Optimization of Medium-Length Hole Blasting Parameters Based on Blasting Crater Test
A certain copper mine adopts sublevel open-stope medium-length hole blasting for ore falling.In order to improve the blasting quality,blasting crater tests of single-hole series and multi-hole simultaneous blasting with different hole distances were carried out according to Livingston blasting crater theory.Based on the test results,industrial tests of medium-length hole blasting were designed to determine reasonable parameters which are conductive to reducinf unit explosive consumption and improving the blasting effect.The critical buried depth of the charge obtained by the blasting crater test is 0.964 m,the optimal buried depth is 0.470 m,the optimal blasting crater radius is 0.429 m,and the optimal ratio of hole spacing to the optimal crater radius is 1.64.For the medium-length hole blasting,the optimized hole bottom distance is 2.6-2.8 m,and the hole row spacing is 2 m.In the industrial test of medium-length hole blasting,when the row spacing of some holes is increased to 2.2 m,the block rate is not improved,and the blasting effect is good.The actual unit consumption of explosives is reduced from 0.47 kg/t to 0.39 kg/t.