Chemical Explosives: Chemistry in Action
by Yuvi K - December 16, 2023
Chemical Explosives: Chemistry in Action
Explosives are an essential element in modern industrial processes, from blasting through rock for mining purposes to demolishing structures. There is more to explosives than their explosive power, since they have many chemical and physical properties that make the choice of explosive for a particular purpose dependent on a variety of factors. In this article, we will take a look at chemical explosives and their use.
What are Chemical Explosives?
Chemical explosives are chemical substances that, when set off, undergo a rapid decomposition that results in the release of energy in the form of heat and pressure. This energy is strong enough to cause extensive destruction and poses a serious safety threat if mishandled.
Chemical explosives are usually composed of two parts: the fuel, which is the combustible material, and the oxidizing agent, which provides oxygen to help the explosive compound burn. The fuel and oxidizing agent are mixed together, often in a very specific ratio, to produce the explosive compound. Examples of combustion fuels include hydrocarbons such as alumino-sulphur, nitro-glycerine, or nitro-cellulose. Examples of common oxidizing agents are ‘dabursar’ (sulfuric acid), potassium perchlorate, ammonium nitrate, and aluminium powder.
The Mechanism of Explosives
Explosives typically work in one of two ways – by boiling or by detonation. Let’s take a look at each of these processes in turn.
Boiling
When an explosive is set off through boiling it typically contains fuel and oxidizing agent that breakdown progressively in a series of steps. During this process, the fuel and oxidizing agent react and the heat energy they generate vaporizes the fuel in the explosive mixture. This heat energy can then expand rapidly resulting in pressure being put on the vessel containing the explosive mixture.
Detonation
Detonation is a much faster process than boiling and is capable of releasing much more energy. During this process, the explosive material has to be broken down into small particles rather than the entire mass behaving as one. This process is initiated by a detonator that creates a shockwave. The shockwave then passes through a detonating cap and outwards, creating a path of destruction.
Classification of Explosive Mixtures
Explosive mixtures tend to have different properties and can be classified according to their sensitivity, brisance, and stability.
| Class | Definition |
|---|---|
| Sensitivity | Measures the likelihood of an explosive mixture detonating when subjected to a stimulus |
| Brisance | Measures the shattering effect of an explosive, its ability to release energy rapidly and shatter an object rather than simply pushing it aside |
| Stability | Measures how likely an explosive mixture is to deteriorate over time |
Uses of Chemical Explosives
Chemical explosives are used in many industrial processes.
Demolition
Explosives are often used in demolition jobs to safely and quickly tear down structures. This can range from the demolition of a bridge to the demolition of hazardous waste sites.
Mining
Explosives are commonly used in mining operations for blasting through rock in order to extract the desired materials. The explosive of choice will depend on the type of rock as well as how deep it is located.
Military and Police Use
Explosives are also used by the military and police forces for a number of purposes, from disabling vehicle engines to disarming bombs.
Conclusion
Explosives are an essential part of modern life and have a wide range of applications in industry, mining, construction, and military and police work. Chemical explosives are reliable and effective, making them a popular choice for many of these applications. However, as with all explosives, safety is of utmost importance and must be taken into consideration at all times.
