ABSTRACT
Anion and cation exchange resins have been used for analytical separations of Silicon (Si) from accompanying elements. Most of the anion exchange procedures are based on the adsorption of silicate or fluorosilicate, while the nonadsorption of these two anionic species on cationic resins serves to separate Si from essentially all cationic components of the solutions. Soluble silicate is appreciably retained by strongly basic anion exchange resins in the hydroxide forms from weakly alkaline media. No adsorption of silicate occurs on strongly basic resins in the sulfate form or from very dilute sulfuric acid media. Since Si is in solution usually present as an oxyanion species, this element is not adsorbed on cation exchange resins. Therefore, separations of Si on exchangers of this type are based on the adsorption of accompanying constituents in solutions from which strong adsorption of the metal cations occurs.
