Types of Explosives

The products used as the main borehole charge can be broken into three generic categories, dynamite, slurries, and blasting agents such as ANFO (Figure 17). A fourth, very minor, category will be added to the discussion, which is the binary (or two-component) explosives. Although the volume of binary explosives sold annually is insignificant when compared to the other major generic categories, its unique properties warrant its mention.

The term “high explosive” most often refers to any product used in blasting that is cap sensitive and that reacts at a speed faster than the speed of sound in the explosive media. The reaction must be accompanied by a shock wave for it to be considered a high explosive. All the generic categories discussed in this section are high explosives from the standpoint that they will all detonate.

A blasting agent is a classification based on storage and transportation and is a sub-class of high explosive. Explosives that are blasting agents are less sensitive to initiation and therefore can be stored and transported under different regulations than what would normally be used for more sensitive high explosives. ANFO is most often called a blasting agent but does not detract from an explosive’s ability to detonate or function as a high explosive.