A hydraulic gradient model of paste-like crude tailings backfill slurry transported by a pipeline system

A hydraulic gradient model, which can be used to compute the hydraulic gradient of paste-like crude tailings backfill slurry (PTBS) transported by a pipeline system in a mine, was constructed based on rheological model derivation, numerical simulation, and regression analysis. It was proven, by a Bingham rheological model analysis of the PTBS, that the hydraulic gradient of the PTBS is inversely proportional to the pipe diameter and proportional to the average flow velocity. It was also clarified that the hydraulic gradient value depends primarily on the rheological parameters of the PTBS if the pipe diameter and flow velocity are adjustable. Consequently, rheological parameters of the PTBS in different slurry mass fractions were obtained through 3D simulation with FLUENT. The slurry pipeline transportation process and the relationship between rheological parameters and slurry mass fraction were regressed by MATLAB mathematical software. Finally, a hydraulic gradient model describing a variation rule of the hydraulic gradient of the PTBS to pipe diameter, flow velocity, and slurry mass fraction was constructed. A comparable study between the calculation result and site date indicates that the model has enough accuracy to satisfy the requirement of backfill system design with an average deviation of 8 %.