Study on wettability of water stemming for blasting dust adjusted by surfactants and inorganic salts

Abstract

Water stemming is an efficient method of removing blasting dust by wetting. There is still a lack of methods for rapid optimization of water stemming components with high wettability. Herein, blasting dust was collected from a tunnel in Chongqing (China) to investigate its removal performance by different water stemmings. The two most important components of blasting dust were SiO₂ and CaCO₃ by characterization analysis. Notably, hydrophilic blasting dust has significantly more SiO₂ than hydrophobic blasting dust. The density functional theory calculation predicted the wettability of water stemming containing sucrose fatty acid ester (SE) higher than that of water stemming containing other surfactants. Moreover, the water contact angle and surface tension experiments determined the addition of inorganic salts to the water stemming containing SE could increase its wettability, with the addition of Al³⁺ giving the best performance. The sink test and water retention experiment further prove that our synthesized water stemming has a good wetting ability on both hydrophobic and hydrophilic blasting dust. The findings of this study advance the development of reliable methods for optimizing water stemming with high wettability for removing the blasting dust.

Keywords: blasting dust; inorganic salts; surfactants; water stemming; wettability.

Figure 1.

(a) FESEM Images of hydrophilic blasting dust; EDX elemental mapping of hydrophilic blasting dust (b) C, (c) O, (d) Al, (e) Si and (f) Ca; (g) FESEM Images of hydrophobic blasting dust; EDX elemental mapping of hydrophobic blasting dust (h) C, (i) O, (j) Al, (k) Si and (l) Ca.

Figure 2.

XPS spectra of hydrophilic and hydrophobic blasting dust (a) Ca 2p, (b) Si 2p and (c) O 1s.

Figure 3.

Adsorption configurations and adsorption energies (Eads) of CTAB, SDS and SE on (a) SiO₂ and (b) CaCO₃ surfaces using DFT methodology.

Figure 4.

The contact angles of the water stemming containing DI water, SE, SDS and CTAB with (a) hydrophilic and (b) hydrophobic blasting dust.

Figure 5.

The surface tension of water stemming containing SE and (a) Al³⁺, (b) Ca²⁺ and (c) Na⁺ ions at different concentrations.

Figure 6.

(a) The CMC of SE containing 10 mM Al³⁺, Ca²⁺ and Na⁺; (b) Plots of the logarithm of the CMC values for SE containing different concentrations of salts.

Figure 7.

(a) The contact angle of hydrophilic and hydrophobic blasting dust with water stemming containing 10 mM Al³⁺ and 0.25 mM SE. (b) The evaporation rate of water and water stemming containing 10 mM Al³⁺ and 0.25 mM SE on hydrophilic and hydrophobic blasting dust. (c) The sink time of hydrophilic and hydrophobic blasting dust in water and water stemming containing 10 mM Al³⁺ and 0.25 mM SE.