Copper Slag as a Source of Iron: An Overview

The production of Copper slag occurs during the smelting of Cu, and it contains various compounds, including oxides of Fe, Cu, Co, Al, Si, Ni, Cr, and Ca. A significantly smaller percentage is utilised for low-end applications and is mainly dumped, thus occupying large spaces for a longer duration. As a result, gainful utilization of such slag into value-added products is necessary to avoid the associated environmental hazards and economic loss. Notably, Cu slag possesses more valuable metals like Cu and Fe than certain raw ores. This paper explores methods for recovering and treating copper slag. Metal recovery has been a focal point in recent decades but comes with challenges. The process consumes significant energy, and its low recovery ratio hampers the advancement of recovery technologies, making them economically impractical and difficult to implement on an industrial scale. The high temperature of copper slag derived from furnaces (>1300 °C) indicates the potential for reclaiming substantial energy. Integrating waste heat and metal recovery techniques makes it possible to address the issues above. However, most research on recovery lacks an economic analysis of their technologies. Due to its high Fe content, copper slag can be a Fe-adjusting material in cement clinker production. However, before utilizing Cu slag as a material resource, it is crucial to perform simultaneous metal extraction.