7-Given the following: (16 points) •Gold mine : 10 metre bench •Well jointed, wet and hard rock •Will be excavated by shovel using single pass of 10 metres - Medium throw required •Tonnage factor of broken ore: 0 .38 m3 / tonne •Area to be blasted: 200 m (length of bench face) x 100 m (width) Find : Drill hole diameter: a common drill hole diameter would be 102mm (4 inches) Stemming length: Burden
