Experimental Study On Coal Cutting Damage And Dust Production Law

Mine dust as an inevitable product in the process of coal production and processing is one of the main causes of mine production disasters,and it is also an important factor that jeopardizes the occupational health of employees.In the production process of the underground mining face,the shearer cutting dust production is the largest source of dust underground,accounting for more than 50%of the total dust in the face.To this end,this paper starts from the source and analyzes the changes in the coal body's mechanical damage and dust concentration and particle size during the cutting process to provide a theoretical basis for dust prevention.Firstly,the mechanism of coal deformation and dust generation in the process of shearer cutting is obtained by referring to the literature;secondly,based on the independently developed simulation experiment platform of coal and rock cutting and dust generation,the single coal type is cut with different parameters of pick;the mechanical monitoring system is used to monitor the change of coal stress and the change of three-dimensional force of pick to determine the pick In the process of coal cutting,the law of coal body's stress destruction;using the dust concentration sensor and Malvern laser particle size meter to monitor the change of dust concentration and particle size,the law of coal cutting and dust production under different parameters is obtained;based on the difference of coal structure,by measuring the hardness parameters of different coal types,different coal types are used for cutting experiments,the coal types under different metamorphic degrees are obtained The distribution rule of dust particle size in cutting process is analyzed by infrared spectrometer and nuclear magnetic resonance experiment,and then the relationship between the micro chemical structure of different coal and the cutting dust production is explored.Based on the relationship between the micro chemical structure of different coal functional groups and the dust production,the relationship between the dust production and the mechanical damage of coal body is revealed the relationship between.The experimental results show that as the degree of coal metamorphism increases,the larger the cone angle,the greater the dust concentration,the larger the dust particle size distribution interval,the smaller the proportion of fine particle size dust,the better the degree of crushing;the greater the drum speed,The higher the dust concentration,the larger the proportion of the small particle size of the generated dust;the greater the traction speed,the smaller the dust concentration,and the larger the distribution range of the particle size of the generated dust,the smaller the proportion of the small particle size;From the perspective of micro-chemical structure,as the degree of coal metamorphism increases,the absolute content of-OH in the coal continues to decrease,the proportion of aromatic carbon continues to increase,the fat carbon continues to decrease,and the aromaticity increases,so it is different in cutting.In the process of metamorphic coal,the same type of pick,the higher the degree of coal metamorphism,the greater the dust concentration,and the larger the proportion of small-sized dust.This is due to the continuous increase in aromaticity and the higher the degree of aromatization.The higher the degree of metamorphism,the greater the proportion of small particle size dust produced during the cutting process.