What is detonation in mining?
During detonation, explosives used in mining undergo rapid decomposition due to high temperatures and large amounts of constantly evolving gases and heat. The more gases accompanying the decomposition of explosives, the higher the pressure of the gases in the blast hole.
What is blast wave propagation?
It is an area of pressure moving supersonically outward from the source of the explosion. Immediately after the blast, the fore-end of the blast wave is headed by the shock waves, propagating in the outward direction.
What blasts do mines use?
What explosives are used for blasting? Dynamite, a nitroglycerin-based explosive, is rarely used today for blasting at surface mines in Illinois. Blasting agents account for almost 99% of the explosive materials used. ANFO, ammonium nitrate and fuel oil, is the most common explosive.
What is the blasting process?
blasting, process of reducing a solid body, such as rock, to fragments by using an explosive. Conventional blasting operations include (1) drilling holes, (2) placing a charge and detonator in each hole, (3) detonating the charge, and (4) clearing away the broken material.
What are types of explosives?
There are three fundamental types: mechanical, nuclear, and chemical. A mechanical explosive is one that depends on a physical reaction, such as overloading a container with compressed air.
Which explosive is used in underground mines?
The Director General of Mines Safety has approved Powergel P501 as a P5 type permitted explosive for use in degree I, II and III gassy coal mines/seams. Powergel P501 is a water resistant P5 type of permitted explosive. It can be used for solid blasting in all underground coal mines.
How mining methods are done in underground?
1) Longwall mining. 2) Room-and-pillar mining. 3) Blast mining. 4) Shortwall mining….overburden material.
- Bench and Fill (B & F) stoping.
- Cut and Fill (C & F) stoping.
- Stull stoping.
- Square-set stoping.
- Shrinkage stoping.
- Vertical Crater Retreat (VCR)
What is the difference between explosion and detonation?
An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Supersonic explosions created by high explosives are known as detonations and travel through shock waves.
What causes Shockwave?
A shockwave is caused by a rapid modification to the density of a medium, causing a pulse of kinetic energy to be transferred through the atomic matrix of the medium by sequential transmission of the energy from molecule to molecule.