Study On The Regularity Of Dust And Dust Characteristics Of Fragile Coking Coal

In the process of mining, the coal is easily broken, the amount of dust is large,the grain size is small, the dust is difficult to prevent. First, this article analyzed the physicochemical characteristics of easy breakage of coking coal.On the basis,according to the principle of similarity, similar material sample made easy breakage of coking coal, and using acoustic emission testing technology to analyze the failure characteristics of producing dust, and then easily broken coking coal gravity drop hammer experiment was carried out, the determination of the easily broken coking coal producing dust particle size distribution. Finally, easily broken mesoscopic pore structure of coking coal dust were determined. It is concluded that the pore structure characteristics. According to the conclusion of this paper, it can provide basic guidance for the prevention and control of the coal dust. The main research is as follows:(1) Analyze the source of pulverized coal (dust), studied the easy broken physical and chemical properties of coking coal, the results show that the affected by the different tectonic stress of coal, the macro and micro characteristics difference is big.The different volatile matter of coal samples in the same face shows big difference of content of fixed carbon.(2) Under the condition of acoustic emission testing,the different combination forms of coking coal similar material sample single compression producing dust on their respective burst characteristics were studied.The experiment results show that for different combination forms of similar material sample, a macroscopic crack and the broken position of outburst is always located in soft coal of similar material and hard coal similar materials, and soft coal of similar material damage degree is higher,the dust amount is larger.For different loading directions: parallel to the bedding direction load, crack spread shaped, nuclear dust source concentration.Perpendicular to the bedding direction loading, sample fracture extending in all directions, nuclear dust source dispersion.(3) The experiment of the determination of producing dust capacity and impact characteristics of coking coal has been carried, coking coal amount of raw coal dust production and coking coal uniaxial compressive strength.Gravity drop hammer test shows that under the same energy of coking coal dust production capacity is greater than the contrast of coking coal, coal sample proportion of tiny particles of dust associated with hammer energy, thus proposed the particle size range in 20.02～34.82μm (including gravity drop producing dust ratio is closer to the concept of"energy producing dust particle size of inflection point", research suggests dust particles mainly focused on "energy producing dust particle size inflection point"(6.62～105.25μm) nearby.The fallout characteristics grain size analysis shows that the fault and the mining cutting process affect the characteristics of the particle size of each sample point confirm the dust of the institute focuses on "energy producing dust particle size inflection point" near the point of view.(4) The use of low temperature liquid nitrogen adsorption experiments of different tectonic coal dust were analyzed, and compared the different pore characteristics of tectonic coal structure, from the Angle of qualitative and quantitative two different pore structure characteristics of tectonic coal dust are analyzed: the different location of the coal dust, ash content, due to the different geological structure and stress of different, the different carbon content, the pore size distribution, pore shape also has bigger difference;Broken pulverized coal and scales coal pulverized coal under the influence of tectonic stress is the largest, the highest degree in the pore structure of the complex. Factal dimension values and the complexity of the distribution of microscopic pore structure of coal dust were positively correlated.