Essential Readings in Light Metals: Electrode Technology for Aluminum Production

ONE OF A FOUR-BOOK COLLECTION SPOTLIGHTING CLASSIC ARTICLES The best original research findings and reviews in the field of electrode technology Highlighting some of the most important findings and insights reported over the past five decades, this volume features original research papers and reviews on electrode technology for aluminum production published from 1963 to 2011. The papers have been divided into three subject sections: Part 1, Hall-Héroult Cell Carbon Anodes, includes anode raw materials, anode production, and anode performance. Part 2, Hall-Héroult Cell Cathodes, includes reduction cell materials and reduction cell failure mechanisms. Part 3, Inert Anodes and Wettable Cathodes, includes materials and performance. Each section has a brief introduction and a list of recommended articles for researchers interested in exploring each subject in greater depth. Papers for this volume were selected from among more than 1,100 articles published between 1963 and 2011 in Light Metals. Selection was based on a rigorous review process. Among the papers, readers will find landmark original research findings and expert reviews summarizing current thinking on key topics at the time of publication. From basic research to advanced applications, the articles published in this volume collectively represent a complete overview of electrode technology. It will enable students, scientists, and engineers new to the field to gain a quick introduction to the state of the technology. Moreover, it will enable more experienced practitioners to advance their own research and take full advantage of the latest technology and applications.

Preface xv Lead Editors xix Editorial Team xxi Part 1: Hall–Héroult Cell Carbon Anodes Section Introduction 1 Raw Materials: Coke Calcined Coke from Crude Oil to Customer Silo . 3 B. Vitchus, F. Cannova, and H. Childs Refinery Feedstocks, Coke Structures and Aluminum Cell Anodes......11 P. Rhedey and D. DuTremblay Coker Feedstock Characteristics and Calcined Coke Properties ....19 P. Rhedey and S. Nadkarni Quality and Process Performance of Rotary Kilns and Shaft Calciners 24 L. Edwards High Vanadium Venezuelan Petroleum Coke, A Rawmaterial for the Aluminum Industry?...30 U. Mannweiler, W. Schmidt–Hatting, D. Rodriguez, and A. Maitland Use of Shot Coke as an Anode Raw Material....36 L. Edwards, F. Vogt, M. Robinette, R. Love, A. Ross, M. McClung, R. Roush, and W. Morgan Influence of High Sulphur Cokes on Anode Performance42 S. Jones, R. Hildebrandt, and M. Hedlund Carbon Raw Material Effects on Aluminum Reduction Cell Anodes ...53 P. Rhedey and S. Nadkarni A Comprehensive Determination of Effects of Calcined Petroleum Coke Properties on Aluminum Reduction Cell Anode Properties ... 59 D. Belitskus and D. Danka A Comprehensive Review of the Effects of Calcination at Various Temperatures on Coke Structure and Properties — Part 2....73 E. Hardin, C. Beilharz, P. Ellis, and L. McCoy Influence of Coke Real Density on Anode Reactivity Consequence on Anode Baking....84 B. Coste and J. Schneider Coke Calcination Levels and Aluminum Anode Quality .93 C. Dreyer, B. Samanos, and F. Vogt Impact of Coke Calcination Level and Anode Baking Temperature on Anode Properties ....101 B. Samanos and C. Dreyer Use of Under–Calcined Coke for the Production of Low Reactivity Anodes ....109 J. Lhuissier, L. Bezamanifary, M. Gendre, and M. Chollier Anode Filler Coke Porosity Studies...114 P. Rhedey Desulphurization and Its Effect on Calcined Coke Properties...... 