Evaluation of dust fixation effect of urease-based biological dust suppressant and its field application

Widespread mining of open-pit coal mines has led to severe dust pollution, which degrades air quality and affects human health. Due to the drawbacks of existing dust suppression methods, there is an urgent need to develop a biological dust suppressant, which is based on urease-induced carbonate precipitation and has excellent potential for application in the field of dust management. The research developed a biological dust suppressant based on urease-induced carbonate precipitation technology. By using biological dust suppressant with different ureases, the dust suppression effect was determined and field applications were conducted. The optimal formulation of the dust suppressant was identified through experiments, and the evaluation of erosion resistance, calcium carbonate yield, hardness, permeability resistance, and crust thickness was conducted, elucidating the consolidation mechanism. After synthesizing the economic benefits and treatment effects of field use, it was found that the optimal ratios of the dust suppressant were 1.0 mol/L for urea and calcium chloride, 100 g/L for soybean flour, and the ratio of urease solution and cementing solution was 1:1 when used; the calcium carbonate yield of the specimen treated by EICP (SCU) was as high as 7.49 %. In an alternative phrasing, after undergoing tests for resistance to wind and rain erosion, the mass loss rates were recorded at 0.24 g m^-2·min^-1 and 156.51 g m^-2·min^-1. When compared to the treatment with pure urease, there was a significant improvement in wind erosion resistance by 90 % and in rain erosion resistance by 25.53 %. Field applications have revealed that the distribution of calcium carbonate is uneven and exhibits a positive correlation with hardness, penetration resistance, and the thickness of the crusts formed. This is due to the macromolecular organic matter in crude urease, which not only can form a spatial mesh structure and play a bonding role, but also can provide nucleation sites for urease-induced production of calcium carbonate, promoting the precipitation and aggregation of calcium carbonate, so that the strength is improved.