Synthesis, structure, dehydration transformations and ion exchange characteristics of iron-silicate with various Si and Fe contents as mixed oxides

The synthesis of a new series of impregnated metal oxides with different Fe/Si ratios (0.5, 1 and 2) was obtained by the direct precipitation method. Physico-chemical properties and molecular formula of the obtained products were identified with different analytical techniques, such as chemical stability, XRD, IR, elemental and thermal analyses. Thermal kinetic parameters, such as order (n) and activation energy (Ea), of the solid-state phase transformations of the first dehydration process have been studied for the obtained materials from DTA thermograms. The ion exchange applications and the sorption properties of the materials with some radioactive nuclides have been studied, depending on the Fe/Si molar ratios. These investigations indicated that the ion exchange capacities as well as the selectivities of different materials towards the studied nuclides show the order Co2+ > Cs+ > Na+ at a certain pH.

Iron silicate was obtained from iron oxide impregnated with silica in different Fe/Si molar ratios. Kinetics of dehydration transformation indicated a 1st order process for different silicate ratios. Application of the materials as ion exchangers showed a high affinity for ions of different charges on increasing the solution pH as well as with the silica content increasing.Figure optionsDownload as PowerPoint slide