New type of sawdust-based dust suppressant during tunnelling and underground space: Preparation, characterization and engineering application

Abstract

In the process of underground tunnel construction, dust is the main killer endangering the safety and health of workers. New polymer dust suppressant materials have been proved to be an effective means to reduce dust concentration in restricted space. This study, based on the principle of waste utilization, is aimed at revealing a new degradable super absorbent dust suppressant (AA-SW-AMPS/ND), which is prepared by means of microwave-assisted chemical crosslinking with sawdust of China fir as the raw material. The micro morphology, reaction mechanism, water absorption and retention of AA-SW-AMPS/ND are studied through SEM, FTIR and swelling kinetic experiments. The product performance test shows that the dust suppression rate of AA-SW-AMPS/ND exceeds 95 %. The swelling rate in distilled water is more than 400 times, and the swelling rate in 1 % salt solution is maintained at about 100. After spraying AA-SW-AMPS/ND, the sample is in natural environment for 168 h, and the mass loss is less than 10 g; The synergy combustion performance time with coal sample is prolonged by about 50 s. By combining the new dust suppressant and its automatic adding device with the spray device, remarkable results have been achieved in the dust control of the fully mechanized face in the North seventh mining area of Tianchen coal mine. The average dust reduction rates of total dust and respirable dust have reached 90.07 % and 85.43 % respectively. The dust suppression and wetting mechanisms of AA-SW-AMPS/ND are explained by MS simulation, and the simulation results are consistent with the above experimental ones. This dust suppression method can potentially be applied in power plants, quarries, and other underground space environments.