Exploration of the microbial dust suppressant application in open-pit coal mines: Dust source conditions and application processes

To promote large-scale application, this paper studied the influences of different dust source conditions and application processes on microbial dust suppressant. Results showed that microbial dust suppressant could adapt to various dust source conditions. The wind erosion rate of samples did not exceed 47 g center dot m - 2 center dot min - 1 after a single spraying volume of more than 1.25 L center dot m - 2 and more than 4 spraying times. The change of CaCO3 crystallinity (about 6%) and crystal forms led to the change of hardness and thickness of the cemented layer (about 12-24%). The crystallization process of microbial dust suppressant is an important factor affecting performance, which is mainly regulated by saturation. In addition, the contact distribution mode of CaCO3 between particles and its corresponding pore was put forward. CaCO3 deposited by surface contact was the key to improving dust suppression performance. Under the background of large-scale application, 1.25 L center dot m - 2 and 2 times for spraying were more suitable.