The Oxidation of Pyrite in NaOH Medium

The oxidation of FeS2 presents passivation characteristic in sodium hydroxide solution due to the following reactions  

The formation of hydroxyl precipitate prevents from the transfer of electron especially between oxygen and the mineral surface. As a result of all these processes, EIS represents passivation characteristic. And the corrosive potential moves towards negatively, the surface resistance increases, and the corrosive current decreases. The formation of surface hydroxyl iron precipitates makes the pyrite surface very hydrophilic. 

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