This study investigates the use of iron ore tailings (IOTs) as recycled aggregates in segmental blocks, focusing on technical performance, CO₂ emissions, and embodied energy using the cradle-to-gate approach. IOTs replaced fine aggregates in concrete at 25%, 50%, and 75% by volume, achieving compressive strengths of 16.23 MPa, 10.02 MPa, and 3.93 MPa, respectively. Raw material production accounted for 98% of CO₂ emissions and 86% of embodied energy. Producing blocks at mining sites offered limited environmental benefits due to longer transport distances. Despite this, the results showed a 6% reduction in CO₂ emissions and a 35% improvement in mechanical–environmental performance (CO₂ emissions weighted by compressive strength) compared to traditional concrete. These findings underscore the potential of IOT-based concrete for segmental block production.

The transition toward a circular economy in the mining sector has increased the need for sustainable strategies capable of recovering value from tailings generated during mining activities and supporting the safe closure of tailings dams. The present study evaluates the environmental performance of reverse mining as a circular economy strategy by comparing two iron ore tailings valorization pathways: mineral reprocessing for iron recovery and reuse as aggregates in cementitious composites. A Life Cycle Assessment (LCA), conducted in accordance with ISO 14040 and ISO 14044 standards, was applied using OpenLCA software and primary operational data collected from a full-scale tailings dam decommissioning project in Minas Gerais, Brazil. Environmental impacts were assessed in ten impact categories using the ReCiPe Midpoint methodology, with emphasis on Global Warming Potential (GWP). Reverse-mined tailings presented a GWP of 1.91 kg CO₂ eq/t, substantially lower than conventionally mined iron ore (6.80 kg CO₂ eq/t) and comparable to natural sand (1.88 kg CO₂ eq/t). Mineral reprocessing reduced the GWP associated with iron ore production by approximately 50%, while the reuse of tailings as construction aggregates proved environmentally competitive under suitable transport conditions. These findings demonstrate that reverse mining can support sustainable tailings dam closure by reducing environmental impacts, recovering secondary resources, and advancing circular economy practices in the mining sector through a practical decision-support framework based on primary industrial data.

Iron ore tailings (IOTs) are generated in massive volumes by mining, posing environmental risks through land occupation, dam failures, and heavy metal contamination, while construction faces growing pressure toward sustainable materials. This systematic review evaluates IOT valorization in construction materials, focusing on composition and water absorption performance. A structured search in Scopus^® identified experimental studies (2015–2025, English), excluding reviews, simulations, and non-IOT studies. Data were synthesized narratively by matrix type. The 24 studies reporting water absorption were also assessed for methodological quality using a bespoke six-criterion checklist, as no validated risk-of-bias tool exists for such experiments. Of 145 documents screened, 74 met the inclusion criteria. IOT content ranged from below 10 wt% to full substitution across cement-based, ceramic, geopolymer, alkali-activated, and polymer matrices. Water absorption varied accordingly: cement-based blocks with full substitution achieved 4.6%, bricks reached 18.0%, geopolymer/AAC composites ranged 13.0–21.0%, polymers achieved the lowest values (0.1–0.4%), and ceramics varied broadly (0.4–49.2%). Quality assessment classified 54.2% of studies as low risk and 45.8% as moderate risk, and inconsistent variability reporting was the main limitation. Performance depended on matrix type, IOT content, and processing, supporting circular IOT reuse in construction. This review received CAPES funding and was not registered.