The monograph is a comprehensive study on the influence of carbon dust in the electrolyte on the parameters of the aluminium electrolysis process. Its effects on current efficiency, anode carbon consumption, electrolyte electrical resistance, electrolyte voltage drop and increase in Jule heat release were determined.
Monografia stanowi kompleksowe opracowanie na temat wpływu pyłu węglowego w elektrolicie na parametry procesu elektrolizy aluminium. Określono jego wpływ na wydajność prądową, zużycie węgla anodowego, oporność elektryczną elektrolitu, spadek napięcia w elektrolicie oraz wzrost ilości wydzielonego ciepła Jule'a.
- Spis treści
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1. Introduction 9
References 13
2. Carbon dust in aluminium electrolysis 15
2.1. Carbon dust – a definition 15
2.1. The formation of carbon dust 18
References 21
3. Characterization of carbon dust 24
3.1. Grain size and carbon content 24
3.2. Characterization by optical microscopy 25
3.2.1. Overview images of raw carbon dust samples 27
3.2.2. Overview images of washed carbon dust samples 28
3.3. Discussion 30
3.4. Conclusions 30
4. Influence of carbon dust contents on current efficiency and anode carbon consumption 32
4.1. Experimental 32
4.1.1. Experimental cell 32
4.1.2. Apparatus 34
4.1.3. Experimental conditions 35
4.1.4. Anodes 36
4.1.5. Carbon dust 37
4.1.6. Cell performance 38
4.1.7. Treatment of the experimental data 38
4.2. Results 41
4.3. Conclusions 49
References 50
5. The influence of carbon dust on the electrical properties of the electrolyte 52
5.1. Introduction 52
5.2. Preliminary measurements of changes in electrical conductivity/resistivity by ac method 59
5.2.1. Experimental method 60
5.2.2. Experimental cell and apparatus 60
5.2.3. Experimental conditions 62
5.2.4. Results 62
5.2.5. Summary 64
5.3. Measurements of electrical conductivity/resistivity changes by dc method 64
5.3.1. Experimental apparatus and cell 65
5.3.2. Electrolyte composition 66
5.3.3. Results 67
5.3.4. Discussion 75
5.4. The Bruggeman equation 75
5.5. Excess Joule heating due to carbon dust 77
5.5. Conclusions 79
References 79
6. Characterisation of carbon dust in the electrolyte in aluminium cells 81
6.1. Introduction 81
6.2. Study of the behavior of carbon dust in the electrolyte used for aluminium electrolysis 82
6.2.1. The first set of the experiments 83
6.2.1.1. Experimental part 83
6.2.1.2. Results of electrolysis 84
6.2.1.3. Characterization of the anode surface 86
6.2.1.4. Conclusions 106
6.2.2. The second set of the experiments 106
6.2.2.1. Experimental part 106
6.2.2.2. Results of electrolysis 108
6.2.2.3. Characterization of the anode surface 111
6.2.2.4. Conclusions 131
7. Summary conclusions 133