Inert Anodes for Aluminum Electrolysis

Preface
Contents
Part I: The Development of Inert Anodes for Aluminum Electrolysis
Chapter 1: Research Background of Inert Anodes for Aluminum Electrolysis
1.1 The Development of Aluminum Metallurgy
1.2 Development of Aluminum Electrolytic Cells and Anodes
1.3 Three Parts of Prebaked Cells
1.3.1 Anode Device
1.3.2 Cathode Device
1.3.3 Conductive Busbar System
1.4 Aluminum Reduction Cell Series and Potroom Building
1.4.1 Aluminum Reduction Cell Series
1.4.2 Aluminum Potroom
1.5 Carbon Anode Production Process
1.5.1 Aggregate—Calcined Petroleum Coke and Coal Tar Pitch
1.5.2 The Quality Standards of Carbon Anode
1.5.2.1 Anode Paste
1.5.2.2 Prefabricated Anode Block (Carbon Anode)
1.6 Cryolite and Aluminum Fluoride Production
References
Chapter 2: Aluminum Electrolysis Production Process
2.1 Normal Production of Aluminum Electrolysis Cells
2.2 Technical Conditions for Normal Production of Aluminum Electrolysis
2.3 Conventional Operation of Aluminum Electrolysis
2.3.1 Feeding of the Raw Material
2.3.2 Aluminum Tapping
2.3.3 Anode Changing
2.3.4 Computer Control of Aluminum Reduction Cells
2.4 The Gas Purification of Aluminum Plant Anode
2.4.1 Pollutants in the Anode Gas of Aluminum Plants
2.4.2 Method of Anode Gas Purification in Aluminum Plants
2.4.2.1 Wet Purification
2.4.2.2 Dry Purification
2.5 Economic Analysis of Primary Aluminum Production
2.5.1 Cost Analysis of Primary Aluminum Production
2.5.2 Ways to Reduce Costs
2.5.2.1 Reducing the Loss of Raw Materials
2.5.2.2 Strengthening Production Management and Extending the Effective Production Time of the Electrolytic Cells
References
Part II: Review of the Study on the Inert Anode of Aluminum Electrolysis
Chapter 3: Aluminum Electrolytic Inert Anode
3.1 Disadvantages of Current Hall-Heroult Aluminum Electrolysis Process
3.1.1 Carbon Anode Consumption
3.1.2 Poor Wettability of Carbon Cathode and Liquid Aluminum
3.1.3 Other Problems with Carbon-Lined Materials
3.1.4 Horizontal Structure of Hall-Heroult Electrolyzer
3.2 Study on Inert Anode
3.2.1 Advantages of Inert Anodes
3.2.2 Performance Requirements and Research Survey of Inert Anode
3.2.2.1 Definition of Inert Anode
3.2.2.2 The Criteria for Inert Anode Materials
3.2.3 Certain Candidate Materials for Manufacturing Inert Anodes
3.2.3.1 Oxide Materials
3.2.3.2 Ceramic Materials
3.3 Detection and Testing of Inert Anodes
3.3.1 Three-Electrode Cell Detection of Inert Anode
3.3.2 Inert Anode Electrolytic Test Cell
3.3.3 The Solubility of Inert Anode Materials in Cryolite Melts
3.3.4 Corrosion and Passivation of Ceramic Inert Anode During Electrolysis in Cryolite Melt
3.3.5 Corrosion Test Cell
3.3.6 Test Cell for Long-Time Electrolysis
3.3.7 Newly Developed Inert Anode
3.4 Research Progress of Inert Anodes in Recent Years
3.4.1 Metal Oxide Ceramic Anode
3.4.2 Spinel (AB2O4) Composite Metal Oxide Anodes
3.4.3 SnO2-Based Metal Oxide Anodes
3.4.4 CeO2-Coated Anode
3.4.5 Other Metal Oxide Electrodes
3.5 Study on Alloy Anode
3.5.1 Cu-Al Alloy Anode
3.5.2 Ni-Fe-Based Alloy Anode
3.6 Study on Cermet Anode
3.6.1 NiFe2O4-Based Cermet
3.6.2 Experimental Study on Electrolytic Cell of Cermet Inert Anode at Initial Stage
3.6.3 Test of 2500 A Inert Anode Electrolyzer
3.6.4 The Relationship Between Composition of the Inert Anode and the Corrosion Resistance of NiFe2O4-Based Cermet
3.6.4.1 The Effect of Ceramic Phase Composition on Corrosion Resistance
3.6.4.2 Effect of Metal Phase Composition on Corrosion Resistance
3.6.5 Corrosion Mechanism of NiFe2O4-Based Cermet Inert Anodes
3.6.5.1 Chemical Corrosion
Chemical Dissolution
Aluminothermic Reduction
Intergranular Corrosion and Electrolyte Infiltration
3.6.5.2 Electrochemical Corrosion
3.6.6 Preparation of Inert Anode for NiFe2O4-Based Cermet
3.6.7 Sintering Densification of NiFe2O4 Based Cermet Inert Anode
3.6.8 Mechanical Properties of NiFe2O4-Based Cermet Inert Anode
3.6.9 High-Temperature Oxidation Resistance and Electrical Conductivity of NiFe2O4-Based Cermet
