Study On The Hole Stemming Theory Of Blasting And The Modification Of Stemming Material In Open Pit Mine

The stemming of blasting hole in open-pit mine plays an important role in deep hole bench blasting,which can improve the utilization rate of explosive energy,optimize the fragmentation distribution of upper bench,and reduce the hazards of flying rock and blasting noise.Therefore,this thesis carried out the research on the mechanism and modification of the stemming material of the hole in the open-pit mine.In the study of the mechanism of hole stemming in open-pit mine,this thesis integrates the current mechanism of hole stemming,and expounds the deformation,destruction and movement caused by detonation based on impact dynamics,shock wave compression mechanics and rock dynamics.In this thesis,the magnitude of detonation wave transmission along the axial length of the stemming body is studied,the process and results of the compression of the stemming body by detonation are studied,and the mechanical process of the stemming body moving upward along the hole driven by detonation wave is studied.In addition,this thesis carried out numerical simulation research on the movement of hole stemming,revealed the movement process of granular materials in the hole,extracted and analyzed the movement characteristics of the stemming.At the same time,this thesis adopts high-speed photography system to film the process of blocking punching of actual bench blasting in open-pit mine,and extract,sort out and analyze the motion characteristics after blocking punching.In the study of open-pit mine stemming material modification,this thesis introduces geopolymer into the field of open-pit mine blasting,and uses geopolymer to modify rock powder stemming,changing rock powder stemming from granular to consolidated body,and improving stemming performance.In study geological polymer modified rock powder block,this thesis draws on geological research in the field of polymer,to the water/cement ratio,cement ratio,sand ratio and other important formulation has carried on the preliminary classification,and on this basis further determine the alternative,the mechanics test,determine a suitable geological polymer modified rock powder block scheme.In addition,in view of the stemming of geopolymer modified rock powder,this thesis studies its reaction heat release,carries out the reliability test of the stemming material to the detonating tube,and discusses the safety of the stemming of geopolymer modified rock powder.Finally,this thesis carried out the field test of the open-pit mine blocked by geopolymer modified rock powder.In order to verify the superiority of the modified stemming material,three schemes were designed,combined with the actual operation conditions of the east open-pit mine,the more suitable one was selected,and the composite structure stemming experiment was carried out under the subsection interval charge.Under the condition of comparative test and high speed photography,it is proved that the modified stemming material can improve the stemming ability of gun hole.In addition,this thesis uses the software of blasting lumpiness identification to identify the corresponding blasting pile at the top of step,and finds that the stemming of modified rock powder can reduce the lumpiness rate at the top of step.