Determining the pressure drop of cemented Gobi sand and tailings paste backfill in a pipe flow

Abstract

The pressure drop in pipes is a crucial parameter for the design of mine backfill. The friction factor correlations used to predict the pressure drop have not been validated for mine backfill. Therefore, this study presents a flow loop test to estimate the pressure drop based on a practical engineering case of cemented Gobi sand and tailings paste backfill (CGTPB). We employed two friction factor models for the pressure drop calculations in order to compare and validate our proposed test. Moreover, the effects of the CGTPB mixing components (solid mass concentration, binder content, and Gobi sand/tailings ratio) on pressure drop were investigated. Results demonstrate that the Swamee–Aggarwal model is able to effectively predict the pressure drop for Bingham plastic fluids that exhibit a laminar flow within the pipe. Furthermore, the pressure drop increases with concentration and binder content. The gel hydration product provides a lubricating effect that significantly reduces the pressure drop at a greater rate compared to the non-cementitious slurry. In addition, higher combined aggregate packing and slurry bulk densities will increase the pressure drop. The findings from our study contribute strongly to the mine backfill practice.