Scrap Catalytic Converters may be accumulated at automotive repair shops and auto salvage yards
The whole converters can be sold AS IS for scrap or may be De-Canned to recover the auto catalysts.
Recoverd catalyst may be accumulated and sent to a precious metal refinery to recover the metal values.
Petrochemical refineries are an alternative source of Spent Catalyst
Metal Content Residues may be recovered that contain Exotic Metal Scrap.
You may wish to explore the recovery of base metals from residues and sludges such as Aluminum Dross, Copper, Brass & Bronze Dross or materials containing Tin, Lead and Zinc,.