Abstract
The waste residues produced by metallurgical industry have caused great harm to the environment. Three kinds of residues, lithium slag (LS), copper slag (CS), and desulfurized gypsum (DG) were employed as partial cement replacements to develop an eco-friendly cementitious composite. It was found that the essential particles were generated using wet ball milling 10.0 wt. % LS and 20.0 wt. % CS, upon activation with 6.0 wt. % desulfurization DG, the hydration quality of the slurry was markedly enhanced as an additive to substitute the equivalent percentage of ordinary Portland cement (OPC). The ‘low-alkali activation and optimal ratio’ synergistic approach effectively enhances the reactivity of the LS-CS composites. Meanwhile, the nucleation effect of LS and the filling effect of CS, contributes to the microstructural refinement. The result showed that the optimized specimen attained 77.78 and 95.76% of the control (C0)’s compressive strength at 3 and 28 days, respectively. The hydration was comprehensively characterized by quantitative X-ray diffraction (QXRD), SEM and FTIR spectroscopy, and the surface fractal was analyzed by MIP data. Furthermore, the test data indicated that LS exhibited substantial calcium hydroxide (CH) consumption while concurrently activating CS hydration, resulting in enhanced C- (A, F)-S-H phase formation. Overall, this investigation presents an effective approach for the thorough utilization of LS and CS. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-026-38577-6.