Analysis of coal dust consolidation performance and mechanism based on in-situ screening of high urease-producing bacteria

Abstract

Coal dust accumulation poses a serious risk to personnel safety. Currently, Microbially Induced Carbonate Precipitation (MICP) technology is widely employed for controlling coal dust. This study aimed to isolate a urease-producing strain, Bacillus subtilis, from a coal mining area and investigate the optimal environmental conditions affecting urease activity. The optimal conditions were found to be a urea concentration of 0.648 M, NaCl concentration of 11.899 g·L−1, and a pH value of 7.602, under these conditions, the urease activity was strongest. As evidenced by the dust suppression effect test which reduced the mass loss of coal dust samples after using biological dust suppression materials under optimal growth conditions to 0.3%. Microscope scans showed that the optimized microbial dust suppression material produced mineral particles of larger size (approximately 40 µm in diameter), with precipitation primarily in the form of calcite. The x-ray diffraction analysis showed that the optimized dust suppression material produced mineralized products with large crystal size (43.2 nm) and high crystallinity (90.3%). Additionally, molecular dynamics analysis was conducted on the Z-axis relative concentration curves of coal molecules, solution molecules, and phospholipids before and after the addition of bacteria, the analysis showed that bacteria could enhance the wettability of water to coal dust at the molecular level. Overall, the experimental data suggested that this bacteria have significant potential for suppressing coal dust.