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{{Short description|Pyrotechnical composition}}
'''Armstrong's mixture''' is a highly sensitive [[explosive material|primary explosive]]. Its primary ingredients are red [[phosphorus]] and strong oxidizer, such as [[potassium chlorate]] and [[potassium perchlorate]]. [[Sulfur]] is used to substitute for some or all of the phosphorus to slightly decrease sensitivity and lower costs; [[calcium carbonate]] may also be present in small proportions. Commercially, Armstrong's mixture is used in milligram quantities on the paper caps in toy [[cap gun]]s<ref name="calvert">{{cite web|url=http://www.du.edu/~jcalvert/phys/bang.htm |title=Flash! Bang! Whiz!: An introduction to propellants, explosives, pyrotechnics and fireworks |author=J. B. Calvert |accessdate=2006-11-11 |archiveurl=https://web.archive.org/web/20061115141121/http://www.du.edu/~jcalvert/phys/bang.htm |archivedate=15 November 2006 |deadurl=no }}</ref> and in [[party popper]]s.
'''Armstrong's mixture''' is a highly shock and friction sensitive<ref name="laska">{{Cite book |last1=Laska |first1=Paul R. |url=https://books.google.com/books?id=KOY1CgAAQBAJ&q=armstrong+mixture+ied&pg=PA74 |title=Bombs, IEDs, and Explosives: Identification, Investigation, and Disposal Techniques |date=10 August 2015 |publisher=CRC Press |isbn=9781498714501}}</ref> [[explosive material|explosive]]. Formulations vary, but one consists of 67% [[potassium chlorate]], 27% [[red phosphorus]], 3% [[sulfur]], and 3% [[calcium carbonate]].<ref name="calvert">{{cite web |author=J. B. Calvert |title=Flash! Bang! Whiz!: An introduction to propellants, explosives, pyrotechnics and fireworks |url=http://www.du.edu/~jcalvert/phys/bang.htm |url-status=dead |archiveurl=https://web.archive.org/web/20061115141121/http://www.du.edu/~jcalvert/phys/bang.htm |archivedate=15 November 2006 |accessdate=2006-11-11}}</ref><ref name="impact_crackers">{{cite web |author=John Donner |title=Impact Firecrackers |url=http://www.freeinfosociety.com/pdfs/science/impactfirecrackers.pdf#page=13 |url-status=dead |archive-url=https://web.archive.org/web/20070107050106/http://www.freeinfosociety.com/pdfs/science/impactfirecrackers.pdf#page=13 |archive-date=2007-01-07 |accessdate=2006-11-11 |page=13}}</ref> It is named for [[Sir William Armstrong]], who invented it sometime prior to 1872 for use in [[Explosive shell|explosive shells]].<ref>{{Cite book |last=Wagner |first=Johannes Rudolf |url=https://books.google.com/books?id=G0Q3AAAAMAAJ |title=A Handbook of Chemical Technology |date=1872 |publisher=J. & A. Churchill |pages=546 |language=en}}</ref>{{Additional citations needed|reason=It's possible armstrong never had anything to do with this and the name was a misnomer, I have to dig up my reference and will remove this when I do|date=October 2024}}


== Toys ==
It has also been considered a suitable mixture for the primer used in [[gun]]s after [[boron carbide]] has been added, that was used during the Second World War.<ref>{{US patent reference|number=3973502|y=1976|m=08|d=10|inventor=Charles R Olsen|title=Tube primer}}</ref
Armstrong's mixture can be used as ammunition for toy [[Cap gun|cap guns]]. The mixture is suspended in water with some [[gum arabic]] or similar binder and deposited in drops, each containing a few milligrams of explosive, to dry between layers of paper backing. The dots explode with some smoke when struck.<ref name="calvert" />


Armstrong's mixture can be used in impact [[Firecracker|firecrackers]] known as ''cap torpedoes'', which explode on impact when the ball (made of clay or [[papier-mâché]]) is thrown or (with some types) launched by [[slingshot]]. The firecrackers may include gravel with the explosive mixture to ensure enough friction is generated to produce a detonation.<ref name="impact_crackers" />
== Safety considerations ==

Because of its sensitivity to shock, friction and flame, Armstrong's mixture is an extremely dangerous explosive. Only about 10 mg of it is used per item of consumer fireworks. Depending on composition, conditions and quantity, Armstrong's mixture can explode violently in an enclosed space.<ref>{{cite web|url=http://www.freeinfosociety.com/pdfs/science/impactfirecrackers.pdf|title=Impact Firecrackers|author=John Donner|accessdate=2006-11-11|format=PDF}}</ref>
== Military use ==
With the addition of a grit such as [[boron carbide]] (in a modified formulation given as 70% KClO<sub>3</sub>, 19% red phosphorus, 3% sulfur, 3% chalk, and 5% boron carbide by weight), Armstrong's mixture has been considered for use in [[firearm]] [[Primer (firearms)|primers]].<ref name=":0">{{US patent reference|number=3973502|y=1976|m=08|d=10|inventor=Charles R Olsen|title=Tube primer}}</ref> This use as primer for artillery propellants may have been Armstrong's original purpose.<ref name="haarman">{{Cite journal |last=Haarmann |first=Donald J. |date=1985 |title=Ask The Wiz |url=https://yarchive.net/explosives/armstrongs_mixture.html |issue=51 |archive-url=https://web.archive.org/web/20010216060318/http://yarchive.net/explosives/armstrongs_mixture.html |archive-date=2001-02-16 |journal=American Fireworks News}}</ref>

