Development of magnesium slag–steel slag-based composite cementitious material and its backfilling application

• Published in: Archives of Civil and Mechanical Engineering Vol. 25; no. 4; p. 194
• Main Authors: Zhang, Xizhi, Yang, Xiaobing, Yang, Jian, Yin, Shenghua, Bian, Wenhui, Qi, Yaobin
• Format: Journal Article
• Language: English
• Published: London Springer London 07.06.2025; Springer Nature B.V
• Subjects: Blast furnace slags; Cement; Civil Engineering; Desulfurizing; Engineering; Environmental protection; Fillers; Gypsum; Hydration; Innovations; Magnesium; Mechanical Engineering; Mechanical properties; Mineral resources; Mines; Mining industry; Multiple objective analysis; Optimization models; Original Article; Pareto optimization; R&D; Raw materials; Research & development; Resource utilization; Rheological properties; Slag; Slurries; Solid wastes; Solids; Stainless steel; Structural Materials; Sustainable development; Microstructure characteristics; Multi-objective optimization model; Rheological characteristics; Solid waste cementitious materials; Orthogonal proportion test
• ISSN: 2083-3318; 1644-9665; 2083-3318
• DOI: 10.1007/s43452-025-01226-2

To accelerate the process of solid waste resource utilization, common industrial solid wastes were selected to prepare magnesium slag–steel slag-based composite cementitious materials synergistically. The cementitious material proportion scheme was designed, and the strength test was conducted to acquire the most advantageous proportion of the cementitious material. X-ray diffraction and scanning electron microscopy were utilized to analyze the hydration products and microstructure of the cementitious materials, further illuminating the strength formation process of the cementitious materials from a microscopic perspective. Based on the rheological experimental data of the filling slurry, a multi-objective optimization model with along-duct resistance and filling material cost as the objectives and the strength of all-solid waste cemented bodies at different ages as the constraints were established, and its optimal parameters were determined. The results demonstrated that the ideal proportion of magnesium slag–steel slag-based cementitious materials was 30% magnesium slag, 15% steel slag, 6% desulfurization gypsum, and 49% blast furnace slag. Including magnesium slag will help reduce the lack of hydration of steel slag and desulfurization gypsum in the initial stages, thus prolonging the hydration time and maintaining a high hydration reaction rate in the later stages. A comparative analysis revealed that the optimal proportion of the all-solid waste filling materials was a slurry concentration of 78% and a binder-to-aggregate ratio of 1:5 when using the multi-objective optimization model of the material based on the Pareto-dominated solution. The results can provide theoretical guidance for the proportion design of mine filling materials.