Explorative Multiple-Case Research on the Scrap-Based Steel Slag Value Chain: Opportunities for Circular Economy

This paper analyses the scrap-based steel slag from the electric arc furnace and secondary metallurgy and proposes a framework for valorising its value chain. Toward this aim, the role of slag features, technological advancements for the treatment of slag, applications, legislation, and their value chain in the circular economy and industrial symbiosis opportunities are discussed within the proposed framework. By interviewing a group of Italian steelmakers, accounting for around 30% of Italian scrap-based steel volume, we analyse various value chain key factors, namely, technology, legislation, production volume, and economic aspects. Consequently, we assess the as-is situation of the sector and elaborate on the challenges and expectations for the future in terms of collaboration frameworks. The results show how vertical (by internal treatment) and horizontal integrations (by collaborating with other potential industries) support decisions on material flow and facilitate circularity in sharing this kind of material. The most influential enabler in a vertical integration is the economic aspect, while in the horizontal integration the enablers are the market and technology. We also address the importance of raw-material self-sufficiency through analysing closed-loop supply chains and collaborative supply-chain networks.