The unloading failure process in mining engineering scenarios is similar to the loading failure process at different loading rates indoor. To clarify the relationship between the mechanical properties of backfill and the loading rate, a particle flow code 2D-based numerical simulation was performed to establish the backfill model, and tests involving five loading rates were conducted. The following results were obtained: (1) the compressive strength of the backfill body increases linearly with the increase in the loading rate. The peak strain increases in an S-shaped manner, and the modulus of elasticity first increases and then decreases. (2) The evolution of cracks is similar to that of damage energy consumption, and a smaller rate means that the curve’s inflection point arrives earlier. (3) Tensile failure is the dominant failure mode. As the rate increases, the model destruction mode transforms from single to multiple failures, and the crack distribution becomes denser. (4) The backfill body exhibits a uniform destruction form at all loading rates. However, the difference in the loading rate leads to different energy consumption growth rates and total energy consumption.

This study systematically investigates the effects of shell ash (SA) content (0–10%) on early moisture evolution, pore structure, and hydration kinetics in cement paste using LF-NMR and NG-I-D hydration kinetic models. Key findings include the following: (1) Increased SA content significantly alters moisture phase distribution. Low contents (≤8%) consume free water through rapid CaO hydration, promoting C-S-H gel densification. However, 10% SA causes reduced moisture in 0.16–0.4 μm gel micropores (due to hindered ion diffusion) and abrupt increases in 0.63–2.5 μm pores. (2) Porosity first decreases then increases with SA content, reaching minimum values at 3–5% and 8%, respectively. The 10% content induces abnormal porosity growth from localized over-densification following polynomial fitting (R² = 0.966). (3) Krstulovic–Dabic model analysis reveals three consecutive hydration stages: nucleation–growth (NG), phase boundary reaction (I), and diffusion control (D). The NG stage shows the most intense reactions, while the D stage dominates (>60% contribution), with high model fitting accuracy (R² > 0.9). (4) SA delays nucleation/crystal growth, inducing needle-like crystals at 3% content. Mechanical properties exhibit quadratic relationships with SA content, achieving peak compressive strength (18.6% increase vs. control) at 5% SA. This research elucidates SA content thresholds governing hydration kinetics and microstructure evolution, providing theoretical support for low-carbon cementitious material design.

To address the inefficiency and data loss issues inherent in manual measurement, this study developed a full-time data extraction model for ultra-fine tailing slurry flocculation using Yolov8n. The performance of five flocculants—cationic polyacrylamide (YPAM), non-ionic polyacrylamide (FPAM), polyaluminum chloride (PAC), polymeric ferric sulfate (PFS), and a commercially used flocculant (KY)—was evaluated based on type, dosage, and pH. The model’s reliability was validated through slurry grayscale and clarification height analysis. Results indicate that the model enables automated data collection under varying lighting and viewing angles. YPAM was identified as the optimal flocculant across different pH conditions, improving the selection efficiency by 83% compared to manual methods.

To achieve the resource utilization of waste tires and improve the mechanical performance of cemented tailings backfill, rubber–cemented tailings backfill (R-CTB) specimens were prepared with four rubber particle sizes (20-, 40-, 60-, and 80-mesh) and four contents (2%, 4%, 6%, and 8%). A 0% rubber control group was introduced to address the lack of quantitative comparison. Uniaxial compression, digital image correlation (DIC), and scanning electron microscopy (SEM) were used to study mechanical behavior, energy evolution, and microstructural characteristics at 7 and 28 days. Results indicate that strength and elastic modulus first increase then decrease with particle size and decrease with content rise. Compared with the control group, R-CTB shows lower strength but significantly higher ductility and energy dissipation. Finer particles cause strain localization; higher content and finer size increase pores and weaken interfaces. Rubber incorporation transforms failure from brittle to ductile, providing a basis for engineering application.