5 Conclusions and perspectives
The results of the study point out that Cast Blasting is likely to provide a significant increase in terms of stripping capacity. It is most advantageous to use with a powder factor in the range 1.01-1.26 lb/yd3. For the first row the boreholes should be drilled with a 10 degrees angle. The results are improved by a stemming that uses a gravel type material instead of the cuttings generated by the drill.
The Cast Blasting method has a significant economic advantage over the mechanical method for large overburden,
beyond 20 m (65.62 ft). This is consistent with the conditions of phosphate deposits that will be mined in the near
future.
However, Cast Blasting requires higher powder factors that inevitably lead to serious side-effects (mainly back break).
As said earlier, fixing this issue is essential to make the best use of the method. We planned a study to address this
problem.
We will also bring further improvements to this work by taking into account the effect of different delay schemes on
the Casting rate.