Analysis of Factors Influencing the Flow Characteristics of Paste Backfill in Pipeline Transportation

Abstract

The continuous accumulation of tailings in tailings reservoirs not only causes environmental pollution but may also cause geological disasters. The paste-filling mining method is an effective way to address the accumulation of tailings, and it is necessary to study the flow characteristics of the pipeline transportation process—a core process of this method. However, limited by factors such as test conditions, equipment, and cost, the research in this field mainly focuses on the flow performance of conveying materials and the influence of single conveying conditions on the resistance of filling pipelines. The pipeline transportation of paste is a systematic project, and its pipeline transportation characteristics are not only determined by the characteristics of the slurry itself but also related to the geometric characteristics of the pipeline. In this study, an orthogonal test and numerical simulation were used to study the influence of five parameters—i.e., the filling gradient, the curvature radius of the elbow, the inner diameter of the pipeline, the paste flow rate, and the paste concentration—on pipeline transportation characteristics, and they were sorted according to their levels of influence. The results show that, during the pipeline transportation process, the slurry concentration has the greatest influence on the resistance loss and the maximum wall shear stress of the pipeline, and the slurry flow rate has the greatest influence on the maximum flow rate at the elbow. The numerical simulation results were compared and analyzed using rheological theory. The maximum difference rate was 11%, and the average difference rate was 6%. Numerical simulation results indicate that the pipe wall near the outer diameter side of the inlet section and the center of the elbow section wears easily during the paste-conveying process. The results enrich the theory of paste pipeline transportation, improve the understanding of the influence of various parameters on paste transportation characteristics, and provide a reference for paste pipeline design.