Geomechanical zoning of aged tailings at the urup tailings storage facility as a basis for differentiated processing and backfilling

This paper proposes an integrated approach to developing aged tailings at the Urup tailings storage facility through combined geometallurgical and geomechanical zoning. Spatial heterogeneity in metal grades, particle-size distribution, filtration behavior, and process response requires domain-based processing. The approach links Cu, Zn, and Au recoverability with residue suitability for thickening, dewatering, and use in cemented backfill systems after metal recovery. Introduction. Growing tailings volumes and stricter environmental requirements demand a shift from passive storage to integrated processing and reuse, especially for highly heterogeneous tailings such as those at Urup. The aim of the work. The aim of the study was to identify the patterns of spatial variability in the geometallurgical and geomechanical characteristics of aged tailings at the Urup tailings storage facility and, on this basis, to develop zoning principles that support differentiated recovery of valuable components and justify the use of de-metallized residue in backfill technologies. Materials and methods. Aged tailings from the Urup facility were studied using zonal sampling, chemical and fire-assay analysis, granulometry, physical-mechanical testing, and hydrocyclone, gravity, and flotation experiments after controlled regrinding. Research results. The southern sector shows clear vertical geochemical differentiation, with higher Cu, Zn, and Fe contents below the water horizon and increased oxidation above it. The northern dry sector forms a gold-bearing domain. Two tailings types were distinguished: fine-grained metal-bearing and coarse sandy varieties. The best technological results were achieved by gravity concentration and flotation after controlled regrinding. Discussion of research. The study converts tailings heterogeneity into an engineering decision framework. Geometallurgical criteria define zones for Cu, Zn, and Au recovery, while geomechanical criteria identify residue suitable for backfill. Coarse sandy varieties are shown to retain gold potential and favorable thickening and dewatering properties. Conclusion. Aged tailings at the Urup facility are a spatially differentiated technogenic resource. Combined geometallurgical and geomechanical zoning defines metal-recovery domains, rational preparation of fine-grained tailings, and sandy material suitable for backfill. Resume. The efficiency of aged tailings development depends on delineating technologically homogeneous domains rather than using averaged grades, enabling integrated metal recovery, environmental risk reduction, and reuse in underground backfill. Practical application and future research. The results support a differentiated processing flowsheet including selective excavation, separate stockpiling, preliminary gravity gold recovery, limited regrinding of fine-grained tailings before flotation, and use of the de-metallized sandy fraction in backfill mixtures. Further research should include pilot-scale validation, 3D domain refinement, and development of optimized backfill formulations

Heavy metals · Tailings · Tailings dam · Zoning · Metal Extraction and Bioleaching · Mine drainage and remediation techniques · Tailings Management and Properties