Tailings are solid waste generated during mining and mineral processing. Their tremendous accumulation not only encroaches on arable land but also pollutes the environment. Currently, tailings are considered a viable alternative to natural fine aggregates in concrete because of their suitable physicochemical properties. However, existing studies remain highly fragmented and often report inconsistent conclusions owing to the considerable variability in tailings mineralogy, particle morphology, and physicochemical characteristics. To date, a comprehensive synthesis linking these intrinsic properties to the fresh, mechanical, durable, microstructural, environmental, and economic performance of tailings concrete remains lacking. Therefore, this review provides a systematic and critical assessment of tailings as aggregate in concrete and proposes an integrated framework connecting tailings characteristics, microstructural evolution, engineering performance, and sustainability outcomes. It systematically examines the physico-mechanical properties, durability, microstructure, hydration characteristics, environmental impact, and economic benefits of the resulting tailings concrete. The results showed that although tailings varied considerably in particle size, chemical composition, and mineralogy, they typically exhibited a rough surface texture and high water absorption. Furthermore, partial substitution of fine aggregates with tailings was found to improve the physical–mechanical properties and durability. However, to prevent performance decline, the substitution ratio should not exceed 50%. These benefits originated primarily from the filling effect and optimized particle packing, which increased matrix density. Microstructural analyses indicated that moderate tailings contents refined the pore structure, strengthened the interfacial transition zone (ITZ), and promoted hydration. In contrast, excessive substitution ratios weakened bonding and increased porosity. From an environmental perspective, the use of tailings generally reduced carbon emissions (by up to ~28%) and production costs (by up to ~50%) by lowering natural resource consumption and enabling large-scale waste valorization. Overall, tailings represent a sustainable aggregate alternative, provided that substitution levels are carefully controlled to balance workability, performance, and durability.

The stability of tailings dams is governed predominantly by the physical properties and geotechnical behavior of their primary construction material—tailings. Consequently, a systematic understanding of these characteristics is of great significance for the rational design and long-term stable operation of tailings dams. This review focuses on the physical properties and geotechnical behavior observed in different types of tailings. In terms of physical properties, the particle size distribution exhibits a pronounced hydraulic classification characteristic within the impoundment, consisting predominantly of silt-sized particles and displaying an overall trend toward finer gradation. The mineralogical and chemical composition is dominated by quartz, hematite, and silicates. However, significant spatial variability exists both between different tailings types and across distinct zones within the same tailings pond. Regarding geotechnical behavior, the permeability of tailings is governed by a fines content threshold: below this threshold, permeability decreases with increasing fines content, while beyond it, the permeability stabilizes. When studying consolidation and compression behavior using slurry specimens, the compression curves exhibit nonlinear characteristics, primarily described by the modified Gibson theory. The shear behavior of tailings is significantly influenced by confining pressure, drainage conditions, anisotropy and stress paths. The presence of transitional behavior leads to the critical state line determined based on a single sampling method erroneously assessing the dilation/cosntraction characteristics of in situ tailings, thereby affecting the assessment of liquefaction risk. Future research should focus on the seepage, consolidation and shear properties of clayey fine-grained tailings and unsaturated tailings, and aim to elucidate the key controlling factors of transitional behavior to enhance the reliability of tailings dam stability assessments.