Study On Time Sequence Law And Identification Of Coal Gangue Rock Caving Flow In Fully Mechanized Top Coal Caving Face Of Extra Thick Coal Seam With Complex Structure

Intelligent coal mine is the inevitable trend of high-quality development of China’s coal industry.Automatic identification of coal gangue in fully mechanized top coal caving mining is the key technology of automatic top coal caving.The research of this technology has important theoretical value and practical significance for the realization of intelligent fully mechanized top coal caving mining.Based on the engineering conditions of fully mechanized top coal caving mining in extra thick coal seam with complex structure,this paper adopts the methods of field investigation,theoretical analysis and laboratory experiment to study the time sequence law and identification method of coal gangue rock caving flow in fully mechanized top coal caving mining in extra thick coal seam with complex structure.The research results are as follows(1)The occurrence and distribution characteristics of gangue in extra thick coal seam of typical mining area are analyzed statistically.The parameters of radionuclide type,content and radiation intensity in the gangue and roof rock of extra thick coal seam are sampled and tested on site.The results show that among the common gangue and roof rocks in the extra thick coal seam with complex structure,the radioactive intensity of carbonaceous mudstone is the largest,followed by sandy mudstone and kaolin mudstone,and the radioactive intensity of the two is equal,and the radioactive intensity of lamprophyre is relatively minimum.When the lithology of gangue and straight roof is the same,the radioactive intensity is similar.The radioactive intensity of coal is the lowest.(2)Based on the occurrence and distribution characteristics of gangue in extra thick coal seam,a similar experimental model is designed,and the flow mixing state and dynamic change law of coal,gangue and roof rock in the caving process of extra thick coal seam with complex structure are studied through experiments,and the time sequence law of coal gangue rock caving in extra thick coal seam with complex structure is obtained;the influence of occurrence parameters of gangue on the flow of coal gangue rock caving is analyzed The results show that when the occurrence horizon of gangue in top coal is low and the spacing is small,the coal gangue rock will appear the time sequence characteristics of mixed and gradual release.(3)The mixing law of coal gangue rock caving flow during normal caving is studied experimentally.It is concluded that the mixing rate of coal gangue isfluctuating in a fixed range,while the mixing rate of direct roof rises linearly.The variation law of the total gangue content of top coal is: when the gangue is discharged without sequence,the total gangue content fluctuates in a fixed range.When the gangue is released in time sequence,the total gangue content presents the rising stable continuous step rising change law;the direct top gangue mixing causes the total gangue content to increase linearly.(4)The radiation characteristics of natural rays in the process of coal gangue rock caving in ultra thick coal seam with complex structure are studied by experiments.The results show that the radiation intensity is relatively stable in the non time sequence influence area;in the time sequence influence area,the radiation intensity is still relatively stable,but the radiation intensity increases significantly,showing a step-by-step rise;in the direct roof mixing area,the radiation intensity is gradually increasing The change trend is gradually increasing.Based on this,the paper puts forward the identification method of coal gangue rock in fully mechanized top coal caving face with complex structure and extra thick coal seam,which takes the natural gamma ray radiation intensity value as the identification parameter.(5)According to the above research,the field test scheme of coal gangue identification in complex structure and extra thick coal seam is designed.The paper has 69 figures,34 tables,and 91 references.