Study On The Mechanism And Temporal And Spatial Distribution Of High Orepass Dust And Its Control Technology

Ore transported by ore pass is widely used in Metal mines,impact air follow produced in the process of falling ore,dust spread to the stope with the impact of air flow,seriously pollute the operating environment.Taking Lilou Iron Mine as the Research Background,combining the methods of theoretical analysis,field measurement,similarity experiment,numerical simulation and field application,the produce of the impact air flow and the pollution effect of the dust were studied and the influencing factors was analyzed.Through the study of dust removal mechanism by gas-water spray,a gas-water spray and dust-reducing system suitable for high ore pass is put forward and carried out in the field.By analyzing the force of ore particles and dust in the ore pass,we have obtained the equations of gas-solid coupling and the motion of dust,established the three-dimensional mathematical model of the impact flow and dust movement in high ore pass.According to the similarity principle,a similar model of high ore pass is established by combining the basic equations of impact air flow and dust movement,the distribution of impact air flow and dust under different unloading conditions is studied experimentally.The results show that:the maximum impact wind speed and the average dust concentration increase with the increase of unloading flow rate and unloading height.The greater the particle size range and the resistance coefficient,the smaller the impact air flow effect,the smaller the dust concentration.The dust concentration decreases rapidly with the increase of water content,and the decreasing trend is not obviously since the water content reaches 3.31%.The more the middle of the unloading,the impact of air will increase and increase.According to the theory of gas-solid coupling,the ore particles are treated according to the discrete system,the Newton's law is used to solve the motion of each particle.The gas is treated according to the continuous medium,the motion of the airflow is obtained by solving the Navier-Stokes equations.The temporal and spatial distribution characteristics of impact airflow and dust concentration are numerically simulated by DEM-CFD coupling method.The accuracy and applicability of the method are verified by comparing the measured results.Based on the analysis of the influencing factors,the gas-water spray is the most convenient and effective method to control the dumping dust of high ore pass.In this paper,the atomization characteristics of gas-water nozzles are studied experimentally,and the optimum gas-water flow ratio of gas-water nozzles is about 100?150.The results show that the average dust removal efficiency of the spray dust system can reach more than 80%,which can effectively improve the operating environment of the stope.