Study On Optimization Of Blasting Parameters For High-level Caving Method Without Chassis In Chagangnor Iron Mine

Chagannor Iron deposit adopts bottomless high sublevel caving method for recovery,using no pillar method to collapse ore to form a cover rock on the 3185m horizontal layout of the roof project.The design of medium-deep hole blasting has a direct impact on the production cost,blasting quality and production safety of the mine.Through the engineering geological survey of mines,production status research,uniaxial triaxial tests of physical and mechanical parameters of ore rock,optimization analysis of blasting parameters of ANSYS/LS-DYNA,design of medium-deep hole blasting,and field tests,optimization of pillar-free high scores Deep Hole Blasting Parameters in Sectional Caving Method.The results were applied to the 3185m level roofing project with good results.The main results are as follows:(1)The uniaxial compressive strength of various cores in a mine is obtained in uniaxial test,and the elastic modulus of the ore is 27.386GPa,Poisson’s ratio is0.1127,the cohesive force is 16.66MPa,the internal friction angle is 63°,the elastic modulus of the surrounding rock is 98.779GPa,the Poisson’s ratio is 0.231,and the cohesive force is 7.25MPa,internal friction angle is 68°.According to the rock mechanics parameters.Combined with the results of the engineering geological survey,the empirical strength reduction parameter method was used to recommend the mechanical strength parameters of the ore body.(2)By simulating and comparing the single consumption q=0.40kg/m3,q=0.50kg/m3and q=0.60kg/m3of explosive,it is found that when q=0.50 kg/m3,the blasting stress value is the largest,the blasting effect is good,and the single consumption of explosive is q=0.60kg/m~3.(3)According to the mining technology conditions and the environment requirements for blasting,the mine deep hole blasting hole network layout plan is designed.(4)The field test of the blasting program used blasting site observation and blasting to monitor the influence of surrounding rock vibration and other technical means to evaluate blasting quality.The test results show that blasting is performed according to the optimized blasting parameters and the effect meets the engineering requirements.In this paper,the blasting parameters are optimized by numerical simulation,which not only solves the practical problems of the mine,but also provides reference experience for similar mines.