Generation and diffusion characteristics of CO during excavation blasting in underground upward-inclination roadways: Based on field measurements and CFD simulations

Carbon monoxide (CO) generation during roadway blasting in underground mines poses a serious threat to the health and safety of workers. The generation and diffusion characteristics of CO during and after blasting must be better understood for its prevention and control. Herein, this study investigated the generation and diffusion characteristics of CO during blasting in underground upward-inclined roadways. The influence of several key parameters, including the wind velocity at the air duct outlet, the initial CO concentration, and the roadway inclination angle (0°, 30°, 45°, 60°, and 90°), on the diffusion of CO after blasting was analyzed. The results showed that the CO concentration after blasting exhibited double-peak characteristics corresponding to the blasting shock wave and press-in ventilation. After blasting, the moving velocity of the CO concentration peak exhibited a linear increase with the wind velocity at the air duct outlet. Meanwhile, both the peak CO concentration and the polluted length in the roadway increased linearly with higher initial CO concentration. Following these simulation results, the computational models for the concentration peak value and location, polluted length in roadway of CO were established. Furthermore, the area of the vortex zones formed at the roadway corners expanded as the inclination angle of the roadway increased. This enhancement in vortex size promoted the accumulation of CO within the roadway and prolonged the CO discharge time. This study provides practical reference for the efficient prevention and control of CO produced by roadway blasting in underground mines.