High-pressure atomization dust reduction with amphoteric/anionic compound wetting agent

To resolve the problem of high concentration dust pollution during the production of fully-mechanized coal mining face, based on the analysis of the dust reduction behavior of amphoteric/anionic compound wetting agent (AAC) and high-pressure atomization, the dodecyl dimethyl betaine (BS-12) and the sodium sec-alkyl sulfonate (SAS) were compounding studied by orthogonal experiment. The optimum wetting mass fraction of AAC was selected by dust settling experiment and solution surface tension test, the wetting ability of BS-12, SAS, and AAC was compared by immersion aspiration test. Combined with the on-site dust reduction practice, the dust reduction effect of mine water, BS-12, SAS and AAC with the same mass fraction was compared under the high-pressure atomization pressure of 8 MPa and the wind speed of 1.5 m/s in the fully-mechanized coal mining face. Results showed that the optimum mass fraction ratio of BS-12 and SAS was 0.30%∶0.20%, when the mass fraction of AAC was 0.20%, the dust settling time and the solution surface tension tended to be the minimum value. At the early stage of soaking, the coal bodies in AAC, SAS, BS-12 solution and mine water were in a fast absorption state, the soaking time was 4 h, the absorption rate of coal bodies in AAC solution increased by 87.83%, 24.14%, and 16.76% compared with that in mine water, BS-12, and SAS solution respectively; at the later stage of soaking, the absorption rate of coal bodies in each solution were gradually stabilized. The dust concentration in fully-mechanized coal mining face increases and then decreases, and the highest point of dust concentration is located near 10 m on the downwind side of the shearer. After AAC high-pressure atomization dust reduction, the average dust reduction efficiency of total dust and respirable dust was 91.63% and 91.59% respectively, and the dust reduction effect of AAC high-pressure atomization was significantly higher than that of mine water, BS-12 and SAS. © 2023 Zhejiang University. All rights reserved.