Recovery of platinum and palladium from spent catalysts by chlorination

Recovery of Pt was performed by two different procedures, Cl-2-CO gaseous mixture and CCl4 vapors. By the first procedure, metal extractions close to 100% were obtained at 623K and 120 min for a reactive gas ratio of 1:1. Using the second procedure, best Pt extractions were obtained after 120 minutes at 773K or after 60 min at 823K. For the second procedure, the effect of carrier gas, temperature and reaction time was studied. For the recovery of Pd, catalyst attack was performed with CL in the presence of carbon. The effect of working variables and thermal treatment with previous chlorination at different atmospheres on metal extraction was studied. FLU the variables studied proved to have major effects on Pd extraction. Results indicated that treatment in O-2 totally inhibits Pd extraction, while treatment in N-2 With traces of O-2 favors extraction as compared to O-2-free N-2.