| Intelligent mining is the development direction of coal mining.Coal-gangue automatic recognition is the bottleneck of intelligent mining in fully mechanized top coal caving,and its research is of great significance.Based on the engineering conditions of fully mechanized caving mining in thick coal seam of Lilou coal industry,this paper studies the environmental characteristics and the factors affecting the automatic recognition of coal gangue in fully mechanized caving mining by means of field investigation,theoretical analysis and laboratory experiment.(1)Firstly,a systematic analysis was made on the environmental characteristics of the coal gangue fall in the fully mechanized caving face.According to the geological conditions of coal seam occurrence in the 1303 working face of Lilou coal industry,this paper analyzes the characteristics of direct roof lithology and thickness,floor lithology,the accumulation form of gangue at the side of goaf in the caving space,as well as the temperature,humidity and dust concentration;The movement characteristics of the support tail beam and the flow characteristics of coal gangue in the process of coal caving are analyzed,and the radionuclides in the coal and roof and floor of the working face are determined by the detection method.(2)Based on the analysis of the principle of coal gangue automatic recognition,combined with the environmental characteristics of coal gangue caving in fully mechanized top coal caving face,the influence of different factors on coal gangue automatic recognition is studied;The effects of background radiation,temperature and humidity on the radiation of natural radiation and the working characteristics of detector are analyzed;The characteristics of the natural ? radiation field and the influence of the detector's spatial position on the detection efficiency are analyzed.(3)Combined with the conditions of 1303 working face,the influence of various factors on the automatic identification of coal gangue is verified by the experimental method,and the influence law of temperature and humidity changes on the working stability of the detector is obtained;Coal seam floor rock has strong radiation,but the shielding effect of scraper conveyor on ray propagation weakens the influence of floor;Gangue in goaf will not affect automatic recognition;When the detection distance is less than 40 cm and the detection angle is less than 60 °,the detector position change and radiation counting curve have a high fitting degree,which is regular,and is conducive to the identification of gangue in the process of tail beam swing.(4)Under the condition of static state and falling,the longest time for detector counting to reach stability is less than 1s,the average value is 0.81 s,and the sensitivity of detector can meet the requirements of on-site coal caving;When the gangue content is 20%,the quality of the discharged gangue per second is 16.38 kg,at this time,the count value is 154 cps,which is 14.9% higher than the background count.It can clearly distinguish the coal and gangue,and meet the requirements of effective recognition of gangue in the coal caving face.(5)According to the above research,this paper designes the on-the-spot test scheme of coal-gangue automatic identification detector.The paper has 58 Figures,13 Tables,and 83 references. |
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