Preparation and dust suppression performance of biological dust suppressant based on bacillus mucilaginosus induced mineralization synergized with straw fiber

Coal mine dust control is a critical link in ensuring production safety and occupational health. Currently, it mainly relies on chemical dust suppressants to improve the dust reduction efficiency of water-based methods, but problems such as poor environmental compatibility and potential pollution remain. To address these issues, this study proposes a novel bio-based dust suppressant, BM-SFDS (Biological Mineralization & Straw Formulation Dust Suppressant), which synergistically combines microbial-induced mineralization and agricultural waste (straw) to achieve efficient and green dust control. Response surface methodology was used to optimize the fermentation conditions for enzyme production by Bacillus mucilaginosus, and the optimal conditions were determined as temperature 32.5 ℃, pH 8.15, inoculation ratio 10.8%, and shaking speed 221 r/min. Under these conditions, the carbonic anhydrase activity reached 0.0284 U. Furthermore, orthogonal experiments determined the optimal component ratio of Component A of the dust suppressant: straw 15.0 g/L, starch 8.0 g/L, corn steep liquor 10.0 g/L, and guar gum 0.8 g/L. Component B is calcium lactate solution. The two components are mixed on-site for immediate use. Contact angle measurements showed that a 120 mg/L BM-SFDS solution reduced the contact angle of the coal dust surface from 68.47° (with deionized water) to 24.83°. Compared to 500 mg/L sodium dodecylbenzenesulfonate (SDBS) (42.36°), the contact angle was further reduced by 17.53°. Wind tunnel experiments showed that under a strong wind speed of 12 m/s, the wind erosion rate of the BM-SFDS consolidated layer was only 0.73%, significantly better than SDBS (4.10%) and water spraying (71.39%). In terms of wettability and wind erosion resistance, the concentration of BM-SFDS required to achieve the best comprehensive performance is only about one-quarter of that of SDBS. SEM and EDS analyses revealed that BM-SFDS generates CaCO₃ crystals through microbial mineralization, which synergistically constructs a dense organic-inorganic hybrid consolidated layer with the straw fiber-polysaccharide network, thereby achieving efficient dust fixation. This dust suppressant has broad application prospects in scenarios such as coal mining, transportation, and open stockpiles.