Abstract
During molten salt electrolysis of rare earths greenhouse gas emission occurs causing environmental and climate changes. In this study the electrochemical process window for didymium oxy-fluoride electrolysis is determined by linear sweep voltammetry and staircase chronoamperometry. Simultaneously the composition and the quantity of gas generation are investigated by an in situ FTIR-spectrometry in order to understand the process phenomena happening at anode and the mechanisms behind them. Different electrolyte compositions based on NdF3, PrF3 and LiF and various oxide amounts were employed showing the diversity in off-gas ratios. Effects of using two praseodymium-oxide compounds, namely Pr6O11 and Pr2O3 used as raw materials, on the process and amount of anodic gases is considered as well. Perfluorocarbon (PFC) emission reduction is accomplished by electrolysis automatization by coupling the FTIR-spectrometer with a controller which triggers the oxide dosage preventing full anode effect.
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Acknowledgements
This work was supported by the FP-7 EU Program Grant No. 309373 ‘‘Development of a Sustainable Exploitation Scheme for Europe’s rare earth Deposits’’ (EURARE).
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Milicevic, K., Feldhaus, D., Friedrich, B. (2018). Conditions and Mechanisms of Gas Emissions from Didymium Electrolysis and Its Process Control. In: Martin, O. (eds) Light Metals 2018. TMS 2018. The Minerals, Metals & Materials Series. Springer, Cham. https://doi.org/10.1007/978-3-319-72284-9_187
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DOI: https://doi.org/10.1007/978-3-319-72284-9_187
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