Preparation and properties of Zr-bearing sorption materials based on coal fly ash microspheres

Abstract

The influence of hydrothermal conditions on synthesis of analcime and a composite material ZrO2analcime as well as zirconomolybdate coverings with ion exchange properties was studied using narrow fractions of aluminosilicate microspheres with a high content of a glass phase (91-95 wt. %). The possibility to synthesize ZrO2-analcime composites of narrow particle size distributions with maximum of about 40 µm and 6 µm under hydrothermal treatment at 150 °С was demonstrated starting from microspheres with Si/Al=2.7 and applying different regimes of a reaction mixture agitation. A microsphere material of a “core-shell” type such as ZrMo2O7(OH)2(H2O)2@(SiO2-Al2O3)glass with the nanostructured covering was prepared. Sorption properties of the materials regarding Nd3+, Sr2+ and Cs+ were studied under equilibrium conditions by means of determination of sorption isotherms and their fitting by the Langmuir model. Sorption parameters were determined including distribution coefficients which reach the values of 104−105 mL/g.