Recovery by hydrometallurgical extraction of the platinum-group metals from car catalytic converters

The car industry is one of the technological applications which more platinum-group metals (PGM) employs. Therefore, the recovery of the PGMs from the car catalytic converters could be an important source to obtain these precious metals, with economic and environmental consequences.In this work, the car catalytic converters were characterized through different techniques as X-ray diffraction, scanning electron microscopy and inductively coupled plasma.In order to suggest an environmentally friendly method for the recovery of PGMs, some conditions such as the reagents concentration and composition, energy optimization, pre-treatment in hydrogen atmosphere and a thermal pre-treatment were studied.In addition, a new alternative to recover at least the 95% of the PGMs present in the car catalytic converters by the application of lees aggressive, corrosive or expensive reagents and conditions is proposed.

Research highlights► The PGMs are mostly located on the inner surface of the cells. ► Hydrogen thermal pre-treatment does not improve the recovery significantly. ► The addition of H2O2 as oxidant agent implies the reduction of the pollutant gases. ► The different compositions of reagents studied recover more than 95% of PGMs.