Effect double-primer placement for improving the fragmentation on harder material in stemming column: A case study

Abstract

The fragmentation is one of the indicator of the successful blasting operation, because the next step is loading the blasted material which is the equipment productivity is depend on the bucket fill factor. Greater size of material loaded means lower bucket fill factor. Lower bucket fill factor, lower equipment productivity. More crack due to blasting, easier loading equipment to dig it up. The explosive energy transferred to the surrounding caused radial crack first. Then the shock wave formed and travel through the crack. Higher Velocity of Detonation (VoD), higher detonation wave produced. Then, increasing distance from the source of VoD the energy is getting lower. The simply way to improve fragmentation is increasing the Powder Factor (PF), but it has any side effects. The double-primer placement with double deck method will improve the fragmentation while using the same value of PF.