Feasibility and Sustainable Utilization of Cupola Slag for Eco-Friendly Industrial Waste Management

Cast iron remains one of the most widely used alloys in modern industrial applications, with cupola furnaces being the most economical and commonly employed melting units. The melting of pig iron, scrap metal and flux in a cupola furnace generates a significant quantity of oxidized by-product known as cupola slag, which is presently classified as industrial waste and predominantly disposed of in landfills, posing environmental concerns. This study aims to systematically evaluate the potential of cupola slag as a sustainable construction material by comparing its characteristics with established industrial by-products, such as fly ash and ground granulated blast furnace slag. The physical and chemical properties of cupola slag were analysed using standard testing methods, with its chemical composition determined by X-ray fluorescence spectroscopy. The R3 reactivity test classified cupola slag as a pozzolanic, low-reactivity material. Leachability tests confirmed that the slag is non-toxic and complies with regulatory limits for hazardous elements. A life cycle assessment revealed that landfill disposal of cupola slag results in a global warming potential of approximately 32.12 kg CO2-equivalent per kilogram of slag. Furthermore, a comparative performance evaluation was conducted to assess its suitability as a partial or full replacement for cement and natural aggregates in concrete. The results demonstrate that cupola slag exhibits promising potential as a sustainable supplementary material in cement concrete, offering significant environmental benefits by reducing landfill disposal, conserving natural resources and promoting eco-friendly construction practices.