A PROCESS FOR THE RECOVERY OF ADSORBED PALLADIUM FROM SPENT SILICA

摘要

The present invention relates to a process for the recovery of precious meta ls from spent catalysts or adsorbent or inorganic waste. More specifically a process is provided for the recovery of palladium from silica, which is used as an absorbent in column chromatography or as a catalyst support in many catalysts. The process includes burning the spent silica to oxidize the organic component of the adsorbed Pd-complex, digesting the cooled residue with a mineral acid, filtering the obtained solution to separate out silica residue, adjusting the pH of the filtrate to remove precipitate impurities a nd raising the pH of the purified filtrate to recover a palladium salt.