Reef drive development in a chrome mine using Nxburst/Nonex Rock Breaking Cartridges. Sequential timing using the Maxclip 5 way clips. 4000ms down-the-hole, 200ms surface delay. Burden and Spacing of 500mm, 1.3m effective drill depth, 1.3m advance. No shockwave or arblast overpressure, Peak Particle Velocity (PPV) of 1.88mm/s measured at 15m.
- Fly rock less than 10m from blasting event
- Muck pile on the face
- Fragmentation of 250-300mm
- No back break or over break leaving the hanging wall
- Foot wall and side walls competent (no fractures) for a safer mine