CFD Simulation of Pipeline Transport Properties of Mine Tailings Three-Phase Foam Slurry Backfill

Xin Chen,Qiusong Chen,Xiuzhi Shi,Jian Zhou,Yonggang Gou

doi:10.3390/min7080149

Abstract

A three-dimensional backfill pipeline transport model is developed using the computational fluid dynamics (CFD) technique, which is applied to study the pipeline transport properties of three-phase foam slurry backfill (TFSB). Based on rheological property tests and CFD simulations, the foam phase, pressure, and velocity in the pipeline system are investigated using the CFD mixture method for different bubble volume fractions and bubble diameters. The simulation results indicate that TFSB can maintain a steady state during pipeline transport, experience a markedly reduced pipeline transport resistance, and exhibit better liquidity than conventional cement slurry. Furthermore, as the bubble volume fraction increases, the resistance of the pipeline decreases and the fluidity improves. By contrast, the bubble diameter has little effect on the transport properties of TFSB. The combined results of CFD simulations, slump tests, and strength tests indicate that, when the bubble volume fraction is 15–20 vol %, TFSB can satisfy the necessary strength requirements and exhibit self-flowing transport. The CFD technique provides an intuitive and accurate basis for pipeline transport research and has the potential for wider application in studies of mine backfill.

Highlights

Paste backfill technology represents an important direction for the development of mine backfill techniques [1,2,3,4,5]
Foam is a porous membrane dispersion system formed of a mixture of liquid and gas, in which the liquid is in a continuous phase and the gas is in a dispersed phase, and a standard foam flow is the necessary condition and foundation for foam slurry preparation
During the process of preparing three-phase foam slurry backfill (TFSB), the quantity of the standard foam is measured based on During the process of preparing TFSB, the quantity of the standard foam is measured based on the bubble volume fraction, which indicates the volume fraction of the standard foam

Summary

Introduction

Paste backfill technology represents an important direction for the development of mine backfill techniques [1,2,3,4,5]. Backfill pipeline systems have been established in many mines as transportation systems to transport backfill material from the surface to the goaf [9]. These backfill pipelines have become much longer and deeper than before, and it has become difficult to achieve self-flowing transport of conventional cement slurry because of its poor fluidity. Paste pumping technology can solve this problem, the purchase and maintenance of the necessary backfill pump equipment represents an enormous expenditure for a mine. An increasing amount of attention has been paid to improve the transport properties of paste slurry while satisfying the transportation and strength requirements of the backfill [10]

Methods

Results

Conclusion