Investigation of dust distribution patterns in open-pit coal mines under varying wind speed and air humidity

Abstract

Dust pollution in open-pit coal mines presents substantial environmental and occupational health hazards, requiring effective control measures. Although previous research has thoroughly investigated the correlation between wind speed and dust mass concentration, the influence of air humidity and its interaction with wind speed remains insufficiently studied. This investigation examines the effects of wind speed and air humidity on dust mass concentration and analyzes their combined impact through field observations and numerical simulations at the Pingshuo open-pit coal mine. The field data underwent analysis using Spearman’s rank correlation coefficient and Exploratory Factor Analysis (EFA). The analysis revealed that wind speed and air humidity significantly impact dust mass concentration. Nonlinear curve fitting further elucidated trends in dust mass concentration. Numerical simulations using Fluent software and Large Eddy Simulation (LES) were conducted to analyze dust distribution characteristics under individual variable influences. Results indicate that increasing wind speed generally decreases dust mass concentration within the open-pit mine, while increasing air humidity tends to increase it. Combining field monitoring with numerical simulation results demonstrated that dust mass concentration within the mine pit reaches its lowest level when wind speed is approximately 1.5 m⋅s− 1 and air humidity is about 45%. These environmental conditions are conducive to inhibiting the rise in dust mass concentration within the open-pit mine.