Innovative approaches to circular economy in copper slag management: Maximizing resource efficiency and sustainability

• Circular economy transforms copper slag into valuable resource, reducing waste. • Advanced flotation recovers 98 % copper; slag reused in concrete, asphalt. • Carbon-free smelting cuts emissions, recovers 99 % iron, 98 % copper. • Global cases: India, Chile, China use slag for construction, metal recovery. • Challenges: slag variability, high costs; need R&D, policy support. This review explores innovative approaches for managing copper slag under the principles of the circular economy (Reduce, Reuse, Recycle, Recover, and Repurpose), aiming to maximize resource efficiency and sustainability. Copper slag, a by-product of copper smelting, poses both environmental challenges and resource recovery opportunities. The paper highlights advanced technologies for reducing slag generation, recovering valuable metals (e.g., Cu, Fe, and Ni), and reusing slag in construction materials such as concrete and asphalt. It also presents emerging methods like carbon-free smelting, advanced flotation, and magnetic separation, as well as design principles that enable product longevity and material circularity. Furthermore, the role of cross-industry collaboration and supportive policy frameworks is examined through international case studies. Technical and economic challenges, such as slag variability, capital costs, and market acceptance are discussed alongside recommendations for policy, research, and industrial scaling. Overall, this work provides a comprehensive roadmap for transforming copper slag into a valuable asset, aligning industrial practices with global sustainability goals.