A novel method for efficiently recycling platinum group metals and copper by Co-smelting spent automobile catalysts with waste-printed circuit boards

• Published in: Journal of cleaner production Vol. 447; p. 141517
• Main Authors: Huang, Rong, Zhou, Songshan, Chen, Jiaming, Zeng, Xiangfei, Han, Yunhui, Qin, Jinchuan, Huang, Yao, Lin, Fan, Yu, Xi, Liao, Shushu, Chen, Zhiqiang, Han, Yubin, Shu, Jiancheng, Chen, Mengjun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2024
• Subjects: Co-smelting; Copper; PGMs; SACs; WPCBs; PGMs; SACs; Co-smelting; WPCBs; Copper
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2024.141517

Spent automobile catalysts (SACs) and waste-printed circuit boards (WPCBs) are key secondary resources because of the presence of the platinum group metals (PGMs), copper (Cu), aurum (Au), and argentum (Ag). To recover these resources simultaneously and efficiently, a resource-saving process for co-smelting SACs and WPCBs was proposed using Cu from WPCBs to collect PGMs, Au, and Ag. Mechanical activation was found to enhance PGMs recovery by 5-10% by disrupting the cordierite encapsulation structure, thus exposing the PGMs. Additionally, gases generated during co-smelting efficiently reduced PGMs oxides and sulfides. Under optimized conditions, recovery rates reached up to 96.31% for Pt, 97.42% for Pd, 85.28% for Rh, 86.74% for Cu, 90.06% for Au, and 83.54% for Ag, respectively. The co-smelting process facilitated the transformation of organic matter, achieving the lightning and dehalogenation of the liquid phase products with a calorific value of 23.42 MJ/kg. Vitrification of residues effectively immobilized heavy metals within the glass matrix, surpassing the standards outlined in "Technical Requirements for Solid Waste Vitrification Product" (GB/T 41015-2021). Analysis confirmed the formation of a Cu-PGMs solid solution through charge transfer from PGMs to Cu, validated by SEM-EDS and XPS. [Display omitted] •The optimal conditions for recovering PGMs, Cu, Au, and Ag through SACs and WPCBs co-smelting were investigated.•Heavy metals (e.g., Pb, As, and Cr) were solidified.•The mechanism of solid solution formation between PGMs and Cu was deduced.•The decomposition pathway of organic matter was discussed in detail.