Self-catalytic oxidation enables metal recovery from copper smelting flue dust

With the rapid expansion of global copper production, large quantities of copper smelting flue dust (CSFD) are generated as a hazardous yet metal-rich by-product. However, current recovery methods are limited by high energy consumption, secondary pollution, and low leaching efficiency. Here, we introduce an self-catalytic leaching strategy based on ammonium persulfate ((NH₄)₂S₂O₈) that operates without external catalyst addition. This approach enables efficient leaching of Cu (98.7%), Zn (98.1%), and As (85.3%) within 60 min under mild conditions. The process is intrinsically driven by Cu⁺ species present in CSFD, which activate (NH₄)₂S₂O₈ to generate SO₄·^- and ·OH radicals. These reactive species (RS) act synergistically to oxidize S^2- into SO₄^2-, thereby facilitating the effective release and leaching of Cu, Zn, and As. An economic assessment further demonstrates the promising practical potential of this system, with significantly reduced energy consumption and improved economic value. This study provides fundamental insights into the role of self-catalytically generated RS in metal leaching and offers a sustainable strategy for resource recovery, contributing to the advancement of circular economy practices.