Abstract: In order to prevent and control issues such as pneumoconiosis and air pollution caused by coal dust,following the principle of " controlling dust with waste" ,a molasses-based foam dust suppressant was prepared using molasses,a by-product of the sugar industry. The molasses-based foam dust suppressant (TM-CMCS / RC) was obtained through mechanical stirring and foaming after adding carboxymethyl chitosan (CMCS) as water-retaining agent,rhamnolipid (RL) as wetting agent, and cocamidopropyl betaine (CAPB) as foaming agent to the binder molasses solution (TM). The orthogonal experiment was used to optimize the ratio,the performance was tested by experiments such as contact angle,solidified layer hardness,and dust suppression efficiency,the structure was analyzed by characterization methods such as FT-IR,SEM,and thermogravimetry,and molecular dynamics simulation was carried out using Materials Studio software. The experimental results showed that after treatment with the dust suppressant,the hydroxyl content on the surface of the coal sample increases,and the hydrophilicity is enhanced. The gaps and cracks between coal dust are filled,forming a dense solidified layer. The dust suppressant has good thermal stability,and its internal structure remains stable in the extreme environment of open-pit coal mines. The contact angle of the dust suppressant is 35. 28°,indicating good wettability. The compressive strength of the solidified layer reaches 53. 56 kPa, which can effectively resist wind erosion. When the wind speed is 12 m/ s,the dust fixation rate is still over 90%,and the dust suppression effect is significantly better than that of other comparative samples,meeting the actual requirements of coal dust control in open-pit coal mines. The results of molecular dynamics simulation showed that compared with the water/ coal system, the thickness of the adsorption layer at the coal-water interface in the dust suppressant / coal system increases by 4×10 -10 m, and the diffusion coefficient D of water decreases,indicating that the dust suppressant enhances the wetting and adsorption ability to coal molecules. The dust suppressant is environmentally friendly,biodegradable,and easy to prepare,making it highly significant for coal dust control and the sustainable development of coal mining. 

Key words: coal dust,molasses,biosurfactant,foam dust suppressant,molecular dynamic simulation