Patents
The invention provides a process for the recovery of Palladium as Palladium Chloride from spent silica. This invention relates to two alternative routes for the recovery of Pd from spent silica. In the first route, spent silica is thermally treated in air to partially burn the organic moiety of the complex followed by Palladium extraction by acid digestion and purification by judiciously adjusting the pH of filtrate obtained. Recovered silica retains its structure and can be re-used. Alternatively, Palladium-phthalocyanine complexes from silica are extracted by treating it with aqueous HF. Silica dissolves as H2SiF6, which is a value-added product and palladium complex is filtered off. Subsequently, Pd is recovered as PdCl2 in aqueous phase by acid digestion of insoluble phthalocyanine complexes and judiciously adjusting the pH of filtrate obtained.