Hydration behavior, microstructural characteristics, and kinetic analysis of cemented tailings backfill under temperature effect

The hydration behavior of cemented tailings backfill (CTB) is critical to understanding its mechanical performance and microstructural evolution. This study proposes a modified hydration kinetics model that accounts for the dilution, dissolution, and nucleation effects of tailings, with variable growth rates. The model was validated through isothermal calorimetry and closely matched experimental data. Results show that elevated curing temperatures accelerate hydration reactions, with both the maximum growth rate and critical nucleus length exhibiting S -shaped trends. The degree of hydration peaks at 40 ℃, beyond which further increases in temperature reduce hydration efficiency due to early surface densification and hindered ion transport. Kinetic parameters were found to exponentially shorten hydration stage durations, while cumulative heat release increases and then declines with temperature. These findings improve the understanding of temperature-dependent hydration mechanisms and provide theoretical support for optimizing CTB mix design and curing strategies in deep mining environments, where thermal conditions critically affect early strength development and backfilling efficiency.