119 R. Garbarino and R. Tonti Influence of Petroleum Coke Sulphur Content on the Sodium Sensitivity of Carbon Anodes......123 S. Hume, W. Fischer, R. Perruchoud, J. Metson, and R. Baker A Review of Coke and Anode Desulfurization 130 L. Edwards, K. Neyrey, and L. Lossius Coke and Anode Desulfurization Studies .136 L. Lossius, K. Neyrey, and L. Edwards Minimizing Impact of Low Sulfur Coke on Anode Quality ..142 A. Adams, R. Cahill, Y. Belzile, K. Cantin, and M. Gendron Evaluating Calcined Coke for Aluminum Smelting by Bulk Density .148 D. Belitskus Maintaining Consistent Anode Density Using Varying Carbon Raw Materials156 S. Wilkening Coke Blending and Fines Circuit Targeting at the Alcoa Deschambault Smelter ....163 M. Gendron, S. Whelan, and K. Cantin Raw Materials: Pitch Worldwide Pitch Quality for Prebaked Anodes167 R. Perruchoud, M. Meier, and W. Fischer Coal Tar Pitch — Past, Present, and Future177 J. Baron, S. McKinney, and R. Wombles Electrode Binder Pyrolysis and Bond–Coke Microstructure..182 S. Jones and R. Hildebrandt Binder for the Ideal Anode Carbon....198 S. Jones and E. Bart Binding Characteristics of Coal Tar Pitches for Prebaked Anode Mix – Choice Criteria: LRF Report 830 215 J. Pinoir and P. Hyvernat The Influence of Solid Particles in Pitch on the Preparation and Baking of the Carbon Blocks ...225 G. Romovacek Performance of Binder Pitches With Decreased QI–Content in Anode Making: Formation – Nature – Properties and Substitution of Quinoline Insolubles .232 A. Alscher, R. Wildförster, and J. Sharp Temperature Stability of Søderberg Anode Pitch ....239 M. Sørlie Developing Coal Tar/Petroleum Pitches...246 R. Wombles and M. Kiser Raw Materials: Spent Carbon Investigation of the Quality of Recycled Anode Butts ...251 W. Schmidt–Hatting, A. Kooijman, and R. Perruchoud Interdependence Between Properties of Anode Butts and Quality of Prebaked Anodes.267 W. Fischer and R. Perruchoud Raw Material and Anode Characterization New Methods for Testing Raw Materials for Anode Carbon Paste.....271 O. Bowitz, T. Eftestol, and R. Selvik Standardization of a Calcined Coke Bulk Density Test..281 D. Belitskus Reactivity Testing of Anode Carbon Materials 290 G. Houston and H. Øye Characterization of Prebaked Anode Carbon by Mechanical and Thermal Properties....298 J. Brown and P. Rhedey Green Anode Production Aggregate Optimization Using a Y–Blender....307 R. Peterson Soderberg Paste. Effect of Fine Fraction Variations313 P. Stokka and I. Skogland Finer Fines in Anode Formulation.....318 F. Figueiredo, C. Cato, A. Nascimento, A. Marques, and P. Miotto Process Adaptations for Finer Dust Formulations: Mixing and Forming...322 K. Hulse, R. Perruchoud, W. Fischer, and B. Welch Effects of Mixing Variables and Mold Temperature on Prebaked Anode Quality...328 D. Belitskus Improving Anode Quality by Separately Optimising Mixing and Compacting Temperature 333 B. Coste Vibration Forming of Carbon Blocks 339 E. Sandvik, R. Blindheim, and H. Bø Cooling of Green Anodes After Forming .351 W. Fischer, M. Meier, and M. Lustenberger Recent Improvement in Paste Plant Design: Industrial Application and Results .....358 C. Vanvoren Going Beyond SPC — Why We Need Statistical Thinking in Operations Such as Carbon Plants .365 K. Sinclair and B. Sadler Properties and Behaviour of Green Anodes.....371 S. Wilkening Potentialities in the Paste Plant...378 S. Wilkening Baked Anode Production Mathematical Simulation of a Horizontal Flue Ring Furnace ...... 386 R. Bui, E. Dernedde, A. Charette, and T. Bourgeois Flue Gas Management ..390 W. Leisenberg Safe Operation of Anode Baking Furnaces......396 I. Holden, O. Saeter, F. Aune, and T. Naterstad Anode Baking: The Underestimated Human Aspect ......403 F. Keller, P. Sulger, and W. Fischer Specific Energy Consumption in Anode Bake Furnaces 408 F. Keller, P. Sulger, M. Meier, D. Severo, and V. Gusberti Evaluation of the Uniformity of Baking in Horizontal and Vertical Flue Ring Furnaces414 D. Holdner, S. Nadkarni, and D. DuTremblay Measurement and Control of the Calcining Level in Anode Baking Furnaces..418 T. Foosnaes, N. Kulset, H. Linga, G. Naeumann, and A. Werge–Olsen The Equivalent Temperature Method for Measuring the Baking Level of Anodes.. 