Simulation Study And Application On Water Curtain Dust Removal Technology In Near Driving Face Of Metal Mine

Underground mining of metal mines have complex dust sources and high dust concentration.A large amount of respirable dust mainly silica dust is generated in driving face,which seriously affects the health of mine workers and the safety production of mineral enterprises.In order to effectively alleviate the problems caused by dust pollution,the theoretical analysis,numerical simulation and field test were used to study the water curtain dust removal technology in this paper which was based on the research progress of mine dust removal technology at home and abroad in recent years.It plays an important guiding role in metal mine dust control and water curtain dust removal technology optimization.(1)The necessity of dust removal and possible direction of dust removal were discussed by analyzing the sources,basic properties and hazards of dust in metal mines.The mechanism of water curtain dust removal was obtained by analogy with the action of single droplet to collect dust particles.The main factors affecting the dust removal efficiency of the water curtain system were determined according to the main components of the water curtain system,including the structure selection and nozzle diameter of the water curtain nozzle,airflow velocity and spray pressure in the tunnel.(2)Based on the gas-solid two-phase flow theory and Euler-Lagrange method,the software FLUENT was used to simulate the dust movement rule of the roadway near the tunneling face in metal mine.The data show that dust concentration decreases rapidly in a distance of 20 m from the driving face due to its own settlement,and then decreases slowly in a long distance.According to the simulation results and the dust distribution law obtained in field measurement,the optimal location of the water curtain dust removal system is about 20 m from the driving face.(3)In order to determine the optimal wind speed of the water curtain system,the droplet field distribution under different wind speed was simulated and analyzed.The wind speed can affect the migration and distribution of droplets in the water curtain,but has no obvious effect on the particle size of droplets.By comparing the concentration distribution of droplets formed by water curtain at different wind speeds,it is concluded that when the wind speed of tunnel is about 1.5 m/s,the influence of air flow on droplets can achieve better dust removal effect,for the water curtain set parameters provide reference for the selection of wind speed.(4)In order to determine the optimal spray pressure of the water curtain system,the droplet size,droplet speed and droplet mass concentration under different spray pressures were compared and analyzed.The size of spray pressure causes the change of the parameters of the droplet,and it is determined that when the spray pressure is 5 MPa,the indexes of the droplet field are more conducive to the dust removal of the water curtain system.(5)Combined with the actual mine of Linglong Gold Mine,the dust concentration after adopting water curtain dust removal technology was measured.The results show that the dust removal efficiency of water curtain system is 64.1% for total dust and 41.9% for respirable dust.The optimization method of water curtain dust removal technology in water curtain nozzle layout and water curtain water subsequent purification treatment was put forward,which is helpful to improve the water curtain system in metal mine field.