Abstract: In order to analyze the dust migration laws and guide the design of dust control system in long-distance blasting excavation roadway,based on the 1100 excavation face in a metal mine,a 1∶1 geometric model is established to conduct the CFD simulation,to analyze the air flow field and boundary conditions.According to the model applicability and the air flow field distribution characteristics,the RNG k-ε turbulence model is selected to simulate the air flow field in 1100 excavation working face,the simulation results show the dust volume fraction in the blasting space is low than 10%,which determines that using the discrete phase model to simulate the dust unsteady movement in the blasting space is suitable.The dust diffusion law,dust sedimentation law and dust concentration changing law are obtained in the scope of 0~60 m nearby the excavation face.The results show that the dust concentration decreases when the height increases from 0.5 to 4 m,and the dust concentration distribution has a obvious demarcation in the vertical direction,along the roadway,the dust concentration firstly increases and then decreases.The dust particle with the diameters under 10 μm is evenly distributed in the space,and the sedimentation quantity shows a trend of "decrease-increase-decrease-increase" along the roadway,while for the dust particles with diameters of 10~200 μm,the sedimentation quantity shows a trend of "decrease-increase-decrease".Dust particles with diameters of 15~200 μm almost completely settle.In the early blasting operation within 5 min,the dust concentration along the roadway sh〖HJ〗arply decreased,and gently decreases with 5~50 min.The high concentration area stays within 0~40 m and dose not migrate along the roadway.The migration laws show that 10~20 m is the air dust jet vortex area which strongly affects dust diffusion,sedimentation and concentration variation.In order to investigate the precision of the simulation results,during the blasting period,the AKFC-92A Dust Sampler and the CCHZ-1000 Automatic dust detector are set up at 20 m and 25 m to detect the dust concentration.The actual measurement values are basically consistent with the simulation values,which indicates the simulation results is reliable.

Key words: Long-distance roadway, Blasting, Dust migration, Numerical simulation