Document Type
Extended Abstract
Abstract
The transition towards more sustainable steelmaking methods, such as electric arc furnace (EAF) processes, is driving a significant increase in the production of electric arc furnace slag (EAFS). Unlike ground granulated blast furnace slag (GGBFS), a widely used by-product of traditional blast furnace-basic oxygen furnace (BF-BOF) processes, EAFS currently has limited applications, primarily as aggregate in concrete or asphalt, with large volumes landfilled. Efforts to utilise EAFS as a supplementary cementitious material (SCM) have shown mixed outcomes due to its low inherent reactivity and variability in properties. Our research focuses on developing a process to enhance the reactivity of EAFS as an SCM. Additionally, we are exploring variations such as adjusting its chemical composition and blending it with other SCMs to optimise performance. The processed EAFS achieves an amorphous content of 50–95% and promotes the formation of clinker phases, including β-belite, tricalcium aluminate, and, in some cases, alite. Our processing enables the replacement of 20–30 wt. % of ordinary Portland cement (OPC) with minimal strength loss. With targeted adjustments, replacement levels can reach up to 50 wt. %. Compared to GGBFS, our material performs similarly or better, particularly due to its enhanced early reactivity. The softness of processed EAFS also improves grindability, simplifying slag processing. These advancements position EAFS as a transformative SCM, addressing the shortage of high-quality materials, reducing industrial waste, and fostering collaboration between the steel and construction industries. This scalable innovation supports sustainable construction and advances the circular economy.
Keywords
electric arc furnace slag, EAFS, steel slag, slag valorisation GGBFS, supplementary cementitious material, SCM, optimisation, reactivity, characterisation.
DOI
10.5703/1288284317959
Enhancing the reactivity of steel slag for high-quality SCMs
The transition towards more sustainable steelmaking methods, such as electric arc furnace (EAF) processes, is driving a significant increase in the production of electric arc furnace slag (EAFS). Unlike ground granulated blast furnace slag (GGBFS), a widely used by-product of traditional blast furnace-basic oxygen furnace (BF-BOF) processes, EAFS currently has limited applications, primarily as aggregate in concrete or asphalt, with large volumes landfilled. Efforts to utilise EAFS as a supplementary cementitious material (SCM) have shown mixed outcomes due to its low inherent reactivity and variability in properties. Our research focuses on developing a process to enhance the reactivity of EAFS as an SCM. Additionally, we are exploring variations such as adjusting its chemical composition and blending it with other SCMs to optimise performance. The processed EAFS achieves an amorphous content of 50–95% and promotes the formation of clinker phases, including β-belite, tricalcium aluminate, and, in some cases, alite. Our processing enables the replacement of 20–30 wt. % of ordinary Portland cement (OPC) with minimal strength loss. With targeted adjustments, replacement levels can reach up to 50 wt. %. Compared to GGBFS, our material performs similarly or better, particularly due to its enhanced early reactivity. The softness of processed EAFS also improves grindability, simplifying slag processing. These advancements position EAFS as a transformative SCM, addressing the shortage of high-quality materials, reducing industrial waste, and fostering collaboration between the steel and construction industries. This scalable innovation supports sustainable construction and advances the circular economy.