Effect of Casting Parameters on the Cast Percentage of High Bench Cast Blasting

To search the optimal row and column spacing for high bench cast blasting, experiments have been done at Hedaigou open pit. The results show that, for the high bench cast blasting particularly at Heidaigou, when the hole (column) spacing increases with fixed row spacing, the forefront throw-distance of muck-pile is almost the same. The cast percentage increases with the increase of hole density <em<m</em<, but it declines after <em<m</em< <1.6. The influence of row spacing on the throw-distance is bigger than that of hole spacing. Experiments also reveal that. To reach the best cast percentage, there exists optimal row and column spacing, which depends on the specific conditions of the testing bench, explosive charge and other parameters. At Hedaigou open pit, the value of optimal <em<m</em< could be the one between 1.45 and 1.55, depending on the particular experimental conditions.