Learn About the Various Kinds of Explosives Used in Mine Blasting
Many countries of the world wouldn't be as rich as they are if they didn't have valuable minerals buried deep within their lands. Minerals are precious and pricey commodities. Blasting comes in handy during the extraction of most minerals that lie in deep within the soil. In nearly all forms of mineral extraction, rocks have to be broken down systematically before reaching the target minerals. This process requires explosives. If you are thinking of investing in the mining industry, here are some types of explosives you will be paying for:
High and Low Explosives
Basically, explosives are chemicals that cause a chain of reactions when activated. These reactions are classified into two categories: detonation and deflagration. Low explosives burn or combust at subsonic speed, generating high amounts of gases as the bi-product of their reaction. They do not generate shock waves, and the reaction is referred to as deflagration. Low explosives are ideal for use in mines that are adjacent to dense human settlements because they do not produce shockwaves that often affect the stability of nearby buildings. A good example of a low explosive is black powder.
On the other hand, high explosives rely on detonation. During their chemical reactions, high explosives generate pressurised gases, high temperatures and shock waves. The shock waves travel through adjacent rocks at the speed of sound. They can affect the stability of adjacent structures, which makes them ideal for mining sites in remote locations. A good example of a high explosive is dynamite.
Primary explosives are extremely sensitive to heat, electricity, friction and impact. Any form of contact with these elements means that the explosive will go off and deliver the blasting effect. For instance, a primary explosive that is sensitive to impact can be launched from several metres away and will detonate upon impact with the target area. Examples of primary explosives include pentaerythritol tetranitrate and mercury fulminate.
Secondary explosives are extremely sensitive to heat. However, they only tend to explode and deliver the blast if they are present in a relatively large amount. A truckload of a secondary explosive has a higher chance of exploding than a relatively smaller quantity.
Tertiary explosives are fundamentally regarded as non-explosives. This is because they require high amounts of energy to trigger detonation. They are ideal for mines where you have a reliable and inexpensive source of heat or other form energy like electricity. For example, heat from coal can be used to trigger the explosion of ammonium nitrate in coal mines.
For more information, contact a drilling and blasting contractor at a company like Rock On Ground.