Abstract
The blasting method is generally used in non-coal mine underground mining activity. However, blasting operations will result in massive release of several toxic and harmful gases, and these gases are of high concentration and difficult to exhaust as they can be rapidly spread and fully distributed in confined spaces, like stope and roadway, within a short time. In this paper, the Fluent software is used to analyze the distribution and diffusion regularities of those blast-induced gases. In order to facilitate the study, only CO is considered. The results indicate that with the increase of wind velocity in air inlet from 0.25 m/s to 4 m/s, the rate of CO concentration drop in the roadway type stope presents a linear tendency. The CO concentration after ventilating with wind velocity of 0.5 m/s is basically in line with the Chinese national safety standard, while CO concentrations in return air corner of the stope are still beyond the safety standard's limit. The CO concentration can meet the standard's requirement when the wind velocity is within the range of 1 m/s to 4 m/s, and the drop rates of CO concentration at 3 m/s and 4 m/s have little difference. On the basis of comprehensive analysis, the wind velocity in air inlet should be greater than 0.5 m/s, and less than 1 m/s.