Abstract
The paper addresses the basic mechanisms leading to the low-voltage anode effect (LVAE) as well as the high-voltage anode effect (HVAE) in aluminium electrolysis cells. The root cause of any anode effect is too low alumina concentration at the anode. By statistical treatment based on a Gaussian distribution of the alumina concentration in the bath, it was found that the onset of a HVAE takes place at higher average alumina concentration if there is a large standard deviation. By calculating the anode potential using a pragmatic numerical model, it was found that a LVAE can take place at a part of the anode as small as 0.001 m2, while the rest of the anode is at the normal anode reaction, which makes it extremely difficult to discover. It was suggested that the on-and-off current pattern observed during LVAE can be explained by alternation between blocking of the surface (AE) and normal electrolysis, induced by non-stationary mass transfer of alumina.
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References
Li W, Zhao Q, Yang J, Qiu S, Chen X, Marks J, Bayliss C (2011) On Continuous PFC Emission Unrelated to Anode Effects, Light Metals 2011, 309–314.
Åsheim H, Aarhaug T A, Gebarowski W, Sandnes E, Solheim A, Haarberg GM (2017) Partial Anode Effect in a Two-Compartment Laboratory Alumina Reduction Cell, Light Metals 2017, 525–532.
Thonstad J, Rolseth S, Keller R (2013) On the Mechanism behind Low Voltage PFC Emissions. Light Metals 2013, 883–885.
World Aluminium (Retrieved May 2021)
Espinoza-Nava L, Dubois C, Batista E (2020) Method Development to Estimate Total Low Voltage and High Voltage PFC Emissions. Light Metals 2020, 758–765.
Lavoie P, Taylor M P (2016) Alumina Concentration Gradients in Aluminium Reduction Cells, Molten 2016, 791–797 (Proceedings of the 10th International Conference on Molten Slags, Fluxes and Salts).
Chen X, Li W, Zhang Y, Qiu Z, Bayliss C (2013) Investigation on Formation Mechanism of Non-Anode Effect Related PFC Emissions from Aluminum Reduction Cells, Light Metals 2013, 877–881.
Tessier J, Cantin K, Magnússon DT Þ (2018) Investigation of Alumina Concentration Gradients within Hall-Héroult Electrolytic Bath, Light Metals 2018, 515–522.
Kolås S, McIntosh P, Solheim A (2015) High Frequency Measurements of Current through Individual Anodes: Some Results from Measurement Campaigns at Hydro, Light Metals 2015, 729–734.
Grjotheim K, Kvande H (1993) Introduction to Aluminium Electrolysis. Understanding the Hall-Héroult Process. (2nd Edition, Aluminium-Verlag, Düsseldorf, 1993)
NIST-JANAF Thermochemical Tables, https://janaf.nist.gov/ (Retrieved May 2021).
Solheim A, Sterten Å (1999) Activity of Alumina in the System NaF-AlF3-Al2O3 at NaF/AlF3 Molar Ratios Ranging from 1.4 to 3, Light Metals 1999, 445–452.
Dorreen MMR, Hyland MM, Haverkamp RG, Metson JB, Jassim A, Welch BJ, Tabereaux AT (2017) Co-evolution of Carbon Oxides and Fluorides During the Electrowinning of Aluminium with Molten NaF-AlF3-CaF2-Al2O3 Electrolyte,. Light Metals 2017, 533–539.
Kjos O, Solheim A, Aarhaug T, Osen K, Martinez AM, Sommerseth C, Gudbrandsen H, Støre A, Gaertner H (2018) PFC Evolution Characteristics during Aluminium and Rare Earth Electrolysis, Light Metals 2018, 1449–1456.
Dorreen MMR, Chin DL, Lee JKC, Hyland MM, Welch BJ (1998) Sulfur and Fluorine Containing Anode Gases Produced During Normal Electrolysis and Approaching an Anode Effect, Light Metals 1998, 311–316.
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Solheim, A. (2022). Reflections on the Low-Voltage Anode Effect in Aluminium Electrolysis Cells. In: Eskin, D. (eds) Light Metals 2022. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-030-92529-1_126
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DOI: https://doi.org/10.1007/978-3-030-92529-1_126
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