Rock fragmentation variations with increasing extraction ratio in sublevel caving: a case study

Variations in rock fragmentation are very likely to occur a sublevel-caving operation. This study conducted comprehensive test an iron ore mine monitor fragmentation. The results show clear trend variations from start end of production ring. These suggest increase coarse and oversized fragments with increasing material extraction the rings that can be linked increased overburden drill hole deviations upper part rings. problems addressed by shortening length or directional drilling but need further investigations.