Abstract:The production and stockpiles of copper slag in China continue to increase, posing significant challenges for large-scale treatment. Copper slag contains valuable elements including copper, iron, lead, and zinc. Most enterprises employ a slow cooling-grinding and flotation process to recover copper, while iron (with content exceeding 40%) and other resources in the resulting tailings remain largely abandoned. Numerous scholars have investigated the resource utilization of copper slag, with existing methods primarily encompassing beneficiation enrichment, hydrometallurgical leaching, pyrometallurgical treatment, direct utilization processes, and combined processes. Iron in copper slag primarily exists in the form of fayalite and magnetite. The magnetic concentrate obtained through magnetic separation often contains elevated levels of lead and zinc, making it unsuitable for direct application in blast furnace production. Although direct resource utilization represents an effective approach for large-scale copper slag utilization, the fluctuating composition of copper slag complicates this strategy. Controversies persist regarding the environmental release of arsenic and other hazardous elements during applications such as building materials, cement production, and mine backfill applications. The critical challenge for iron recovery lies in decomposing the fayalite. Methods such as alkali leaching-acid decomposition and reduction/oxidation treatments can effectively decompose and transform the fayalite phase, enabling subsequent iron recovery through smelting or magnetic separation processes. Nevertheless, treatment processes must account for the impacts of harmful elements like arsenic on both iron extraction efficiency and product quality. The integration of multiple processes emerges as an effective strategy to achieve comprehensive recovery of valuable components in copper slag while enabling tailings recycling. The combination of multiple processes serves as an effective approach for achieving comprehensive recovery of valuable components from copper slag and realizing resource utilization of tailings. Subsequent efforts should persistently strengthen research on theoretical frameworks for efficient copper slag recovery technologies, equipment research, and strategic development pathways. It is imperative to actively broaden application channels for comprehensive copper slag utilization, expand the scale of integrated utilization, and enhance the utilization efficiency of mineral resources.
