METHOD OF RECOVERING PALLADIUM AND PLATINUM IN THE FORM OF HIGH-PURITY COMPOUNDS OF THESE METALS FROM PASTY PRODUCTION WASTE MATERIALS CONTAINING ACTIVE CARBON

摘要

1. The method of recovering palladium and platinum in the form of high-purity compounds of the metals from post-production materials, containing activated carbon, in the form of paste, consists in burning the carbon carrier and dissolving the remains of combustion to obtain compounds of palladium and platinum. It is characterised in that the carbon carrier is burned by placing a portion of used-up catalyst, preferably with an admixture of 0.5 percent-1 percent by mass of sodium nitrate, in the flame of a gas burner. The remains of combustion are treated with concentrated solution of hydrochloric acid with an admixture of hydrogen peroxide at the temperature close to the boiling point of the solution. The obtained mixture of chloropalladium acid and chloroplatinum acid, when the content of free hydrochloric acid in the mixture reaches the level of about 10 percent by mass, is separated by introducing saturated solution of ammonium chloride into the mixture until the entire ammonium chloroplatinate precipitates and is separated from the solution of chloropalladium acid. Then, the separated compounds of palladium and platinum undergo purification processes to obtain high-purity products.