Study on the microscopic mechanism and optimization of dust suppression by compounding biological surfactants

Abstract

In order to solve the problem of reducing the surface tension of pure water used in some spray dust reduction equipment, this study analyzed the action mechanism of the green biodegradable dust suppressant on coal dust from a microscopic point of view. Using orthogonal experiment design and response surface analysis method, the surface tension change of the green biodegradable composite dust suppressant and its influence on the wettability of coal dust is studied, several biological surfactants are added to water in nine groups in different proportions to prepare dust suppressants with the same total concentration. Through nine sets of sedimentation experiments with different configuration ratios, it is concluded that each set of compound dust suppressants can improve the wetting speed of coal dust to varying degrees. In the infrared spectroscopy experiment, we analyze the microscopic interaction mechanism of coal dust, compare the wettability of anthracite coal samples before and after treatment with the same quality dust suppressant through the change of functional groups. The internal mechanism of the biodegradable dust suppressant is explained from a two-dimensional curve, the low hydroxyl transmittance means high content, which effectively increases the hydrophilic groups on the surface of coal dust, thereby accelerating the wetting speed. The surface tension experiment showed that the use of compound reagents had a good synergistic effect. The lowest surface tension of the biodegradable dust suppressant is 28.515 mN/m in nine groups. Through response surface analysis method, the study finds the optimal value of the wetting speed of the dust suppressant, obtains the best ratio of each reagent in this new dust suppressant by using Design Expert 11.0. The optimal ratio is calculated as: 0.129 ml rhamnolipid, 0.044 ml lactone sophorolipid and 0.029 g surfactin per 100 ml of dust suppressant, the shortest wetting time is 31.777 s. • A biological compound dust suppressant with excellent wetting effect was prepared. • The hydrophilic functional groups on the surface of coal dust was changed by the composite dust suppressant. • The lowest surface tension of the biodegradable dust suppressant is 28.515 mN/m. • The optimal ratio of the dust suppressant is rhamnolipid 12.9%, lactone sophorolipid 4.4%, Surfactin 2.9%.