Essential Readings in Light Metals Electrode Technology for 4 VOLUME Aluminum Production Edited by Alan Tomsett John Johnson and Copyright © 2013 by The Minerals, Metals & Materials Society. All rights reserved. Published by JohnWiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada. 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ISBN 978-1118-63663-3 Printed in the United States of America. 10 9 8 7 6 5 4 3 2 1 TABLE OF CONTENTS 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. Rhedeyand S. Nadkarni Quality and Process Performance of Rotary Kilns and Shaft Calciners....................................................................................24 L. Edwards High Vanadium Venezuelan Petroleum Coke, A Rawmaterialfor 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 Performance.........................................................................................................42 S. Jones, R. Hildebrandt, and M. Hedlund CarbonRaw Material Effects on Aluminum Reduction Cell Anodes.......................................................................................53 P. Rhedeyand S. Nadkarni A Comprehensive Determination of Effects of Calcined Petroleum Coke Properties on Aluminum Reduction Cell Anode Properties...................................................................................................................................................................................59 D. Belitskusand D. Danka A Comprehensive Review of the Effects of Calcination at Various Temperatures on Coke Structure and Properties (cid:2) 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. Costeand J. Schneider Coke CalcinationLevels 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. Samanosand C. Dreyer xiv v 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. Garbarinoand 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 Materials......................................................................156 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 Anodes.......................................................................................................................167 R. Perruchoud, M. Meier, and W. Fischer Coal Tar Pitch (cid:2) Past, Present, and Future...............................................................................................................................177 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. Jonesand E. Bart Binding Characteristics of Coal Tar Pitches for Prebaked Anode Mix - Choice Criteria: LRF Report830............................215 J. Pinoirand 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 SøderbergAnode Pitch....................................................................................................................239 M. Sørlie xv vi Developing Coal Tar/Petroleum Pitches..................................................................................................................................246 R. Womblesand 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. Fischerand 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. Houstonand H. Øye Characterization of Prebaked Anode Carbon by Mechanical and Thermal Properties............................................................298 J. Brownand P. Rhedey Green Anode Production Aggregate Optimization Using a Y-Blender............................................................................................................................307 R. Peterson Soderberg Paste. Effect of Fine Fraction Variations................................................................................................................313 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 (cid:2) Why We Need Statistical Thinking in Operations Such as Carbon Plants...........................................365 K. Sinclairand B. Sadler xvi vii 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 Furnaces........................................................414 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 onBaking.........................................................................................................................................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 Sloughing......................................................................450 E. Cutshalland 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. Kellerand J. Disselhorst Strategies for the Revision of Bake Furnaces..........................................................................................................................492 F. Keller xvii viii 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. Wilkeningand 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 SealingProcess and Room Temperature Air Gap Measurements of a Hall- Héroult Cell Anode..................................................................................................................................................................549 O. Trempe, D. Larouche, D. Ziegler, M. Guillot, and M. Fafard Effects of Carbonaceous Rodding Mix Formulation on Steel-Carbon Contact Resistance.....................................................555 P. Rhedeyand 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. Sadlerand S. Algie Studies of the Impact of Vanadium and Sodium on the Air Reactivity of Coke and Anodes..................................................606 J. Rolleand 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 xviii ix 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 Properties..........................................657 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(cid:2)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. Kummerand W. Schmidt-Hatting Operating Parameters Affecting Thermal Shock Cracking of Anodes in the Valco Smelter..................................................694 N. Ambenneand K. Ries Thermal Shock of Anodes (cid:2) 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 Evaluationof Resistance to Thermal Shock(Part 1): Applying to the Caseof Anodes and Cathodes..............................................................................................................................................................717 C. Dreyerand 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 xix x Laboratory Testing of Carbon Cathode Materials at Operational Temperatures.....................................................................747 M. Sørlieand 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 GraphitizedCathode 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. Larsenand 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. Sørlieand 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. Tabereauxand A. Fickel Quality Evaluation of Nitride Bonded Silicon Carbide Sidelining Materials..........................................................................866 E. Skybakmoen, L. Stoen, J. Kvello, and O.Darell xx xi 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 Modes...........................................................................................................................................................909 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. Berhauserand 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 duringElectrolysis..................................................................................960 M. Sørlieand 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. Liaoand H. Øye xxi xii