High-Explosive Compositions

High-Explosive Compositions

This group is created from simple high explosives such as those listed here, Initial Detonating Agents and Non-Initiating High Explosives.

Binary explosives are created by mixing explosive compounds, sometimes with addition of a non-explosive substance. Many are designed to have melting characteristics which permit them to be placed in shells and bombs in their liquid state and they are almost always entirely used for military purposes. The first was likely a 60/40 mixture of picric acid and dinitrophenol developed by the French to replace pure picric acid bursting charges. Further on, mixtures of ammonium nitrate and TNT called Amatols, was in widespread use to ration out the relatively scarce TNT. When TNT became more widely available, new binary explosives utilizing TNT as a carrier for more explosive compounds came into use. Among these are Tritonal, a mixture of TNT and flake aluminum; Tetrytol, TNT, and Tetryl; Pentolite, TNT and PETN; Pecratol, TNT and ammonium picrate; and Cyclotol, TNT and Cyclonite.

Plastic explosives are devised by coating of particles of a high-explosive compound with a waxy material. The resulting substance can be loaded inside cavities of detonators, shells, bombs and other devices by pressing, or can be molded into blocks for blasting and demolition purposes. Plastic blasting explosives are made soft and are puttylike in texture so they can be molded by hand and conform to the shape of an object or tamped with ease into a cavity.

Blasting explosives include a number of high-explosive compositions, foremost with characteristics of increased safety, low cost to manufacture and power that make them suitable for general use. They are also known as commercial explosives, distinguishing them from military explosives. Nitroglycerin was once used as a blasting explosive but its great sensitivity to impact or friction led to many injuries. It was replaced with dynamite and blasting gelatin which are typically safer, respectively patented by Alfred Nobel in 1867 and 1875. Both have been improved and are widely used today. Dynamites are made by mixing nitroglycerin with an inert filler or with an active substance that contributes to the explosive effect. Blasting gelatin is composed of nitrocellulose colloided with nitroglycerin. Gelatin dynamites are made by combining blasting gelatin with inert or active fillers. Ammonium nitrate explosives are composed of ammonium nitrate which is made more sensitive to detonation by addition of various materials. They produces an exceeding amount of gas when detonated, giving them an effect of heaving or pushing. Blasting explosives are used for mining, quarrying, tunneling, ditching, removing stumps, demolition, and many other civilian work activities.

Low-flame-temperature explosives are blasting agents with special formulation to cause them to explode with a flame so low in temperature and is so short in its duration that it does not ordinarily ignite mixtures of gas and coal dust in the air. These explosives are used in coal mining, when these conditions are present, and have thus contributed greatly to safety in mines.

References and Further Reading

  • The American Peoples Encyclopedia ©1960
  • Further Reading

  • U.S. Bureau of Mines
  • explosion
  • explosive
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