Improving dust resistance of mine tailings using green biopolymer

Abstract

The application of biopolymers as eco-friendly stabilisers for strengthening soils has received increasing attention in recent years. This paper presents an experimental and numerical investigation of using xanthan gum, a green biopolymer, to stabilise mine tailings (MTs) for dust control. Impact tests that simulate the saltation process during wind erosion were carried out to evaluate the effect of xanthan gum on the impacting resistance of MTs, which is directly related to dust resistance. The impact test results show that the weight loss due to grain impacts is significantly reduced for biopolymer-treated MTs compared to that for untreated MTs, with more biopolymer leading to greater reduction. The improved dust resistance of MTs after biopolymer treatment may be attributed to the protective biopolymer coating formed at the surface of treated MTs, which imparts the MTs with a dense structure and enhanced cohesion and therefore improves the impacting resistance. Numerical simulation using the discrete element method was performed to explore the underlying mechanisms of how the biopolymer increases the dust resistance of MTs. The simulation results show that the bonding strength between MT particles increases linearly with biopolymer concentration; more biopolymer induces stronger interparticle bonding and therefore increases the impacting and cracking resistance of MTs.