3.6.10 Connecting Technology of Inert Cermet Anode and Metal Guide rod
3.6.10.1 Mechanical Connection
3.6.10.2 Welding Connection
3.7 Low-Temperature Aluminum Electrolysis
3.7.1 NaF-AlF3 Low-Temperature Electrolyte System
3.7.2 KF-AlF3 Low-Temperature Electrolyte System
3.7.3 Main Problems That Need to Be Solved in Low-Temperature Aluminum Electrolysis of Inert Anode
3.7.3.1 Alumina Dissolution
3.7.3.2 Electrolyte Cathodic Shell
3.7.3.3 New Cathode and Lining Material
3.7.3.4 Other Problems
3.8 Study on Inert Wettable Cathode
3.8.1 Advantages of Inert Wettable Cathode
3.8.2 Requirements and Research Situation of Inert Wettable Cathode
3.8.3 TiB2 Ceramic Wettable Cathode Material
3.8.4 TiB2-C Composite Wettable Cathode Material
3.8.5 TiB2 Wettable Cathode Coating Material
3.9 The New Type of Electrolysis Cell Based on Inert Electrode (Anode and Cathode)
3.9.1 Electrolytic Cell with Inert Anode
3.9.2 Electrolytic Cell Using Wettable Cathode Alone
3.9.3 Mushroom Cathode Electrolysis Cell
3.9.4 Conducting Aluminum Electrolytic Cell with Carbon Anode (Flame Diversion Trough)
3.9.5 Electrolytic Cells that Combine Inert Anode and Wettable Cathode
3.9.5.1 Inert Anode Diversion Trough for Monopolymer Aluminum Ditch
3.9.5.2 An Inert Anode Electrolysis Cell for Polyaluminum Channel
3.9.6 An Inert Anode Aluminum Electrolysis Cell with Complex Structure
3.9.7 Slurry Electrolyzer
3.9.8 The Future Development of New Aluminum Reduction Cell
3.10 Recent Research and Development of Aluminum Electrolytic Inert Anodes
3.10.1 Cermet
3.10.1.1 Regulation and Control of Sintering Atmosphere
3.10.1.2 Mix Doping
3.10.2 Alloy Inert Anode
3.11 Engineering Tests
3.11.1 Cermet Inert Anode
3.11.1.1 Results
3.11.2 Alloy Anode
3.11.3 Environmental Protection
References
Part III: Study on Nano-ceramic Inert Anode
Chapter 4: Nanomaterials and Nano-cermet
4.1 Introduction
4.2 Nanomaterials
4.3 Nano-ceramics
4.4 Nanocomposite Ceramics
4.4.1 Definitions of Nanocomposite Ceramics
4.4.2 Classification of Nanocomposite Ceramics
4.5 Nano-cermet
4.5.1 Definition of Nano-cermet
4.5.2 Design of Nano-cermet Inert Anode
4.6 Process for Preparing Nano-cermet Inert Anode
4.7 X-Ray Diffraction Analysis
4.8 Metallographic Structure Observation
4.9 The Determination of Electrical Conductivity
4.10 Corrosion Rate
4.11 Conclusions
References
Chapter 5: Measurement of Mechanical Properties for NiFe2O4 Nano-cermet
5.1 Preparation of Nano-cermet Inert Anode Samples
5.1.1 Later Processing of Samples
5.1.1.1 Coarse Grinding
5.1.1.2 Fine Grinding
5.1.1.3 Polishing
5.2 Structural Characterization of Nano-cermet Specimen
5.2.1 X-ray Diffraction Analysis Principle
5.2.2 Analysis of X-ray Diffraction
5.3 Testing of Mechanical Properties of NiFe2O4 Nano-cermet
5.3.1 Hardness Test of NiFe2O4 Nano-cermet
5.3.1.1 Hardness Measurement Method
5.3.1.2 Principle of Micro Vickers Hardness Measurement
5.3.1.3 Experimental Procedure
5.3.1.4 Experimental Result
5.3.2 Bending Strength Test
5.3.2.1 Three-Point Bending Test Principle
5.3.2.2 Test Step
5.3.2.3 Experimental Results and Analysis
5.3.3 Testing of Fracture Toughness
5.3.3.1 Significance of Fracture Toughness Testing
5.3.3.2 Fracture Toughness Testing Method
5.3.3.3 Vickers Indentation Method
5.3.3.4 Single-Edge Notched Beam Method
5.3.4 Experiment of Fracture Toughness
5.3.4.1 Experimental Procedure
5.3.5 Experimental Results and Analysis
5.4 Microstructure Analysis of NiFe2O4 Nano-cermet
5.4.1 Toughening Mechanism of Nanocomposite Ceramics
5.4.2 Microcrack Toughening Mechanism
5.4.3 Crack Deflection and Crack Bending Toughening Mechanism
5.4.4 Crack Bridging Toughening Mechanism
5.5 Observation and Analysis of Fracture Morphology of NiFe2O4 Nano-cermet
5.5.1 A Brief Introduction to the Structure and Working Principle of Scanning Electron Microscopy (SEM)
5.5.2 Test Result Analysis
5.5.2.1 Density
5.5.2.2 Fracture Mode
5.5.2.3 Crack Toughening
5.6 Conclusions
References
Index