Microsphere Zirconomolybdate Sorbents for Extraction of Lanthanides (III) from Aqueous Solutions
Micromesoporous zirconomolybdates with a specific surface area of 200 m2/g and pore sizes in the range of 10-40 Å (Dmax~15 Å) were synthesized under hydrothermal conditions (150 °С, 72 h). Microsphere composites were prepared by deposition of the zirconomolybdates on a microsphere hollow carrier with a macroporous shell (Dpore ~ 2-10µm) resulted from the NH4F-HCl-H2O etching of a cenosphere narrow fraction (-0,08+0,071 mm) separated from coal fly ash of Reftinskaya power station. The morphological type “cenospheres with a porous shell and a smooth surface” predominates in the fraction. The sorption properties of zirconomolybdates and microsphere composites with different Mo/Zr ratio were studied regarding Nd3+ cations as a surrogate of trivalent actinides. It was established that the thin-layer mode of zirconomolybdate deposition on the carrier and the increasing of a Mo/Zr ratio in its composition provides the enhanced distribution coefficient (up to 104 ml/g) and efficiency of Nd3+ sorption (up to 85 %).