Life cycle assessment of delithiated beta spodumene as a supplementary cementitious material in concrete compared to fly ash

Delithiated beta spodumene (DBS), a byproduct of the lithium industry, presents a promising solution to reduce the environmental impacts of concrete through its use as a supplementary cementitious material (SCM). This study conducted the first comprehensive cradle-to-gate life cycle assessment (LCA) comparing DBS with fly ash (FA) and ordinary Portland cement (OPC), accounting for upstream allocation and processing. Concrete mixes with 20% DBS replacement were evaluated against FA concrete mixes from the literature that were within the same nominal N32 strength grade. Scenario and uncertainty analyses were conducted to assess the effects of data variability and supply chain conditions on environmental impacts. Results show that DBS achieves up to ∼75% lower global warming potential (GWP) than FA and over ∼95% lower than OPC. Beyond GWP, DBS also demonstrates notable reductions in acidification and photochemical oxidation, although its abiotic depletion is higher than that of FA due to upstream lithium extraction. Concrete with 60% replacement by DBS reduces GWP by ∼40%. Break-even transport analysis indicates that DBS maintains environmental benefits relative to OPC up to ∼15,300 km by truck and 47,400 km by ship. Monte Carlo simulations quantify uncertainty and indicate a 99% probability that DBS outperforms FA at the SCM level with respect to GWP and acidification potential. This study demonstrates the potential of DBS as a viable low-carbon SCM. In addition to providing the first life cycle inventory for DBS, the proposed framework enables robust environmental assessment of this emerging SCM by integrating allocation, transportation sensitivity, regional variability and probabilistic uncertainty into a single comparative methodology, which can also serve as a benchmark for future studies evaluating emerging SCMs. These methodological components provide a transferable foundation for future assessments of emerging SCMs, although the inventory data and regional assumptions must be adapted to the specific material and geographical context.