422 L. Lossius, I. Holden, and H. Linga Baking Parameters and the Resulting Anode Quality.....427 W. Fischer, F. Keller, R. Perruchoud, and S. Oderbolz Anode Desulphurization on Baking...434 M. Vogt, K. Ries, and M. Smith The Effect of Prebake Anode Baking Temperature on Potroom Performance ..444 G. Bain, J. Pruneau, and J. Williams Influence of Baking Temperature and Anode Effects Upon Carbon Sloughing450 E. Cutshall and V. Bullough Influence on Anode Baking Temperature and Current Density Upon Carbon Sloughing......469 E. Cutshall Anode Reactivity Influence of the Baking Process..478 C. Dreyer Modern Anode Baking Furnace Developments......486 F. Keller and J. Disselhorst Strategies for the Revision of Bake Furnaces ...492 F. Keller Rodded Anode Production and Anode Design Temperature and Voltage Measurements in Hall Cell Anodes.....500 R. Peterson Studies of Stub to Carbon Voltage.....510 R. Peterson Factors in the Design of Reduction Cell Anodes.....516 D. Brooks and V. Bullough Anode Cast Iron Thickness Optimization.524 M. Ohlswager, G. Goeres, and R. Peterson Drilling of Stub Holes in Prebaked Anodes.....529 B. Aga, I. Holden, H. Linga, and K. Solbu Problems of the Stub–Anode Connection.. 534 S. Wilkening and J. Côté Challenges in Stub Hole Optimisation of Cast Iron Rodded Anodes ..543 D. Richard, P. Goulet, O. Trempe, M. Dupuis, and M. Fafard Real Time Temperature Distribution during Sealing Process and Room Temperature Air Gap Measurements of a Hall– Héroult Cell Anode549 O. Trempe, D. Larouche, D. Ziegler, M. Guillot, and M. Fafard Effects of Carbonaceous Rodding Mix Formulation on Steel–Carbon Contact Resistance ....555 P. Rhedey and L. Castonguay Anode Performance: Reactivity Fundamentals Anode Carbon Reactivity.....564 S. Jones and R. Hildebrandt Studies on Anode Reactivity to Oxidant Gases 580 J. Rey Boero Some Practical Consequences of Analyses of the Carboxy and Airburn Reactions of Anode Carbons......589 N. Bird, B. McEnaney, and B. Sadler A Porosimetric Study of Sub–Surface Carboxy Oxidation in Anodes .594 B. Sadler and S. Algie Studies of the Impact of Vanadium and Sodium on the Air Reactivity of Coke and Anodes.606 J. Rolle and Y. Hoang Anode Performance: Dusting A Review of Factors Affecting Carbon Anode Consumption in the Electrolytic Production of Aluminum......611 P. Rhedey Reflections on the Carbon Consumption of Prebaked Anodes .....623 S. Wilkening Anode Dusting in Hall–Heroult Cells 633 T. Foosnaes, T. Naterstad, M. Bruheim, and K. Grjotheim The Influence of Low Current Densities on Anode Performance.643 S. Hume, M. Utley, B. Welch, and R. Perruchoud Dust Generation and Accumulation for Changing Anode Quality and Cell Parameters .649 R. Perruchoud, K. Hulse, W. Fischer, and W. Schmidt–Hatting Anode Dusting from a Potroom Perspective at Nordural and Correlation with Anode Properties657 H. Gudmundsson The Reduction in Anode Airburn with Protective Covers .....663 A. Fitchett, D. Morgan, and B. Welch Reactivity and Electrolytic Consumption of Anode Carbon with Various Additives......667 T. Müftüo—lu and H. Øye Bath Impregnation of Carbon Anodes ......673 R. Perruchoud, M. Meier, and W. Fischer Anode Performance: Thermal Shock Effects of Coke and Formulation Variables on Cracking of Bench Scale Prebaked Anode Specimens......680 D. Belitskus Thermal Shock in Anodes for the Electrolytic Production of Aluminium..687 E. Kummer and W. Schmidt–Hatting Operating Parameters Affecting Thermal Shock Cracking of Anodes in the Valco Smelter .694 N. Ambenne and K. Ries Thermal Shock of Anodes — A Solved Problem? ....700 M. Meier, W. Fischer, R. Perruchoud, and L. Gauckler Extrinsic and Intrinsic Aspects of Anode Cracking.710 T. Liu, L. Edwards, C. Hughes, B. Mason, and R. McMellon An Approach for a Complete Evaluation of Resistance to Thermal Shock (Part 1): Applying to the Case of Anodes and Cathodes ...717 C. Dreyer and B. Samanos Finite Element Modelling of Thermal Stress in Anodes.723 P. Cook Recommended Reading 731 Part 2: Hall–Héroult Cell Cathodes Section Introduction...... 