Study On The Key Parameters Of Process In Full-mechanized Top Coal Caving Mining With Large Dip Angle And Specially Thick Coal Seam

Coal is the non-renewable resource,so we should mine coal as much as possibly and reduce waste of resources in its mining process.In the process of fully mechanized top coal caving,reasonable process parameters can greatly improve the coal recovery rate.At present,domestic and foreign scholars mostly focus on the stress distribution and strata development in fully mechanized top coal caving mining under the condition of large dip or extra-thick coal seam,however,there are so few studies on the process parameters of fully mechanized top coal caving mining with large dip angle and specially thick coal seam that they can not guide the field practice effectively.Based on the combination of physical simulation and numerical simulation,I studied the characteristics of coal gangue flow field,mining ratio,coal caving step and coal way in fully mechanized top coal caving face with large dip angle and specially thick coal seam in this paper to determine a reasonable comprehensive mining technology parameters,improve the coal recovery rate and reduce the waste of resource.The main research contents and achievements are as follows:(1)The physical similarity simulation experiment model was established to study the characteristics of coal gangue flow field and the recovery rate of top coal and the rate of coal gangue in different coal mining ratio and different caving step.The initial mining height was 4.0m,mining ratio is 1: 2.4,the caving step is the two-mining and one-caving method.(2)In view of the laboratory physical simulation test may be affected by environmental factors and human operation errors,the computer discrete element numerical simulation method is used to study the recovery rate of top coal in the different mining ratio and different caving step.The results verify the correctness of similar physical simulations in the laboratory.(3)The combination of theoretical analysis and discrete element numerical simulation are used to study the characteristics of coal gangue flow field and the recovery rate of top coal in different coal caving methods,coal caving times and coal caving directions to determine the reasonable caving method is that single round sequential caving mining when the coal seam inclination is less than 35° and double round sequential caving mining when the coal seam inclination is more than 35°The research results of this paper provide reference for the exploitation of fully mechanized top coal caving face in Mengjiayao,which is of great significance to ensure the safety and efficient production of mine.