Patent ID: 7108839

Claim:
A process for the recovery of palladium as its salt from palladium complex adsorbed on spent silica gel, said process comprising steps of: a) burning the spent silica gel with palladium complex adsorbed on its surface, in a furnace in the temperature range of 300–700° C. in presence of air for a period ranging between 2 and 8 hours to oxidize the organic compound in the complex; b) cooling the burnt residue of step (a), digesting with a mineral acid at a temperature range of 70–100 C. for a time period of 1–6 hours to form a solution; c) cooling the solution of step (b) to an ambient temperature; d) filtering the cooled solution of step (c) to obtain a filtrate and a residue; e) washing the residue of step (d) with a mineral acid and drying at 60–100 to recover silica; f) adjusting the pH of the filtrate of step (d) to obtain a precipitate, filtering to remove the precipitate to obtain a further filtrate; and g) further raising the pH of the further filtrate obtained in step (f) to obtain a palladium salt.