Study on the performance of a composite dust suppressant in open-pit mines

Abstract

Currently available chemical dust suppressants (DSs) still have only one single function, are expensive, and generate secondary pollution and other problems. In this study, xanthan gum (XG), rhamnolipid (RL), glycerol (GL) and magnesium chloride (MgCl₂) were combined to develop a composite DS that is highly efficient and suitable for transportation roads in open-pit mines. This study used response surface testing to optimize the proportions of the reagents in the DS, conducted experiments such as simulated dust reduction to study its performance, and analyzed its economic and environmental benefits. The optimal ratios were found to be 0.15%, 0.15%, 3.2% and 2.8% for XG, RL, GL and MgCl₂, respectively. The dust samples’ viscosity, pH, and evaporation resistance could reach 81.98 mPa s, 6.48 and 5.20%, respectively. Compared to water, DS-treated dust samples were 5% more hygroscopic, 30% more resistant to wind erosion, and twice as resistant to compression. The dust reduction efficiency (DRE) for total and respiratory dust increased to 91.38% and 81.22%, respectively. Scanning electron microscope (SEM) experiments showed that the addition of the DS allowed small particles to gradually coalesce and adsorb onto the surface of larger particles, which had a good cohesive solidification effect and improved the dust suppression effect. The results of the benefit analysis showed that the DS could save CNY 6,390 per month and was environmentally friendly.