Study On Dust Distribution And Control Of Belt Conveyor In A Large Metal Mine

With the continuous development of the national economy,the growing demand for mineral resources,forcing most mines to increase production,due to the increase in production,ore transportation task is more and more heavy,most mines began to use belt conveyor for underground ore transportation.Belt conveyor in operation will produce a lot of dust,in the role of airflow,dust will spread to other roadways and working face,serious pollution of the underground working environment,the health of underground staff has a greater hazard.In the transport roadway,the drop point and transfer point is the largest dust production point,the dust concentration is far more than the national standard,research underground belt transport roadway dust diffusion mechanism,take effective measures to reduce dust to improve the underground working environment is of great significance.Based on a large metal mine underground belt haulage roadway as the research background,using theoretical analysis and derivation,field investigation and measurement,numerical simulation and field application of a combination of research methods,the underground belt haulage roadway dust concentration distribution and transport laws were studied.According to the theory of gas-solid two-phase flow,combined with the data measured in situ,the physical model of underground haulage roadway was established,and the distribution of dust in the roadway under different boundary conditions,such as different wind speed,different belt running speed,different wall conditions,different water content of ore,different drawing height and different drawing speed,was simulated by Fluent software.The results show that the dust concentration in the tunnel is the lowest when the average wind speed is 3m/s;When the water content of the ore is more than8%,the dust concentration is low;The dust concentration in the roadway is proportional to the running speed of the belt,the drawing height and the drawing speed;The dust concentration in the trapped wall is lower than that in the rebound wall.In this paper,after the comparative analysis of various dust removal measures,the economical,reasonable and efficient spray dust removal is selected as the main dust removal measures,and the comparative test of dust removal effect between ordinary water spray and gas-water spray is designed.The results show that the control effect of gas-water spray on whole dust and respiratory dust is much higher than that of ordinary water spray.According to the results of numerical simulation,combined with the field investigation of a large-scale metal ore underground belt transport roadway,a series of dust control measures were formulated,such as strengthening the sealing of ore fall point and transfer point,installing gas and water spray on the surface of belt conveyor and roadway section,cleaning and dust-proof at the bottom of belt.After the dust removal measures were installed and implemented,through the comparative analysis of the dust concentration measurement results in the transport roadway before and after dust removal,the dust concentration at the falling point in the belt transport roadway was reduced from 60.5mg/m~3 to7.5mg/m~3.The dust removal effect was significant and the operating environment in the roadway was greatly improved.