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RD
SEMESTER
NOTES ON EXPLOSIVES, BLASTING PRACTICES & GAS DETECTION
What explosive is used in mining?
ammonium nitrate
More than 90% of the domestic explosive and blasting agent formulations generally used are ammonium nitrate (AN) based (USGS, 2000). A mixture of ammonium nitrate and fuel oil, commonly known as ANFO, gained acceptance for blasting at surface mines. What are the 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. What is high explosive in mining? Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high explosives" and materials that deflagrate are said to be "low explosives". What are the two main types of explosives? 6.3 Explosives There are two major categories, high explosives and low explosives. Which explosives are used in mining in India? In India, three types of permitted explosives, namely (i) permitted (ordinary) or P 1 explosive (ii) permitted (equivalent to sheathed) or P 3 explosive (iii) permitted (for solid blasting) or P 5 explosive , are commonly manufactured and approved for use in underground coal mines. Is TNT used for mining?
TNT is one of the most commonly used explosives for military, industrial, and mining applications. TNT has been used in conjunction with hydraulic fracturing (popularly known as fracking), a process used to recover oil and gas from shale formations. What are the most powerful explosives? Azidoazide azide is the most explosive chemical compound ever created. It is part of a class of chemicals known as high-nitrogen energetic materials, and it gets its "bang" from the 14 nitrogen atoms that compose it in a loosely bound state. This material is both highly reactive and highly explosive. What explosive is used in blasting? DYNAMITE - A high explosives used for blasting, consisting essentially of a mixture of, but not limited to, nitroglycerin, nitrocellulose, ammonium nitrate, and carbonaceous materials What is the fastest explosive? The structures of cubane and octanitrocubane ONC is a high-velocity explosive and has a detonation velocity of 10,100 m/s. This makes ONC the fastest known explosive (see the table below). What chemicals are used in explosives? Examples of explosive and potentially explosive chemicals include: Compounds containing the functional groups azide, acetylide, diazo, nitroso, haloamine, peroxide, and ozonide. Nitrocellulose. Di- and Tri-nitro compounds. Peroxide forming compounds. Picric acid (dry) 2,4-Dinitrophenylhydrazine (dry) Benzoyl peroxide (dry) What is detonator in mining? A non-electric detonator is a shock tube detonator designed to initiate explosions, generally for the purpose of demolition of buildings and for use in the blasting of rock in mines and quarries. What is the composition of detonator?
Permitted explosives and detonators are explosive products which are approved by. Directorate General of Mines Safety (DGMS) for use in underground coal mines where there. is likely presence of inflammable atmospheres of coal dust and firedamp. Therefore, they.07-Jan- What are high vs low explosives? Explosives fall into two categories – high explosives and low explosives. The main difference between these two categories is the velocity of detonation. High explosives detonate at a rate greater than the speed of sound whereas low explosives deflagrate. Deflagration involves particle to particle burning. Is dynamite high or low explosive? Detonating explosives, such as TNT and dynamite, are characterized by extremely rapid decomposition and development of high pressure , whereas deflagrating explosives, such as black and smokeless powders, involve merely fast burning and produce relatively low pressures. Under…
What is fuse in blasting? The blasting safety fuse, employed to fire an explosive from a distance or after a delay, is a hollow cord filled with a mixture resembling black powder and designed to propagate burning at a slow and steady rate. The far end of the fuse is usually embedded in the explosive charge. What is the difference between detonator and fuse? Detonating cord (detonating fuse) resembles safety fuse but contains a high explosive instead of black powder. The first successful one, patented in France in 1908, consisted of a lead tube, about the same diameter as safety fuse, filled with a core of TNT. What is fuse and types of fuse? The fuse is the current interrupting devices which break or open the circuit by fusing the element and thus remove the faulty device from the main supply circuit. The fuses are mainly classified into two types, depends on the input supply voltages they are the AC fuses and the DC fuses. What are the different types of detonators used in mining? There are three categories of electrical detonators: instantaneous electrical detonators (IED), short period delay detonators (SPD) and long period delay detonators (LPD) How do explosive detonators work? EXPLODING BRIDGEWIRE DETONATORS (EBW) To function properly, a very large electric current must be delivered to the bridgewire in a very short period of time. This heats the wire through the vaporization phase so rapidly that the wire explodes with enough force to detonate the secondary explosive. What are the parts of detonator? The detonator typically contains several metal parts (the only known exception is French bakelite landmines placed in Southern Lebanon in the late 1940s, which have no metal at all).
What are the types of blasting in mining? The six controlled blasting techniques that will be discussed are (1) line drilling, (2) trim blasting, (3) buffer blasting, (4) smooth wall blasting, (5) air decking, and (6) presplitting.
Underground hydraulic mining[edit]
High-pressure water jets have also been used in the underground mining of coal, to break up the coal seam and wash the resulting coal slurry toward a collection point.[1]^ The high-pressure water nozzle is referred to as the 'hydro monitor'.[14] Compressed air/Air breaking A method originated in the United States for breaking down coal by compressed air. Air at a pressure of 10,000 to 12,000 psi (69 to 83 MPa) is conveyed in a steel pipe to a tube- or shell-inserted shothole. The air is admitted by opening a shooting valve and is released in the hole by the rupture of a shear pin or disk. The sudden expansion of the air in the confined hole breaks down the coal.
The type of blast design and explosive material consumption
depends on various factors; the most common factors are rock
type, density, strength, and damage condition of the existing
rock base
What are the factors affecting blasting? The major factors affecting the blast-casting results include: bench height, burden, dip angle of blast holes, powder factor, delay time interval, presplitting blasting effect, blasting patterns , and so on. There is a certain correlation among these factors.
A successful blast has to meet two basic conditions: (1) the
explosive in each blasthole is completely detonated, and (2)
detonator position, charge length, initiation plan, quantity of
detonators in each borehole, delay time, and so on are correct,
regardless of the types of detonators.
What are the different types of rock blasting?
Four controlled blasting techniques in use today are: pre-splitting, smooth blasting, cushion blasting, and line drilling.
Pre-splitting is a controlled blasting technique with applications
in open pit mines. The main objectives of pre-splitting in open
pit mining are: preventing/controlling back-break; controlling
excessive ground vibrations; and filtering the effects of
explosive gases from production blasting.
What is pre splitting? Pre-splitting can be defined as ' a technique using lightly charged, closely spaced holes to induce a fracture plane along a required design profile, which isolates the rock to be blasted from the surrounding rock mass '. The holes are generally fired instantaneously well in advance of any blasting in the adjacent rock. What is smooth blasting? A technique used in surface and underground blasting in which a row or closely spaced drill holes are loaded with decoupled charges (charges with a smaller diameter than the drill hole) and fired simultaneously to produce an excavation contour without fracturing or damaging the rock behind or adjacent to the blasted ...
Cushion blasting
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Cushion blasting, another type of controlled blasting that's
typically done after production blasting, uses a row of lightly
loaded "buffer" holes filled with crushed stone (stemming),
which reduces the impact on the surrounding rock as well as
the finished slope face.
What is line drilling blasting? A controlled blasting technique in which a row of closely spaced holes is drilled at the planned excavation limit. These holes are not charged with explosives. Such holes form a plane of weakness to which the final production row is designed to break.
Buffer blasting
