Transformation of Green Rust to Ferric Oxyhydroxide Due to Oxidation Reaction in Aqueous Solution Containing Zn, Sn and Sand Solid Substances

Hydroxyl-chloride green rust (GR(Cl-)) was mainly transformed to lepidocrocite (γ- FeOOH) due to the oxidation reaction via aqueous solution containing different solid substances such as metallic Zn, metallic Sn and natural sand. The particle sizes of γ-FeOOH obtained from suspensions containing Sn and natural sand were close to that obtained from the suspension without coexisting solid substances. However, particles of γ-FeOOH obtained from the suspension containing Zn were smaller than those obtained from the suspension without coexisting solid substances. In addition, the crystallite size of the former was also smaller than that of the latter. These results are probably related to the adsorption of Zn ions dissolved from the coexisting metallic Zn.