Study on migration law of dust on soil road surface in open-pit mine under airflow disturbance
In order to reduce the mass concentration of dust on the soil road surface in open-pit mines and improve the level of clean production,a start-up model of dust particles was established by using the gas-solid two-phase flow theory,and the start-up wind speed and variation law of dust were analyzed.The experimental research was used to verify the model,and the migration law and motion patterns of dust were determined.The orthogonal experiment range analysis method was used to stud-y the influence significance of each factor on the dust emission amount.The results show that the start-up wind speed of dust is functionally related to the dust particle size,moisture content,and load.The dust emission amount exhibits different varia-tion law under the influence of four factors:particle size,moisture content,load,and wind speed.It presents a nonlinear rela-tionship with both particle size and wind speed,a negative correlation with moisture content,and a positive correlation with dust load.The influence significance is ranked as follows:particle size>load>wind speed>moisture content.The dust mo-tion patterns are correlated with the wind speed and particle size.Under the wind speed of 5 m/s,the dust particles with the particle size of 0~75 μm tend to undergo the suspended motion,the dust particles with the particle size of 75~500 μm tend to undergo the jumping motion,and the dust particles with the particle size of 500~1 000 μm tend to undergo the creeping motion.The research results can provide theoretical guidance for the dust reduction measures.