Optimization Research of Air Decking Charge Structure for Bench Blasting based on JKSimBlast

Since continuous charge structure is adopted in the bench blasting of Heigou open-pit mining area, the boulder yield is high and the secondary crushing workload is large, which seriously affects the operation efficiency of the mine's subsequent production and loading shovel loading process. In order to optimize the open-pit blasting charge structure, the 2DBench module for open-pit mining in the blasting simulation software JKSimBlast is used. Taking the length and the position of the commonly used air decking as the research objects and the boulder yield as the evaluation index, 25 groups of experiments with two factors and five levels are designed with the hole depth of 17.5 m and the charge length of 10 m. The simulation results show that with the same air deck length, the boulder yield decreases first and then increases with the deck position moving down, and thus there is an optimal deck position. With the same deck position, the boulder yield decreases first and then increases with the increase of the air deck length. Furthermore, the optimal air deck length is determined as 2 m and the optimal deck position is 11.5 m from the orifice. Finally, field industrial tests with the optimized structure are carried out in 5 different blasting areas. The blasting muck pile photos before and after optimization in area 3 is selected as the reference group. By comparison, the results show that the optimized charge structure reduces the boulder yield by an average of 9.24% and effectively improves the blasting effect, which provides a useful reference for the selection and optimization of the charge structure in open pit mines.