Selective Leaching and Recovery of Collector Metals from PGM-Containing Waste Using Low-Concentration Hydrochloric Acid

The increasing global demand for platinum-group metals (PGMs) from the automotive, electronics, and hydrogen fuel-cell industries necessitates efficient recycling technologies for materials containing PGMs. This study proposes an innovative method that enhances PGM recycling by combining the pyrometallurgical and hydrometallurgical processes. This method significantly reduced the aqua-regia consumption and curbed environmental emissions, such as hazardous NO_x/SO_x emissions. In addition, it increased the iridium content in the raw material from ∼0.62 wt % to as high as 2.5 wt %, simplifying subsequent PGM extraction. Na₂CO₃ precipitation was employed to recover leached collector metals from the solution as metal oxides, achieving an exceptionally high rate of recovery (≥99%) from the selective collector-metal leachate. The proposed method promotes HCl regeneration and reuse by incorporating an acid regeneration plant, thereby laying the foundation for a closed-loop system that can significantly reduce raw material consumption and environmental emissions. This innovative approach maximizes resource efficiency by targeting the near-complete recovery of valuable metals while minimizing waste. These quantifiable improvements in recovery efficiency and environmental performance underscore the potential of this process as a sustainable and economically competitive strategy for industrial-scale PGM recycling.