Study On Dust Distribution And Diffusion Mechanism In Open Pit Coal Mine

With the development of economy,the whole society demands more and more of the environment.In the production process of open-pit mines,a lot of dust will be produced in every link of blasting and mining.It not only damages the health of the workers in the pit,but also has a negative impact on the efficiency of the internal mining operation.Dust diffusion outside the pit will also affect the surrounding environment.In order to control dust pollution in open-pit mine,this paper systematically studies the dust-generating mechanism,distribution and diffusion law of open-pit mine dust by means of particle micromechanics analysis,computational fluid dynamics analysis,fluent numerical simulation calculation,field experiment,mathematical statistics and data analysis,economic and technological analysis,etc.The main factors affecting the control and control of dust pollution in open pit mines are the main problems.The main sources and classifications of dust in open-pit coal mine are studied.The dust-generating mechanism of different types of dust is analyzed according to the characteristics of different types of dust.Taking the truck dust during truck transportation as an example,the dust-generating mechanism of physical disturbance type dust source is studied through macroscopic force analysis.The influence of inversion layer on dust aggregation in open pit mine was studied,and the main influencing factors of dust aggregation under the influence of inversion were analyzed based on Froude number.Based on the fluid mechanics analysis,a three-dimensional model was established to simulate the dust accumulation and diffusion mechanism in open-pit coal mines by using Fluent fluid calculation software under Ansys.The effects of wind speed,wind direction,slope angle,pit depth and dump heightening on dust accumulation and diffusion were simulated.Based on the Stochastic Forest model,the influencing factors of dust pollution are analyzed.By calculating the weights of influencing factors,the weights of all influencing factors are obtained,and the main influencing factors of dust in open-pit mines are sequenced.By organizing on-site dust monitoring in Harwusu Open-pit Coal Mine,an on-line dust monitoring system with a mixed network of beta-ray dust detector and laser dust monitor is explored,which not only meets the requirements of monitoring accuracy,but also reduces the cost of networking as much as possible.Based on the analysis of dust monitoring data in Harusu Open-pit Coal Mine,the regional distribution and diffusion law of dust in Harusu Open-pit Coal Mine are basically found out.Based on Markov model,an evaluation model of dust emission intensity in open-pit coal mine is established,and the time series data obtained from monitoring system are processed.The model can not only deal with stationary numbers.It can also handle abrupt data of dust emission from open pit mines.Based on the dust escape rate,the influence of dust generated in open pit on the external environment is studied.The results show that not all particles can diffuse outside the pit.The main influencing factors are particle size,wind speed,wind direction,etc.Therefore,the method of accumulating dust emission in open pit can not be used to calculate the dust emission in open pit.Emissions;Based on the economic cost analysis,the influence of dust on the operation efficiency of open-pit mine was studied;the evaluation model of dust impact on the operation efficiency of truck transportation system was established,and the decision-making model of dust control measures input in open-pit mine was established through cost analysis.The main methods of physical and chemical dust suppression are summarized,and the technical specifications of curing agent dust suppression agents are studied experimentally.To sum up,this paper summarizes the rules of dust occurrence,accumulation and diffusion through theoretical analysis and numerical simulation,and then carries out field monitoring experiments in open pit mines.On the basis of analysis of experimental data,it further summarizes and improves the mechanism of dust distribution and movement in open pit mines,laying a theoretical foundation for dust suppression in open pit mines.It promotes the development of green mining in open pit mines.