The main ingredients of explosives are inflammable chemicals that should be carefully handled and should be handled by experts only. If handled by amateurs, explosives can cause severe damage and innocent and property. During the process of detonation, gases get released that expand rapidly giving off huge amounts of heat and energy. Oxygen is the main component of the explosive chemicals.
There are two varieties of explosives that are used; low explosives and high explosives.
Low explosives
The best example of low explosive is that of gunpowder. These types of explosives are manufactured by mixing combustible substances and oxidants that would burn at a very high rate. The rate, at which these burn, can vary between 2-3 cm per second or can even burn at the rate of 400 meters per second. The low explosives generate sufficient amount of heat as caused by rapidly expanding gases with an initial temperature triggering the reaction. The deflagration depends on the oxygen amounts in the immediate surroundings. If the deflagration is high, the process will result in detonation.
High explosives
High explosives involve the reaction between various chemical compounds that detonate rather than deflagrate. They produce supersonic shock waves that range between 1000 and 9000 m/sec. the chemicals used in high explosives use unstable chemical compounds from the nitrate group. When the sufficient amount of heat and mechanical shock is applied to these unstable chemicals, their molecular structure undergoes a transformation. The process results in products that release huge amounts of energy.
Dynamite is an outstanding example of high explosive. Dynamites use nitroglycerine and it is a highly unstable compound.
Priorities
There are nine chemical sequences, known as priorities, which constitute the whole detonation process in high explosives. The first part involves reaction between metals and chlorine, which gives out huge amounts of energy. The other steps include the reaction between hydrogen and chlorine, some metallic compound with oxygen, oxygen and carbon, oxygen and hydrogen, oxygen and carbon monoxide, self-reaction of oxygen, carbon and hydrogen. Each reaction is a chain process that gives out a lot of heat.
Since the reaction inside the explosives need a high amount of heat to get triggered, low energy explosions are carried out to generate subsequent high energy ones. Thus, explosion chains are formed to give the desired results.
Those compounds that have the qualities to become explosives must have these basic components
1. They can produce rapid expansion and subsequent generation of gases
2. They can produce an exothermic reaction, i.e., heat generation can be done
3. They are capable of undergoing rapid reaction
4. Initial reaction procedures such that the timing of the explosion can be controlled
Also explosives need to be highly toxic. For inflicting a high degree of damage, shrapnel is used in explosives. Shrapnel are small metal fragments that explode with the bomb and are designed to cause damage to living beings and property.
Since explosive have huge damage potential they should be handled carefully and should be used by experts only.
