Experimental investigation of the properties of dust suppressants after magnetic-field treatment and mechanism exploration

Abstract

To understand the properties of dust suppressants after magnetic-field (MF) treatment and to explore the MF mechanism, dust suppressants (nonionic and anionic surfactants) with different solute volume fractions and MF exposure time were investigated. The effect of the MF on the dust suppressants was characterized by two property changes, namely, the wetting ability and the permeability. During the experiments, parameters such as exposure time to the MF, the surface tension, the contact angle, and the penetrating speed were measured. Nonionic and anionic surfactant solutions responded to MF treatment. The most responsive surfactant was 0.05 vol% Tween-80, which showed a maximal improvement of 11.8 mN/m surface tension and 16.3° in contact angle. Its penetrating speed was also higher than that previously. MF had an obvious influence on nonionic surfactant solutions, especially at concentrations below the critical micelle concentration, and a relatively weak effect on anionic surfactant solutions. This may be because the two surfactant types ionized differently in solution. A relationship existed between concentration and property improvement. A higher surfactant solution surface tension resulted in a greater surface tension improvement during MF treatment, and similar results were observed for the contact angle. The regularity of the effect was difficult to describe precisely and quantitatively. To explain the effect of an external MF on dust suppressant solutions and for practical applications, a mechanism was proposed from a molecular and hydrogen-bond perspective. The critical point was the dynamic process of the formation and fracture of hydrogen bonds in solutions, which was affected by the MF and by surfactant ionization. This research is of important guiding significance for the development of magnetized dust suppressants.