Characterization of steel slag for the production of chemically bonded phosphate ceramics (CBPC)

This work studies the use of steel slag as a source of metallic oxides for the synthesis of chemically bonded phosphate ceramics (CBPCs). Analysis of different slags revealed characteristics, relating to alkaline character, granulometry and metallic oxide content, which could enable their use other than as construction aggregates. Steel slags from an electric arc furnace (EAF) and basic oxygen furnace (BOF), as well as ladle furnace basic slag (LFS), were collected from steel plants in Colombia following the ASTM D75 standard practice for aggregate sampling. The slags were analysed through techniques such as SEM/EDS, FTIR, XRD and XRF, finding considerable quantities of CaO and iron oxides that provide the necessary metallic cation in acid-base reaction systems. The formation of phosphate ceramics was achieved from steel slags, compression strengths of up to 20 MPa were reached at 35 days and the chemical stability of the cements obtained was evaluated. Additionally, physical properties important to the formation of chemically bonded phosphate ceramics (CBPCs), such as specific gravity, grain size and pH, were determined. (C) 2020 Elsevier Ltd. All rights reserved.