Reduction of free calcium oxide content in steelmaking slag by addition of urban sludge

Canadian Metallurgical Quarterly 2026

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Authors: Xiaoting Ju, Yilin Liu, Haixia Lan, Zhixiang Li, Xu Wang, Jiang Chang, Junfeng Li, Jiang Zhang, Jie Huang, Zhibin Yang
DOI: 10.1080/00084433.2026.2620002
Cited by: 0
References: 15

Abstract

This study addresses the poor volume stability of steel slag by modifying it with urban sludge, optimising sludge mass ratios (0.5–2.5) and roasting temperatures (1000–1200°C) to minimise free calcium oxide (f-CaO). Results show that urban sludge modification significantly reduces f-CaO to a minimum of 0.22% by promoting the formation of stable phases like Ca(Fe3 + Al)SiO6, CaAl2Si2O8, and CaFeSi2O6. Characterisation reveals migration mechanisms: Ca, Si, and Al concentrate in grains, while Fe diffuses outward with higher mass ratios. Discrepancies from thermodynamic predictions are attributed to kinetic limitations.

Fields of Study & Subjects

Recycling and utilization of industrial and municipal waste in materials production Materials Engineering and Processing Metallurgical Processes and Thermodynamics

Publication details

Journal / source
Canadian Metallurgical Quarterly
Pages
1–12
Publication date
27 January 2026
Language
EN