Parameters Optimization Of Supporting And Blasting For Open Stoping And Filling In Xiaoguanzhuang Iron Mine

The rock and ore in Xiaoguanzhuang iron mine is loose and cracked.Since production,the mine used non-pillar sublevel caving method to extract ore in a longtime.With the production continue and the depth of extraction enlarge,the underground pressure become more and more obvious,the main shaft and 1#auxiliary shaft has taken place some displacement and threatened both the underground extraction and the hoisting system.In order to limit the shafts displacement,the mine change mining methods to waste fill mining methods in the range of 150 meters out of the safety pillar.By filling open zone,the condition of shafts safety pillar stress has change and shrink the displacement of the shafts.In present,the mine use upward drift stoping with backfill to extracting ore in the range of 150 meters out of the safety pillar,but this methods productivity is low although with small loss ratio and dilution ratio.Therefor the paper is going to exploring a safety and effective extracting technology to suit the order of enlarge the ore output and improve the productivity.According to the experience of Laixin iron mine and some references,this paper try to research using open stoping and filling afterwards with cable supporting roof to realize the purpose of safety and effective extraction.In this methods,the key is reasonable cable and blasting holes parameters.So that,this paper will focus on researching these two main keys and conduct the production.In the research of cable parameters in supporting-roof draft,base on summarizing the cable support mechanism,rough determine the range of cable network and length by suspension theory and loose medium theory.After that,using FLAC3D simulating supporting-roof effect on different cable parameters and determine the reasonable cable parameters by the volume of plastic zones.In the research of fan-pattern blasting-holes parameters,firstly state the mechanism of the rock fragmentation by blasting.Then determine the range of blasting-holes parameters by both cracked circle radius and engineering design.Finally,using ANSYS/LS-DYNA simulating the rock fragmentation effect on different minimum resist lines and hole-bottom space.Comparing the rock fragmentation effect on different blasting planes,then decide the fan-pattern blasting-holes parameters.Base on above methods,finally acquire optimization cables and blasting-holes parameters for testing ore block and design the construction plane for testing ore block.