Performance and Sustainability of Lithium Slag as a Supplementary Cementitious Material: A Review

The growing demand for lithium usage expands lithium production, and the volume of waste generation continues to rise accordingly. The improper disposal of mining waste leads to serious environmental and health issues, underscoring the necessity of effective management and reuse of mining waste. Accordingly, researchers are evaluating the potential use of lithium waste, and as a result, the identification of Lithium slag (LS) as a promising supplementary cementitious material (SCM) is being actively pursued. The strategy is a response to dual challenges, the sustainable solution for lithium waste and substitution for Ordinary Portland Cement, which is contributing 8% of global CO₂ emissions during their production. This review evaluates LS-blended concrete performance, focusing on dosage, mix designs, strength, and durability based on previous studies. Substituting 20–30% of cement with LS enhances strength, lowers shrinkage and permeability, and refines microstructure through denser C–S–H and stronger ITZ. LS-modified concretes resist sulphate, acid, freeze-thaw, and thermal damage. Life cycle and techno-economic assessments show up to 30% reductions in embodied carbon and energy use, with potential cost savings due to LS's industrial waste status. LS also works well with recycled aggregates and alkali-activated systems. These findings confirm LS as a viable and sustainable SCM, supporting circular economic goals.