Kinetic Study on the Leaching of Pt, Pd and Rh from Automotive Catalyst Residue by Using Chloride Solutions

Recycling platinum group metals (PGMs) from waste and/or secondary resources is becoming quite important due to the limitation of the natural resource deposits of PGMs. Among the processes of PGMs’ recycling from secondary resources, the hydrometallurgical method draws extensive concerns, particularly for the selection of leaching solution. The present work evaluated the ability of chloride leaching solutions, i.e. HCl–H2O2 and NaClO–HCl–H2O2 to extract Pt, Pd and Rh from a kinetic point of view. The effect of temperature in the range of 277–307 K and time were also examined under the conditions of � 500 mm of particle size and 100 g L � 1 of pulp density.