Abstract:Copper smelting slag, the primary solid waste generated from pyrometallurgical copper production, is rich in valuable metals such as Cu (0.5%~4.6%) and Fe (30%~49%), making it a significant secondary resource for recovery. However, over 80% of the global copper slag is still disposed of by stockpiling, which not only occupies land resources but also poses environmental threats due to the migration and release of toxic elements like Pb and As. Efficient recovery of copper and iron from copper slag is therefore of great significance for ensuring resource security and promoting the green transformation of the nonferrous metals industry. This paper systematically reviewed physicochemical properties and mineralogical characteristics of copper smelting slag, and provided an in-depth analysis of technical principles and research status of various processes, including flotation, pyrometallurgy (reducing roasting-magnetic separation, smelting reduction, oxidizing roasting-magnetic separation), hydrometallurgy (chemical leaching, bioleaching), and combined processes. Current technologies still face common challenges such as low copper-iron separation efficiency, low iron recovery rate, and difficulties in the full-component utilization of secondary slag. On this basis, future research is prospected to focus on the synergistic extraction mechanisms of copper and iron, low-carbon intensification technologies, and stepwise utilization of full components, aiming to provide theoretical support for resources utilization, detoxification, and high-value utilization of copper smelting slag.