| Liquid explosive has the advantages of strong fluidity,small critical diameter and good detonation transmission performance,which can effectively solve the charging problem of deep holes with large dip angle in coal mines,provide conditions for repeated blasting of single hole in rock mass,and significantly improve the volume fracturing effect of rock.For this reason,the research and development of liquid explosive for coal mine and the test of its explosive performance are carried out.By means of theoretical analysis,laboratory experiment and field practice,the systematic research on the selection of components,the control of crystallization point,the adjustment of density,the determination of explosive performance parameters and the test of rock breaking by blasting are carried out,which provides the basis for the application and promotion of liquid explosive in coal mine.The formula of liquid explosive used in coal mine is determined,and the control of the content of sodium nitrate on the crystallization point temperature of solution is studied.With the increase of the content of sodium nitrate in solution,the crystallization point temperature of solution first decreases and then increases,and the content of sodium nitrate in the basic formula of water gel explosive is 50%.The crystallization point temperature of liquid explosive can be controlled at 16.9℃,which is suitable for the mining temperature environment of coal mine;Using 0.15%sodium nitrite as density regulator,the bubble of explosive solution is stable,the density is controlled at about 1.12g/cm~3,the detonation speed is 4450m/s,the detonation temperature is 1834.91℃,and the detonation heat is 2602.62kJ/kg,all of which meet the performance standard of coal mine safety explosive.The coupling charge structure of liquid explosive used in coal mine improves the rock breaking effect.At the same time,the time for the explosive to reach the peak value of detonation pressure is relatively long,which prolongs the action time of stress wave and improves the energy utilization rate of explosive.Based on the on-site technical practice of liquid explosives used in coal mines,the initiation performance and rock breaking effect are tested and analyzed.The results show that under the same charge,the explosion power of liquid explosives,water gel explosives and emulsion explosives used in coal mines is equivalent,and the fracture shape of the surrounding rock of the hole wall is basically the same.The configured liquid explosives meet the performance requirements of the coal mine safety explosives,which is the basis for the application of liquid explosives in coal mines It can be used for reference.There are 123 figures,28 tables and 72 references in this paper. |
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