Study On Blasting Technology And Parameter Optimization For First Sublevel In Second West Mining Area Of Longshou Mine

This research project is based on the requirement of the project "Comprehensive Study on Safe and Efficient Economic Mining of Jinchuan Low-grade Mine".The purpose of the study is to provide a set of blasting technology and blasting parameters suitable for the first mining sublevel of second west mining area for the development of caving method.(1)In order to determine the preservation of blasthole in second west mining area of Longshou Mine,physical model tests and field tests were carried out based on the physical properties of ore and rock in second west mining area.The test results show that the blastholes in second west mining area of Longshou Mine are complete,and there is no need to worry about the impact of blasthole damage on mining blasting.Even if a small number of blastholes are damaged,the main failure mode is shrinkage and blockage.(2)Based on the similarity theory and combined with the original blasting parameters of second west mining area of Longshou Mine,the similarity model test was carried out.The direction of optimization of blasting parameters is basically determined by the test,and it is found that the burden of the original blasting parameters is too large at present.(3)Based on the previous studies,the parameters of blast burden,hole bottom spacing,array pitch,millisecond time and explosive quantity in the first mining sublevel of second west mining area were optimized.According to the principle of blasthole layout,the main blasting parameters of second west mining area are finally determined as follows: the burden is 1.7 metres long,the hole bottom spacing is 2.7 metres long,the array pitch is1.7 metres long,the edge hole angle is 35 degrees.In addition,according to the optimized blasting parameters,the layout of blastholes in the first mining sublevel of second west mining area of Longshou Mine is drawn,the mining blasting technology of this mine is expounded in detail.(4)In order to verify the rationality of the optimized blasting parameters,A numerical simulation model of burden and hole bottom spacing was established by using finite element analysis software Ansys/LS-Dyna.The numerical simulation results show that the optimized burden and hole bottom spacing are reasonable.Physical model tests have been carried out.The results show that the blasting effect of the experimental model with optimized blasting parameters is not significantly different from that of the actual mine blasting,This shows that the blasting parameters obtained in this paper have great guiding significance for actual production.Theoretical calculation,physical experiment and numerical simulation verify each other and prove each other's rationality.