A Selective Separation of Platinum Group Metals from the Fe-PGM Alloy Using Electrodeposition Combined with Electrochemical Dealloying

Abstract

In the European automotive industry, a considerable volume of recalled car catalysts stems from diesel vehicles, characterized by their high silicon carbide (SiC) content. Processing such materials poses notable challenges compared to gasoline vehicle catalysts. The presence of SiC demands additional time and energy in electric arc furnace processing, with SiC’s high melting point and strong reducing properties complicating separation. The Fe-PGM alloy obtained after pyrometallurgical treatment of these SiC-rich catalysts presents hurdles for hydrometallurgical processing. With high silicon content, the alloy resists corrosion in sulfuric acid, impeding solubility and hindering progress in the recovery process. This article explores an innovative approach for selectively extracting platinum group metals (Pt, Pd, Rh) from Si-rich Fe-PGM alloys. Traditional hydrometallurgical methods struggle due to the alloy’s near-immunity to acid leaching. The study presents chemical leaching results and proposes electrodeposition combined with electrochemical dealloying as a feasible solution. This method, aiming for selective metal separation, seeks to enhance recovery process profitability by producing pure metals.