Practical Aspects of Cast Blasting at Bulga Coal Australia

"At Bulga Coal, the objectives of drilling and blasting are to maximise safety and to minimise the totalcost of mining. A recent audit of two overburden blasts established that the standard of drilling and blasting is excellent. No apparent hazards were identified. Laser profiling showed that highwall free faces are reasonably planar with some exceptions, thereby promoting uniform burden distances along front-row charges. However, in three isolated areas along one face, small burden distances existed. The mean and the standard deviation of errors in the collar positions of front-row blastholes was found to be 0.3 + 0.03 m. A borehole video camera was used to show that blastholes did not feature open bedding plane partings, cavities or damage produced by the blast in front of them."