739 Cell Lining: Cathodes ISO Standards for Testing of Cathode Materials .....741 H. Øye Laboratory Testing of Carbon Cathode Materials at Operational Temperatures ......747 M. Sørlie and H. Øye Structural Changes in Carbon by Heat Treatment ...754 S. Brandtzaeg, H. Linga, and H. Øye Low Electrical Resistivity and High Thermal Conductivity Carbon Products: The Solution for Cell Lining....762 D. Dumas and C. Michel Aluminium Pechiney Experience with Graphitized Cathode Blocks ..773 D. Lombard, T. Béhérégaray, B. Fève, and J. Jolas Some Experiments in Cathode Carbon .....779 S. Wilkening How to Improve the Pig Iron Sealing of Metallic Bars in Cathode Carbon Blocks .787 I. Letizia, C. Bizzarri, and M. Lezzerini Stress Analysis of Cathode Bottom Blocks ......793 B. Larsen and M. Sørlie Experimental Comparison of Cathode Rodding Practices.....799 L. Caruso, K. Rye, and M. Sørlie Cell Lining: Ramming Paste Compaction of Room Temperature Ramming Paste ......804 M. Sørlie and H. Øye Densification of Ramming Paste in Cathodes..814 M. Sørlie, B. Faaness , and J. Belmonte Investigation into the Expansion/Contraction Behaviour of Cold Ramming Pastes during Baking Using a Horizontal Dilatometer Method...... 821 B. Hocking Ramming Paste Related Failures in Cathode Linings.....827 B. Faaness, H. Gran, M. Sørlie, and H. Øye Cell Lining: Refractories Corrosion and Behaviour of Fireclay Bricks of Varying Chemical Composition Used in the Bottom Lining of Reduction Cells .. 834 F. Brunk Experiences with Dry Barrier Powder Materials in Aluminium Electrolysis Cells .. 840 O.–J. Siljan, O. Junge, T. Svendsen, and K. Thovsen Cathode Refractory Materials for Aluminium Reduction Cells....849 C. Schøning, T. Grande, and O. Siljan Evaluation of Silicon Carbide Bricks 857 A. Tabereaux and A. Fickel Quality Evaluation of Nitride Bonded Silicon Carbide Sidelining Materials ....866 E. Skybakmoen, L. Stoen, J. Kvello, and O. Darell SiC in Electrolysis Pots: An Update ..872 R. Pawlek Thermal Insulation Materials for Reduction Cell Cathodes ..876 A. Tabereaux Cathode Performance: Failure Modes Use of Cell Autopsy to Diagnose Potlining Problems ....888 R. Jeltsch Processes Occurring in the Carbon Lining of an Aluminum Reduction Cell ....894 J. Waddington A Study of Some Aspects of the Influence of Cell Operation on Cathode Life 903 C. Clelland, J. Keniry, and B. Welch Potlining Failure Modes909 M. Dell Design of Highly Reliable Pot Linings .....914 J. Peyneau Early Failure Mechanisms in Aluminium Cell Cathodes ......921 M., J. Hvistendahl, and H. Øye A Comparative Examination of Ageing of Cathodes: Amorphous Versus Graphitic Type ...931 E. Berhauser and J. Mittag Property Changes of Cathode Lining Materials during Cell Operation......936 M. Sørlie, H. Gran, and H. Øye Cathode Performance: Chemical Reactions Reaction Between Carbon Lining and Hall Bath.....946 M. Dell Penetration of Sodium and Bath Constituents into Cathode Carbon Materials Used in Industrial Cells..... 