Porous media grouting diffusion mechanism based on tailings slurry phase change characteristics

Area of Science:

• Geotechnical Engineering
• Materials Science

Background:

• Tailings slurry diffusion is crucial for long-duration grouting.
• Understanding slurry rheology and phase transition is key to predicting its behavior in porous media.

Purpose of the Study:

• To investigate the diffusion mechanism of tailings slurry in porous media.
• To develop and validate a time-dependent Bingham rheological model for tailings slurry.

Main Methods:

• Laboratory experiments to measure slurry rheological properties at varying temperatures and water-cement ratios.
• Development of a phase transition constitutive equation.
• Derivation of a diffusion equation for tailings slurry considering phase transition and porous media characteristics.
• Grouting simulation experiments for validation.

Main Results:

• The time-dependent Bingham model accurately describes the shear stress-shear rate relationship (R² > 0.95).
• Yield stress and viscosity increase with temperature and decrease with water-cement ratio, following a quadratic function over time.
• Water-cement ratio significantly impacts rheological properties more than temperature.
• The model's predictions show less than 10% error compared to simulation data.

Conclusions:

• The developed time-dependent Bingham model effectively captures tailings slurry diffusion in porous media.
• The model provides accurate predictions for grouting pressure, revealing a distinct two-stage growth trend.
• This research enhances understanding and prediction of grouting processes involving tailings slurry.