Recovery of Platinum Group Metals from Spent Catalysts Using Electroless Nickel Plating and Magnetic Separation

Abstract

This study demonstrates a new process for physically recovering platinum group metals (PGMs) directly from spent automobile catalysts. Automobile catalysts mostly consist of a honeycomb-structured ceramic substrate coated with a porous catalyst layer supporting ne particles of Pt, Pd, and Rh. In the proposed process, in order to magnetically separate and concentrate the PGMs, ferromagnetic Ni is deposited on the PGM particles (or the catalyst layer) using an electroless plating technique. Experiments were performed using samples that simulated an automobile catalyst. Using the electroless plating process, Ni could be coated on the porous catalyst layer without requiring complicated pretreatments such as sensitization and activation. Furthermore, the PGMs (Pt, Pd, and Rh) could be extracted and concentrated in the form of a magnetic powder through magnetic separation performed after Ni deposition and subsequent pulverization. Thus, the proposed physical concentration process is feasible and effective, and this process can be extended for making the recycling of automobile catalysts more ef cient and environmentally friendly.

Platinum Recovery Techniques for a Circular Economy

“…In the last decade, numerous techniques have been introduced as more environmentally affordable Pt recovery methods [101]. Taninouchi et al used magnetic separation to concentrate Pt before its further leaching treatment through Ni electro-less or FeCl 2 vapor deposition [102,103]. Pt and other PGM were successfully alloyed forming magnetic compounds that were separated from the rest of the catalyst, in this way, the quantity of the sample that has to be further treated diminishes and the energetic and reagent consumption do so.…”

Trends of Technological Development of Platinum Group Metal Recycling: Solubilization and Physical Concentration Processes

“…Fig. 11 Schematic illustration of the novel technique for physically separating PGMs from spent catalysts [68][69][70] . In this technique, PGMs are concentrated magnetically by depositing a ferromagnetic metal such as Fe or Ni on the catalyst layer using electroless plating.…”

Recovery of Noble Metals from Spent Catalysts: A Review

“…Taninouchi et al [83] came up with a new process (Figure 8), where a magnetic separation technique is used to recover the PGMs from spent catalysts. showing strong ferromagnetic character.…”