953 C. Krohn, M. Sorlie, and H. Øye Chemical Resistance of Cathode Carbon Materials during Electrolysis.....960 M. Sørlie and H. Øye The Effect of Current Density on Cathode Expansion during Start–Up......966 A. Ratvik, A. Støre, A. Solheim, and T. Foosnaes Reactions in the Bottom Lining of Aluminium Reduction Cells ..972 A. Solheim, C. Schøning, and E. Skybakmoen Chemical Degradation Map for Sodium Attack in Refractory Linings ......978 K. Tschöpe, J. Rutlin, T. Grande Cathode Performance: Erosion Physical and Chemical Wear of Carbon Cathode Materials ..984 X. Liao and H. Øye Carbon Cathode Corrosion by Aluminium Carbide Formation in Cryolitic Melts...992 X. Liao and H. Øye Erosion of Cathode Blocks in 180 kA Prebake Cells .....999 A. Tabereaux, J. Brown, I. Eldridge, and T. Alcorn Graphite Cathode Wear Study at Alouette.....1005 P. Reny and S. Wilkening Electrolytic Degradation within Cathode Materials......1011 P. Rafiei, F. Hiltmann, M. Hyland, B. James, and B. Welch Influence of Internal Cathode Structure on Behavior during Electrolysis Part II: Porosity and Wear Mechanisms in Graphitized Cathode Materials .1017 P. Patel, M. Hyland, and F. Hiltmann Influence of Internal Cathode Structure on Behavior during Electrolysis Part III: Wear Behavior in Graphitic Materials...1023 P. Patel, M. Hyland, and F. Hiltmann Spent Pot Lining Formation and Distribution of Cyanide in the Lining of Aluminum Reduction Cells...1029 R. Peterson, L. Blayden, and E. Martin Potlining Flux in Making Steel.1037 D. Augood, R. Schlager, and P. Belding Thermal Treatment of Spent Potliner in a Rotary Kiln.1044 D. Brooks, E. Cutshall, D. Banker, and D. Strahan Treatment and Reuse of Spent Pot Lining, an Industrial Application in a Cement Kiln ......1049 P. Personnet Co–Processing at Cement Plant of Spent Potlining from the Aluminum Industry.. 1057 V. Gomes, P. Drumond, J. Neto, and A. Lira Development Status of Processing Technology for Spent Potlining in China.1064 W. Li and X. Chen Recommended Reading .....1067 Part 3: Inert Anodes and Wettable Cathodes Section Introduction....1071 Inert Anodes Solubilities of Oxides for Inert Anodes in Cryolite–Based Melts ......1073 D. DeYoung Corrosion and Passivation of Cermet Inert Anodes in Cryolite–Type Electrolytes 1082 G. Tarcy Testing of Cerium Oxide Coated Cermet Anodes in a Laboratory Cell ...1094 J. Gregg, M. Frederick, H. King, and A. Vaccaro A Non–Consumable Metal Anode for Production of Aluminum with Low Temperature Fluoride Melts.1104 T. Beck The Behaviour of Nickel Ferrite Cermet Materials as Inert Anodes .1110 E. Olsen and J. Thonstad Tin Dioxide–Based Ceramics as Inert Anodes for Aluminium Smelting: A Laboratory Study...1119 A. Vecchio–Sadus, D. Constable, R. Dorin, E. Frazer, I. Fernandez, G. Neal, S. Lathabai, and M. Trigg Inert Anodes: An Update ...1126 R. Pawlek Wettable Cathodes The Application of the Refractory Carbides and Borides to Aluminum Reduction Cells ....1134 C. Ransley Use of TiB2 Cathode Material: Application and Benefits in Conventional VSS Cells..1145 L. Boxall, A. Cooke, and H. Hayden Use of TiB2 Cathode Material: Demonstrated Energy Conservation in VSS Cells 1153 A. Cooke and W. Buchta A Review of RHM Cathode Development .....1164 C. McMinn Properties of a Colloidal Alumina–Bonded TiB2 Coating on Cathode Carbon Materials.....1171 H. Øye, V. de Nora, J. Duruz, and G. Johnston Sodium and Bath Penetration into TiB2–Carbon Cathodes during Laboratory Aluminium Electrolysis ...1179 J. Xue and H. Øye Wettable Cathodes: An Update.1185 R. Pawlek Recommended Reading .....1191 Author Index. 1193

ALAN TOMSETT, PhD, is Technical Director for the Pacific Technology Center, Pacific Aluminum, where he provides technical support and advice to the Pacific Aluminum smelters. Dr. Tomsett has more than twenty-five years of experience in carbon anode and cathode technology. JOHN JOHNSON, MS, heads his own consulting business. He has forty-two years of experience in the aluminum industry, specializing in prebake and VSS anode technology as well as prebake cell design and development. Mr. Johnson was the Editor of Light Metals 2010.