Abstract: The site test and the method of numerical simulation were combined together to study the distribution of flow field in deep sunken openpit mines. Based on actual situation of the mine， five site test points are required for the experiments in Shougang Shuichang Iron Mine to observe wind direction and wind speed of different vertical height. According to the site observation results， it shows that when the wind speed ranges from 1m/s to 2m/s， the comingwind goes into the stope from both southwest and northeast and form recombination circulation structure; when the wind speed reaches to 47m/s or even bigger， the wind direction of the five site test points is same with the direction of the comingwind， no recombination circulation has been observed in the stope. Furthermore， the geometrical model of orebody was established on the basis of Gambit technology， and the distributions of flow field of deep sunken openpit mines in different wind speed conditions were separately simulated by applying Fluent software. The simulation results show that， as the wind speed increases， the location of the local recombination circulation center increases gradually， meanwhile， so are the width of the range and the thickness of the center. The simulation results of dust mass concentration are in agreement with the site test results.

Key words: deep sunken openpit mines, distribution of flow field, recombination circulation, numerical simulation, site test