Application of bacteria for coal dust stabilization

In the coal mines, the conducted activities are always associated with technical and natural hazards. One of the most dangerous sources of these hazards is the dispersed coal dust. Today, considering the successful application of bacteria in the engineering industries, the present study aimed at stabilizing and preventing coal dust entering the air using biological agents. Therefore, the effect of spraying Bacillus subtilis bacteria, as a calcium carbonate precipitator microorganism, on the surface of coal dust was evaluated. Accordingly, the certain volume of bacteria was sprayed on coal dust samples and their resistance against the wind was compared in two different speeds. The results showed the reduction of entering the coal dust into the air and this trend had considerable progress during 14 days. Spraying the bacteria improved the dust stabilization by 87% compared to control sample (dry coal dust) and the rising coal dust from the surface was about 40% less than the conventional methods. Besides, increasing the volume of bacteria led to faster forming and more durable calcium carbonate layer. In addition, X-ray diffraction (XRD) and urease test confirmed the formation of calcium carbonate layer on the sample surface.