Experimental research on microbial dust suppressant for solidified dust based on MICP

In order to reduce the concentration of coal dust in open-pit coal mines, reduce and prevent the harm of coal dust, based on the microbial induced calcite precipitation solidification dust technology, the influence of environmental factors（temperature, pH） on the growth of Bacillus pasteuri was explored, and the effects of bacterial concentration, cement concentration and nutrient solution concentration on the solidification effect were evaluated by measuring the production of CaCO₃. Through the experiment, the matrix analysis method was used to optimize the proportion of Bacillus pasteuri microbial dust suppressant and a new type of high-efficiency and environmentally friendly microbial dust suppressant for mining was proposed. The results show that the suitable culture conditions of Bacillus pasteuri are 30 ℃-35 ℃, pH 7.5, and the microbial dust suppressant is suitable for opencast coal mines under high temperature and moderate alkaline environment; there was a positive correlation between the concentration and the bacterial concentration. With the increase of cement concentration (urea, calcium chloride), the generation amount of CaCO₃ increases and then decreases; Bacillus pasteurelli microbial dust suppressant has good permeability, strong wind resistance, water retention, rain resistance and other comprehensive properties; the optimization scheme of the composition ratio of Bacillus pasteuri microbial dust suppressant is: the OD₆₀₀ value of Bacillus pasteuri bacteria solution is 1, the cementing solution （urea, calcium chloride mixed solution）is 0.5 mol/L, and the nutrient solution is 2 g/L.