In order to control fragmentation, two important principles must be correctly applied. The proper amount of energy must be applied at strategic locations within the rock mass. The energy must also be released at a precise time to allow the proper interactions to occur.
The energy distribution within the rock mass is further broken down into two distinct areas. First one must have sufficient energy, by using the proper amount of explosives. To break the rock mass, the explosive must also be placed in a geometric configuration where the energy is maximized for fragmentation. This geometric configuration is commonly called the blasting pattern.
The release of the energy at the wrong time can change the end result, even though the proper amount of energy is strategically placed throughout the rock mass in the proper pattern. If the initiation timing is not correct, differences in breakage, vibration, air blast, flyrock and backbreak can occur. This discussion does not consider the effects of the timing of the release of the energy, the strategic placement of the proper amount of energy in a correct blasting pattern will only be considered in this section.
The study of the concerns of fragmentation go back to the early days of blasting. Blasters had realized that on some blasts, the energy was very efficiently used in the breakage process. On others, very little energy was used in an efficient manner and instead a great deal of noise, ground vibration, air blast, and flyrock resulted with little breakage. There have been many empirical methods that have surfaced over the decades, suggesting methods of design which would more efficiently utilize this energy. These design methods would also give the blaster a way of producing consistency in his results, by applying similar techniques under different circumstances and in different rock masses.
