377 as an enabler for broader circular economy and low-carbon objectives. When filtered tailings are placed in a controlled, trafficable configuration, they become more accessible for future reprocessing, re-use in construction and more efficient closure solutions. In parallel, high rates of water recovery and the potential to integrate heat and renewable energy systems can improve the overall resource efficiency of the mine-to-mill chain. 5.1 Water and energy recovery opportunities Filtered tailings operations commonly return a large fraction of process water directly from thickeners and filters back to the plant. In practical terms, the value proposition of dry stacking lies in converting tailings dewatering from a disposal step into a measurable watermanagement function, where recovery efficiency, residual moisture and long-term free-water storage become decision variables rather than secondary outcomes. Compared with conventional slurry ponds, this reduces the need for make-up water, lowers pumping distances and helps decouple process reliability from local hydrological variability (Sahu et al., 2020). In cold and northern climates, where water management is complicated by snowmelt peaks, ice cover and changing precipitation regimes, high water-recovery efficiencies can significantly reduce the demand on freshwater sources and receiving water bodies. In addition to water, dewatering circuits and warm tailings streams carry sensible heat that could in principle be recovered. Heat exchangers or heat-pump systems coupled to warm process water or tailings filtrate may support low-temperature district heating, mine ventilation air heating or other on-site uses, especially in regions with long heating seasons. Although practical implementations remain limited, the combination of high water-recovery rates and potential heat utilization positions dry stacking as part of a broader strategy to optimize both water and energy use along the mine-to-mill pathway. 5.2 Tailings as a resource in circular economy Circular economy strategies increasingly emphasize the valorization of mining wastes as secondary resources. Controlled, relatively homogeneous dry stacks can facilitate future access to tailings volumes, reducing the cost and complexity of re-mining or reprocessing compared with submerged or unconsolidated slurry ponds. Tailings have been investigated as sources of critical and battery minerals, as feedstock for geopolymers and ceramics, and as constituents in construction materials such as masonry units, road bases and backfill (Lottermoser, 2010; Kossoff et al., 2014). From a circularity perspective, dry stacking offers several advantages. First, higher water-recovery and improved geotechnical stability reduce the environmental liabilities associated with long-term pond management, which can otherwise limit the feasibility of future reprocessing (UNEP, 2019). Second, the ability to build engineered, accessible landforms supports staged reclamation, integration of re-use projects and potential co-location with other industrial activities. However, moving from conceptual potential to large-scale implementation requires addressing regulatory acceptance, material qualification standards and economic trade-
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