Study On Transport And Influence Factors Of Dust Migration In Open-pit Mines

With the rapid development of the economy,environmental protection has become a focus of social attention.As an important mining method in China,open-pit mining has caused increasing concern due to the dust pollution caused by transportation.This dust not only has an adverse effect on the health of workers and mining efficiency,but also pollutes the surrounding environment and affects the health and life of nearby residents.Currently,there is relatively little research on dust emission from open-pit mining road transportation,so this study can provide important theoretical guidance and reference for dust removal and reduction work in open-pit mines.Through on-site experiments,data mining and analysis,and grey correlation analysis,a grey correlation model of the factors affecting dust emission from open-pit mining transportation was established.The five factors affecting the concentration of dust emission from open-pit mining transportation were analyzed,and the order of the influence factors was determined as follows: wind speed,vehicle speed,dust load,dust moisture content,and temperature.By monitoring dust emission on-site in open-pit mines and using Origin software to perform nonlinear curve fitting on the measured data,the relationship between wind speed and dust concentration from open-pit mining transportation was obtained.To analyze the dust pollution caused by open-pit mining transportation in a targeted manner,fluid mechanics analysis and Fluent numerical simulation calculation methods were chosen in this study.The transport law of dust emission from open-pit mining transportation was comprehensively studied,and the effects of different wind speeds and directions on dust concentration,dust particle trajectory,external flow field wind velocity,and external flow field air pressure were analyzed.The following conclusions were drawn:The greater the wind speed,the greater the air flow velocity around the car,the more dust particles in the air flow,the denser the dust particle trajectory,and the higher the dust concentration.The height of the dust lifted increases with the increase of wind speed.Under different wind speeds,the order of the highest point of the dust particle trajectory is: 0m/s < 3.5m/s < 6.0m/s < 9.0m/s < 12.0m/s.From the dust particle trajectory chart,it can be seen that the higher the wind speed,the shorter the time it takes to reach the exit position of the calculation area.When the wind speed is0m/s,the longest time is 80.0s,and when the wind speed is 12.0m/s,the shortest time is 4.0s.At the same time,the difference in velocity between the high-speed and low-speed airflow regions increases significantly.When the wind speed is 0m/s,the minimum difference between the highest and lowest wind speeds is 4.0m/s,and when the wind speed is 12.0m/s,the maximum difference between the highest and lowest wind speeds is about 17.0m/s.When the airflow flows through the windward surface of the vehicle,it encounters resistance,the airflow gathers,and the dust concentration is high,and the air pressure is high.When the airflow reaches the corner of the vehicle,local separation occurs,forming a low-pressure zone.This local separation phenomenon will cause the airflow velocity to decrease and the pressure to drop.In addition,when the airflow flows toward the bottom of the car,due to the large curvature of the lower rounded corner,local separation occurs,forming a low-pressure zone.The paper has 35 figures,10 tables,and 68 references.