Powdered explosives

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Powdered explosives
Chemical composition
Explosive components
Other components
Physical Properties
Density
g / cm³ 		approx. 0.8 to 1.1
Oxygen balance
% 		approx. 0
Heat of explosion
kJ / kg 		approx. 4000
Steam volume
l / kg 		from 900 to 1000
Specific energy
(l · MPa) / kg 		about 1000
Detonation velocity
m / s 		from 2500 to 4000
Explosion temperature
K 		unknown
Property comparison
Explosiveness low
Ignition sensitivity low
Steam volume high
price very low
credentials

According to DIN 20163, powdery explosives are a subgroup of commercial explosives and are used to detonate rocks and soil on a large scale. Powdered explosives are explosives in the form of powder that do not contain black powder .

composition

Powdery explosives are mostly ANC explosives , i.e. ammonium nitrate (AN) with the addition of a carbon carrier (C) e.g. B. mineral oil. Occasionally, for environmental reasons, vegetable oil is used instead of mineral oil, e.g. B. rapeseed oil . However, since pure ANC explosives are not sensitive to capsules, so they cannot be detonated with a detonator , they require a booster charge , consisting e.g. B. from a cartridge gelatinous explosive or emulsion explosive or from detonating cord for detonation . For this reason, powdered explosives are also mixed with explosives , trinitrotoluene and other more explosive explosives in order to achieve ignition with detonators . But there are also powder explosives based on TNT.

The powdery explosives for rock blasting are colored reddish for identification. The explosives are delivered in sacks or, in large-scale use, mixed on site by tankers, so-called mixed-load vehicles, and placed in the boreholes.

properties

The powdery explosives have on average the characteristic values ​​given in the adjacent table.

Powdered explosives have a low level of explosiveness , but generate high vapor volumes so that they are suitable for rock extraction. The blasted heap is optimally lumpy for machine processing.

application

Powdered explosives are used for the following purposes:

  • Blasting rock ( large borehole blasting )
  • for blowing up stumps
  • Culture blasting of the ground (e.g. dyke blasting in the event of a disaster)
  • For blasting underground powdery be weather explosives used, the lower upon detonation explosion generate heat and temperature to firedamp be avoided.

The advantage of powder explosives lies in the method of introduction. Above and underground, these can either be mixed as bagged goods or blown into the boreholes from so-called mixed loading vehicles. This allows powdery explosives to fill the boreholes more completely than is the case with other explosives. Problematic z. B. with large borehole blasting is the overloading of the borehole if there are fissures or hollow chambers in the rock. This can endanger the success of the blasting.

Trade names

Powdered explosives are sold under the following names:

literature

  • Josef Köhler, Rudolf Meyer: Explosives . Wiley-VCH, ISBN 978-3-527-28864-9 .
  • Wolf-Ingo Hummig: Textbook for the state-recognized special course in pyrotechnics. 3rd expanded and modified edition, Hummig Verlag, Peißenberg 2009, ISBN 978-3-931360-22-1 .
  • R. Biedermann: The explosives. Your chemistry and technology, second edition, published by BG Teubner, Berlin / Leipzig 1912.

Individual evidence

  1. ↑ Orica Germany GmbH (Ed.): Technical data sheet Exan . Troisdorf ( oricaminingservices.com ).
  2. ↑ Sprengstoffwerke Gnaschwitz GmbH (Ed.): Technical data sheet Permonex . Schönebeck.
  3. ↑ sprewa Sprengmittelwerk GmbH (ed.): Technical data sheet Wandex . Nordlingen.

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