Kinetics of the Fe3O4-Fe2O3 reaction in liquid lead-bismuth eutectic

Aleksandr Tsybanev, Kristof Gladinez, Alessandro Marino, Nele Moelans, Jun Lim

    Research outputpeer-review

    Abstract

    Liquid lead–bismuth eutectic (LBE)1 is the primary coolant for MYRRHA, an accelerator-driven system under development at SCK CEN. In LBE, the dissolved oxygen concentration (DOC)2 is a critical control parameter and it can be negatively affected by the Fe3O4-Fe2O3 reaction. In this study, the kinetics of the Fe3O4-Fe2O3 reaction on suspended Fe3O4 particles, which are naturally
    present in as-received LBE, is experimentally investigated. Due to the low concentration of these particles, an indirect method is used – coulometric oxygen titration by the electrochemical oxygen pump. The Fe3O4-Fe2O3 reaction consisted of two successive stages: a rapid surface reaction and a slow intra-particle reaction. Tests indicated that the reaction rate decreases with temperature implying a negative apparent activation energy.
    Finally, we constructed a simple adsorption model describing the surfacer reaction. The accuracy of the model was sufficiently high in the DOC range relevant for MYRRHA, 10-7-10-6 wt.% DOC.
    Original languageEnglish
    Article number121235
    Number of pages18
    JournalChemical Engineering Science
    Volume306
    DOIs
    StatePublished - 19 Jan 2025

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