Mechanism of blasting without a compensating space
As a rule a free “compensation” space remains between the blasted ore and the solid rock. We recommended that in blasting without compensation space the same blasting parameters should be used as in breaking down with a free compensation space. This is confirmed by industrial practice.
Under very poor conditions the first group of blast holes is operative because the stored ore supports the solid rock. Apparently the first layer requires more explosive that the others (2–3 times as much, to judge by experience ).
Optimum fragmentation corresponds to optimum compensation. The appropriate sizes of the broken down layers are given in this article.
The author determines the maximum possible thickness of the solid ore being blasted from the condition that springing charges are not used.
Breaking-down vertical blast holes is more flexible than by horizontal ones, because in the latter case the layer of stored ore is limited in size.
KeywordsBarren Rock Solid Rock Blast Hole Break Layer Cement Block
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