Experimental Study on the Sedimentation Characteristics of Classified Tailings Underwater

Understanding the short-term underwater settling behavior of classified tailings is important for interpreting deposit formation in ponded areas. One-dimensional settling-column tests were conducted for 36 h to examine how fine-particle content (<0.075 mm) and nominal slurry mass concentration were associated with soil-water interface evolution, visually defined settling phases, and cumulative interface displacement. The observations showed an early rapid-settling period, a post-interface settling/compression period, and a later low-rate compression period. After 36 h, the columns displayed a clear-water zone above a visually layered deposit. Across the six treatment means, 36 h cumulative settlement decreased as fine-particle content or nominal mass concentration increased. These are time-specific descriptive trends, not evidence of lower ultimate settlement: equilibrium was not demonstrated, only duplicate runs were performed, and the archived concentration-series records do not contain the run-specific initial volume, height, or component masses needed to isolate a concentration effect. No rheological, pore-pressure, microstructural, strength, or water-content measurements were made. The results therefore describe short-term behavior in a static laboratory column and should not be directly extrapolated to field-scale tailings facilities.