Nowadays, considering the importance of coal as an energy source and hazards of extracting coal in mines, efforts of increasing safety in coal mines have been increased. Coal dust is one of the factors which increase the probability of explosion in mines and also is a health risk for mine workers. In recent years, many methods have been proposed for controlling dust that each had shortcomings and problems. Due to successful application of bacteria in engineering studies in recent years, in this research we try to use the biological factor for stabilization of coal dust and preventing the dust to hover in the air. Therefore, to reach this research’s goals, effects of Bacillus Subtilis bacteria as a calcium carbonate producing microorganism on the surface of coal dust was evaluated. For this purpose this bacteria sprayed in certain volumes on coal dust and samples were compared based on their resistance against to speeds of wind. The samples were divided in 4 different ages from 2 to 14 days and mass loss percent were calculated. The result showed an improvement in dust control which was more significant in 14 day sample. Spraying dust caused 87% improvement in stabilization of coal dust comparing to control sample and 40% better than the conventional method which is a\water spraying. Moreover, increasing the volume of sprayed bacteria improved the result and only 1.6% of the dust rised into the air. In this case, calcium carbonate layed formed faster on the dust and the 7day sample also showed good result. The XRD and Ureas test also confirmed the activity of the bacteria. Keywords : coal- coal dust- stabilization- bacteria- carbonate calcium- coal dust explosion- safety
