Structural characteristics and cementitious behavior of basic oxygen furnace slag mud and electric arc furnace slag: Fid-Bau Portal

Structural characteristics and cementitious behavior of basic oxygen furnace slag mud and electric arc furnace slag

Zhang, Na / Wu, Le / Liu, Xiaoming / Zhang, Yihe

Highlights • The cementitious activity of basic oxygen furnace (BOF) slag mud is much lower compared to electric arc furnace (EAF) slag. • BOF slag mud is not suitable for being utilized as mineral admixture. • EAF slag exhibiting appropriate cementitious activity, can be utilized as mineral admixture in cement and concrete. • Particular attention should be paid to solidify phosphorus of EAF slag to avoid retarding effect in cement and concrete.

Abstract Basic oxygen furnace (BOF) slag mud and electric arc furnace (EAF) slag were characterized by TG-DSC, XRD, FTIR, ²⁷Al MAS-NMR and ICP-MS techniques to correlate structural characteristics with cementitious behavior. BOF slag mud is a by-product discharged after the wet milling and magnetic separation of basic oxygen furnace steel slag. Due to the cementitious phases of C2S and C3S have been hydrated during the wet milling process to form Ca(OH)2 and C-S-H in the BOF slag mud, the cementitious activity of BOF slag mud is much lower than that of EAF slag. Considering the higher water absorption capacity and lower contents of C2S, C3S and tetrahedrally coordinated Al in the BOF slag mud, it is thought that BOF slag mud is not suitable for being utilized as mineral admixture; while the EAF slag, exhibiting appropriate cementitious activity, can be utilized as mineral admixture in cement and concrete. Particular attention should be paid to solidify phosphorus of EAF slag to avoid retarding effect in the hydrated system of blended cement and concrete.