Sorption of Ruthenium on Silica Modified with Thiourea Derivatives

Sorption of ruthenium(IV,III) from solutions of hydrochloric acid by silica modified with thiourea derivatives (N-allyl-N'-propylthiourea and N-phenyl-N'-propylthiourea) was studied. An analysis of EPR and diffusion reflection spectra showed that ruthenium sorbs in the form of mono-substituted and trans-disubstituted complexes of ruthenium(III) with the thiourea derivatives. In the presence of tin chloride, the sorption proceeds through intermediate Ru(II) complexes with tin chloride. The content of sorbed ruthenium is largely influenced by the pH of the medium, the presence of tin(II) chloride, and other factors.