Blast Parameter Optimization Study Based on a Blast Crater Experiment

The blasting quality and the rock volume blasted directly affect the cost of mines. A small charge-forward blast crater experiment was conducted to study the relationships between the rock volume blasted, the explosive unit consumption, the bulk yield, and the depth ratio. The results showed that the rational resistant line or explosive charge depth should be 0.86 times the optimal resistant line. Based on theoretical analysis of the large spacing of the holes and the small resistance line, the uniform design method was used to conduct the lateral blasting crater tests. The relationship equations among the blasting parameters, the blasting volume, and the bulk yield were obtained by regression analysis. The results illustrated that the rock volume blasted was negatively correlated with the bulk yield. The contribution rates of the resistance lines and the spacing of the holes to the blasting volume regression were 32.4% and 13.9%, respectively, and to the bulk yield regression were 65.0% and 0.256%. The impact of the resistance line on the blasting volume and the bulk yield was more significant than that of the spacing of the holes. The blasting effect of the rectangular blast hole arrangement was better than that of the square pattern. The blasting technology of large hole spacing and a small resistance line could achieve a better blasting effect while ensuring a higher rock volume blasted. The economical and reasonable blasting parameters were determined as the hole spacing of a=8.5 m and the resistance line width of W=5.5 m, with the rock volume blasted of 413.1 m3 and the bulk rate of 0.218%. This method provides an effective method for optimization of the blasting parameters and has important guiding significance for efficient and economical mining.