Synthesis, ion exchange properties and analytical applications of stannic silicomolybdate: Effect of temperature on distribution coefficients of metal ions

Stannic silicomolybdate was synthesized at pH 0.63 .The experimental parameters such as order of mixing, mixing volume ratio, pH, stirring time, drying temperature were established for the synthesis of the material. The ion exchange capacity of Ca2+ was improved from 0.53 to 1.73 meq/g for this newly synthesized material. The reproducibility of the product formed was checked. The exchanger was characterized on the basis of chemical composition, thermal and chemical stability, FTIR, TGA, DSC, X-ray and SEM analysis. The scanning electron microscopy of the material shows a regular diamond shape morphology. The presence of uniform morphology also indicated the absence of impure phases. The X-ray diffraction study showed the amorphous nature. Distribution coefficient studies of the metal ions on this material were performed in solvents having different acid dissociation constants namely trichloroacetic acid, formic acid and acetic acid. The effect of dielectric constants of solvents was studied by using dimethylsulfoxide; formic acid, acetic acid and trichloroacetic acid. The effect of temperature on the distribution coefficient was explored. It was finally concluded that 45 °C appeared to be the most favorable temperature. Important quantitative separations of metal ions in ternary mixtures included Ni2+-Co2+-Pb2+, Cu2+-Cr3+-Pb2+, Cu2+-Fe3+-Pb2+, Th4+-Zr4+-Sn4+, Cr3+-Ni2+-Fe3+, Cu2+-Ni2+-Ag+ and Fe3+-Zn2+-Al3+. The practical potential of stannic silicomolybdate was explored by separating Cu2+ and Zn2+ quantitatively in synthetic mixtures as well as in commercially available brass samples.