Interactions between iron oxides and silicates

Abstract: The main objective of this Licentiate thesis was to acquire a better understanding of the mechanisms involved in the sorption of dissolved silicate from aqueous solutions onto iron oxide surfaces by using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and subsequently to develop a method to monitor the orientation of bentonite platelets settling onto the bare iron oxide using polarized ATR-FTIR technique. The infrared spectra show that the silicate concentration and pH both determine the species of sorbed silicate on the iron oxide surfaces. In the last part of this thesis, the orientation of bentonite platelets on a ZnSe ATR crystal as well as on a layer of magnetite particles deposited on the crystal was analyzed with polarized horizontal ATR-FTIR Spectroscopy.The iron oxide layer contributed to an increased order of the settled bentonite platelets.