass Properties 321
7.5.8 Potassia, K2O 323
7.5.8.1 K2O Raw Materials 323
7.5.8.2 K2O Effects on Glass Properties 324
7.5.9 Lithia, Li2O 325
7.5.9.1 Li2O Raw Materials 325
7.5.9.2 Li2O Effects on Glass Properties 325
7.5.10 Boric Oxide, B2O3 326
7.5.10.1 B2O3 Raw Materials 326
7.5.10.2 B2O3 Effects on Glass Properties 327
7.5.11 Sulfate, SO3 328
7.5.12 Water, H2O 331
7.5.13 Chlorides and Fluorides 332
7.5.14 Baria, BaO 333
7.5.15 Zinc Oxide, ZnO 333
7.5.16 Strontia, SrO 334
7.5.17 Multivalent Constituents 334
7.5.17.1 Colorants and Refining Agents 334
7.5.17.2 Effects on Physical Properties 336
7.5.18 Other Compounds 337
7.5.19 Recycled Filter Dust 339
7.5.20 Nitrates 339
7.6 Glass Reformulation Methodologies 340
7.6.1 Worked Examples and Implementation 340
7.6.1.1 Reformulation Constrained by Composition 343
7.6.1.2 Reformulation Constrained by Batch 345
7.6.1.3 Unconstrained Reformulation 347
7.6.1.4 Other Industrial Trials and Implementation 349
7.6.2 Reformulation Benefits and Pitfalls 351
7.6.3 Research Requirements and Closing Remarks 353
References 355
Part III Glass Melting Technology 362
8 Basics of Melting and Glass Formation 363
8.1 Motivation 363
8.2 Former Melting Criteria 364
8.3 Analysis of the Enthalpy Functions of One-Component Systems 367
8.3.1 Theoretical Preliminaries 367
8.3.2 Pre-melting Range and the Contribution to the Molar Specific Heat Capacity by Electrons 369
8.4 Melting and the Glass Transformation 373
8.5 Effects Occurring in the Glass Transformation Range 376
8.6 What Makes Solids and Melts Expand? 377
8.7 Modulus of Compression of the Chemical Elements 383
8.8 Necessary Criteria for Glass Formation 383
8.9 Possible Extension to Multi-Component Systems 389
8.10 Discussion 389
References 390
9 Thermodynamics of Glass Melting 392
9.1 Approach to the Thermodynamics of Glasses and Glass Melts 392
9.1.1 Description Frame for the Thermodynamic Properties of Industrial Glass-Forming Systems 393
9.1.2 Heat Content of Glass Melts 395
9.1.3 Chemical Potentials and Vapor Pressures of Individual Oxides 398
9.1.4 Entropy and Viscosity 401
9.2 The Role of Individual Raw Materials 402
9.2.1 Sand 402
9.2.2 Boron Carriers 404
9.2.3 Dolomite and Limestone 407
9.3 The Batch-to-Melt Conversion 411
9.3.1 Stages of Batch Melting 411
9.3.2 Heat Demand of the Batch-to-Melt Conversion 412
9.3.3 Modeling of the Batch-to-Melt Conversion Reaction Path 414
References 416
10 Glass Melt Stability 420
10.1 Introduction 420
10.2 Target Properties of Glass Melt and Glass Product 421
10.2.1 Batch-Related Fluctuations 422
10.2.2 Combustion-Related Fluctuations 423
10.2.3 Process-Related Fluctuations 423
10.3 In Situ Sensors 424
10.3.1 Sensors for Monitoring Glass Melt Properties 425
10.3.1.1 Viscosity 425
10.3.1.2 Redox Measurement 425
10.3.1.3 Voltammetric Sensor 426
10.3.1.4 Emission Spectroscopy 428
10.3.1.5 Laser-Induced Breakdown Spectroscopy (LIBS) 429
10.3.2 Sensors for Monitoring Species in the Combustion Space 429
10.3.2.1 Sensors for Environmental Measurements 429
10.3.2.2 Sensors for Optimizing Combustion Efficiency 430
10.4 Examples of Glass Melt Stability Control 430
10.4.1 Redox Control of Glass Melting with High Portions of Recycled Glass 430
10.4.2 Redox Control of Amber Glass Melting 432
10.5 Conclusions and Outlook 434
References 434
11 Plasma Melting Technology and Applications 437
11.1 Concepts of Modular and Skull Melting 437
11.2 The Technology of High-Intensity DC-Arc Plasmas 439
11.2.1 Conductive 440
11.2.2 Radiant 441
11.2.3 Joule Heating 442
11.3 Brief History of Plasma Melting of Glass 443
11.3.1 Johns-Manville 443
11.3.2 British Glass Institute 444
11.3.3 Plasmelt Glass Technologies, LLC 444
11.3.4 Japanese Consortium Project 445
11.4 DOE Research Project 20032006 446
11.4.1 Acknowledgments 446
11.4.2 Experimental Setup of the Plasmelt Melting System 446
11.4.3 Technical Challenges of Plasma Glass Melting 448
11.4.4 Glasses Melted: Results and Broad Implications 450
11.4.4.1 Glass Melting Trials 450
11.4.5 Synthetic Minerals Processing Implications 453
11.4.6 Energy Efficiency vs. Throughput 454
11.4.6.1 Energy Efficiency 454
11.4.6.2 Energy Balance 455
11.5 Future Applications for Plasma Melting 456
11.6 Summary and Conclusions 457
References 457
Index 458