Water gel explosive
A water-gel explosive is a fuel sensitized
Water-gel explosives have almost completely displaced dynamite,[citation needed] becoming the most-used civil blasting agents.
Composition
Water gels usually have many different ingredients. They contain a gelatinizing agent, also known as a thickener, that modifies their consistency, ranging from easily pourable gels to hard solids. Polyvinyl alcohol, guar gum, dextran gums, and urea-formaldehyde resins are the typical gelling agents. Guar, specifically, is a gelling agent used for the aqueous portion of the water gel explosives.[3] The primary component of water gels is methylamine nitrate. Methylamine nitrate is the salt formed by the neutralization of methylamine with nitric acid.[4] Water gel explosives are also made of ammonium nitrate, calcium nitrate, aluminum, ethylene glycol and TNT. The proportions of these components vary depending on the desired explosiveness of the water gel.[5]
Preparation
Water gel explosives are produced by combining nitroparaffins, usually nitromethane, with an aqueous salt solution and a gelling agent. These nitroparaffins typically make up most of the water gel explosive. Different types of gelling agents are used to create the water gel explosive. One agent is insoluble in water, but able to gel with nitromethane. The gel used for nitromethane is cyanoethylether, a derivative of galactomannan gum. Other agents are water-soluble and are used for the aqueous salt solution. As referenced in the first paragraph, water-soluble gums and gel modifiers like guar can be used for the gelling of aqueous solutions. When the salt solution and nitroparaffin are gelled, the entire mixture is combined and mixed together until the desired consistency is achieved. One characteristic that allows the explosive to work so well is the insoluble nature of the nitroparaffin. The effectiveness of the water gels is dependent on the dissemination of salts in the salt solution. The particles need to be very small and fine so that they can be dispersed well throughout the solution. Some salts that are commonly used include: ammonium nitrate, sodium nitrate, sodium perchlorate and potassium chlorate. The sensitivity of the explosive must be increased in order to improve the initiation of the detonation of the explosive. There are different techniques for increasing the sensitivity. Aluminum or other powdered metals can help increase the sensitivity of the water gel, but increasing the sensitivity also means that the explosives are more combustible.[6] Powdered metals have not proven to be completely effective in increasing the sensitivity of the explosive because they do not uniformly mix through the solution. They also lose sensitivity as storage time increases. Liquid non-self-explosive sensitizers like nitrobenzene and liquid nitrotoluene have not worked well either because they are difficult to hold in suspension. Liquid aliphatic mononitrates have been found to work very effectively as sensitizers when they are well mixed in the water gel.[7]
Advantages and uses
Water gel explosives tend to be less
Water gel explosives are frequently used as
References
- ^ Cook, Melvin A. The Science of Industrial Explosives. (c)1974, page 14.
- ^ "Securesearch Inc - Realistic Inert Explosives Products, Inert IED Training Aids, Exact Replica Ordnances, Anti-Terrorism Awareness Products, IED Posters, Anti-Personnel Mines and Bomb Training Products for Military, Law Enforcement and Security Agencies :: Water Gel Explosives—Inert Simulants".
- ^ "WATER GEL EXPLOSIVE (EDUCATIONAL)". www.freewebs.com. Archived from the original on 2014-03-11.
- ^ "Water Gel Explosives". Archived from the original on 2013-04-09. Retrieved 2013-04-20.
- ^ "Chemistry". 18 December 2007.
- ^ "WATER GEL EXPLOSIVE (EDUCATIONAL)". www.freewebs.com. Archived from the original on 2014-03-11.
- ^ http://www.skk-banjaluckapivara.com/invent/stationary_exercise_bicycle/slurry_explosive_composition.html [dead link]
- ^ Explomo Tovex Brochure
- ^ "Water Gel Explosives". Archived from the original on 2013-04-09. Retrieved 2013-04-20.
- ^ "Toxic Fume Comparison of a Few Explosives Used in Trench Blasting" (PDF). www.cdc.gov. Retrieved 2018-12-08.