View source for Gelignite

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'''Gelignite''', more commonly referred to as '''blasting gelatin''' or simply '''blasting jelly''', is an explosive material used in mining, as a safer alternative to [[dynamite]].

==Composition==
Gelignite consists of 20-50% collodion-cotton (a syrup-like material consisting of [[nitrocellulose]] dissolved in ether or alcohol) mixed with [[nitroglycerin]] or [[Ethylene glycol dinitrate|EGDN]], mixture often nicknamed "gelatine", 30-40% saltpetre ([[sodium nitrate]] or [[potassium nitrate]]), though some formulations use [[ammonium nitrate]] and the rest being [[wood]] pulp. The solid part of gelignite is sometimes called "dope". The exact composition depends on the type of gelignite necessary or by the manufacturer.

Other sources indicate 54%-63% nitroglycerine, 3%-5% collodion cotton, 26%-34% KNO<sub>3</sub>, 6%-9% wood meal and 0.5% chalk; another composition of the same name is 70% NH<sub>4</sub>NO<sub>3</sub>, 29.3% nitroglycerine, and 0.7% collodion cotton. 

On average, gelignite consists of 65% gelatine and 35% solid material.<ref>[https://ia802906.us.archive.org/25/items/lecturesonexwalk00walkrich/lecturesonexwalk00walkrich.pdf ''Lectures on Explosives'', Third Edition, 1902, by Willoughby Walke, p. 321]</ref>

==Properties==
===Chemical===
Gelignite burns slowly when ignited, though a basting cap is required to detonate it.

===Physical===
Gelignite is a white-ish paste-like  material, with a specific odor, though this is not universal. It does not dissolve in water, but may partially dissolve in organic solvents.

===Explosive===
Gelignite has an average detonation velocity of 6,500 m/s. Detonation of gelignite yields an average between 800 and 860 cubic meters of gas per kg or gelignite.<ref>''Introduction to Tunnel Construction'' Applied Geotechnics Vol. 3, 2010, David Chapman, Nicole Metje, Alfred Stärk, p. 171</ref>

It is more stable than [[dynamite]], but can still suffer from "sweating". Its composition makes it easily moldable and safe to handle without protection, as long as it does not enter in contact to anything capable of detonating it. 

==Availability==
Can be acquired by entities that posses explosive material license. In the United Kingdom, an explosives certificate, issued by the local Chief Officer of Police, is required for the possession and use of gelignite.

It is available under the name '''Frangex'''.

==Preparation==
Gelignite can be prepared by carefully dissolving nitrocellulose in a solvent, then carefully adding the nitrate ester, then the resulting slurry is mixed with the nitrate salt and the wood dust, until the desired consistency.

More information on its preparation can be found on [http://www.sciencemadness.org/talk/viewthread.php?tid=949&page=21 this SM thread page].

==Projects==
*Mining and blasting rocks

==Handling==
===Safety===
Gelignite is a powerful explosive and should be handled with care.

As it contains nitrate esters, skin contact will cause severe headaches.

===Storage===
Should be kept in a cool place, at constant temperature.

===Disposal===
Should be diluted with a proper solvent and carefully incinerated.

Alternatively, one can add it in lots of water in small bits and pour a diluted solution of NaOH to hydrolyze it.

==See also==
*[[Dynamite]]
*[[Smokeless powder]]

==References==
<references/>
===Relevant Sciencemadness threads===
*[http://www.sciencemadness.org/talk/viewthread.php?tid=949 nitroglycerin]
*[https://www.sciencemadness.org/whisper/viewthread.php?tid=22911 making plastic explosive from nitroglycerin]
*[http://www.sciencemadness.org/talk/viewthread.php?tid=3748 Underwater explosives]

[[Category:Materials with no specific chemical formula]]
[[Category:Pyrotechnics]]
[[Category:Energetic materials]]
[[Category:Energetic mixtures]]
[[Category:High explosives]]
[[Category:Things that can kill you very quickly]]
[[Category:Things that should NOT be messed with except by professionals]]
[[Category:Kewlism]]