Noble Metal Recovery from Spent Automotive Catalysts 820187

This paper consists of two principle parts. In Part I, the known processes for the recovery of noble metals from supported catalysts are reviewed. Part II of this paper details the development and application, on a laboratory scale, of a platinum and palladium recovery process based on a solution extraction process. Several variables for the solution extraction process were evaluated. These variables included choice of oxidant, extraction time and temperature, physical state of the catalyst pellets, and potential pretreatment steps. The best recovery of both platinum and palladium was obtained by extraction with 1-5% (v/v) nitric acid in 6 M hydrochloric acid yielding platinum and palladium recoveries of 85-95% and 89-99%, respectively, for a series of used catalysts with varying accumulated mileages.