ABSTRACT
One of the groups of parameters that can be controlled by the technicians in blastings is that of the explosives. The selection of the type of explosive forms an important part of the blast design and, consequently, the obtainable results. To start with, one must choose the lowest cost explosive with which the work at hand can be carried out. The comparative costs of the explosives per unit of weight, with Ammonium Nitrate as a reference drawn up from that of Wright. Rocks are classified in four types, and the recommended selection criteria are: Resistant massive rocks, highly fissured rocks, Rocks that form blocks and Porous rocks. For a blast design using a fixed hole size requiring an explosive or explosives of a particular bulk strength, the lowest blast cost will be achieved by using the explosive having the required bulk strength at the lowest cost per unit length of loaded blasthole.