It also was seen in various patents for matches, novelty fireworks, and signalling devices.<ref name="haarman" />

Armstrong's mixture has been used in thrown impact-detonated [[improvised explosive device]]s, made simply by loading it into hollow balls.<ref name="laska" />{{better citation needed|reason=The single available quote just describes the manufacture of one of the type of globe torpedo which doesn't scream "IED" given their low explosive content.|date=October 2024}}

== Safety ==
Armstrong's mixture is both very sensitive and very explosive, a dangerous combination that limits its practical use to toy caps.<ref name="kosanke">{{Cite journal |last1=Kosanke |first1=B. J. |last2=Kosanke |first2=K. L. |date=1996 |title=Explosive Limit of Armstrong's Mixture |url=http://www.jpyro2.com/wp-content/uploads/2012/08/Kos-346-347.pdf |url-status=live |journal=American Fireworks News |issue=177 |archive-url=https://web.archive.org/web/20190710174933/http://www.jpyro2.com/wp-content/uploads/2012/08/Kos-346-347.pdf |archive-date=2019-07-10 |access-date=2022-12-04}}</ref> Such toy caps and fireworks typically contain no more than 10 milligrams each, but gram quantities can cause maiming hand injuries.<ref>{{Cite web |date=2013-04-09 |title=The powerful, unstable explosive found in children's toys |url=https://gizmodo.com/the-powerful-unstable-explosive-found-in-childrens-to-471400286 |url-status=live |archive-url=https://web.archive.org/web/20210620195340/https://gizmodo.com/the-powerful-unstable-explosive-found-in-childrens-to-471400286 |archive-date=2021-06-20 |access-date=2022-12-04 |website=Gizmodo |language=en}}</ref>{{better source needed|reason=gizmodo is barely reliable for tech news, let alone this|date=October 2024}}

The mixture is likely to explode if mixed dry and is even dangerous wet. If the pH is not made neutral, phosphoric acids that may have been generated by oxidized phosphorus on contact with the water could cause it to deteriorate while slowly drying. Generally the wet slurry or paste is loaded into the final casing while wet and was heat-dried in rotating drums prior to being coated with [[sodium silicate|water glass]] to securely protect them from leakage when globe torpedos were still in production commercially.<ref name="tenney">{{Cite book |last=Davis |first=Tenney L. |url=http://archive.org/details/ChemistryOfPowderAndExplosives |title=Chemistry of Powder and Explosives |pages=105–106}}</ref><ref name="impact_crackers" /><ref name="kosanke" />

Simple mixtures of red phosphorus and potassium chlorate can detonate at a wide range of proportions; a 20% phosphorus mixture had 27% of the equivalent power of a like mass of [[TNT]] in a laboratory experiment, and the detonation of the 10% and 20% phosphorus mixtures even in small unconfined samples of 1 gram was described by the authors of one study as "impressive" and "scary".<ref name="kosanke" />

Pyrotechnician John Donner wrote in 1996 that it "is the most hazardous mixture commonly used in small fireworks."<ref name="impact_crackers" />

Davis Tenney called it "a combination which is the most sensitive, dangerous, and unpredictable of the many with which the pyrotechnist has to deal. Their preparation ought under no conditions to be attempted by an amateur."<ref name="tenney" />

Toy charges, such as the several-milligram dots used for cap guns, are individually harmless but potentially dangerous in large numbers.<ref name="calvert" /> On May 14, 1878, such an accident occurred in Paris. A store containing some six to eight million paper caps, totaling about 64 kilograms of explosive mass, caught fire and exploded, killing 14 and injuring 16 more.<ref name="haarman" />


== References ==
== References ==

Latest revision as of 01:23, 3 November 2024

Armstrong's mixture is a highly shock and friction sensitive[1] explosive. Formulations vary, but one consists of 67% potassium chlorate, 27% red phosphorus, 3% sulfur, and 3% calcium carbonate.[2][3] It is named for Sir William Armstrong, who invented it sometime prior to 1872 for use in explosive shells.[4][additional citation(s) needed]

Toys

[edit]

Armstrong's mixture can be used as ammunition for toy cap guns. The mixture is suspended in water with some gum arabic or similar binder and deposited in drops, each containing a few milligrams of explosive, to dry between layers of paper backing. The dots explode with some smoke when struck.[2]

Armstrong's mixture can be used in impact firecrackers known as cap torpedoes, which explode on impact when the ball (made of clay or papier-mâché) is thrown or (with some types) launched by slingshot. The firecrackers may include gravel with the explosive mixture to ensure enough friction is generated to produce a detonation.[3]

Military use

[edit]

With the addition of a grit such as boron carbide (in a modified formulation given as 70% KClO3, 19% red phosphorus, 3% sulfur, 3% chalk, and 5% boron carbide by weight), Armstrong's mixture has been considered for use in firearm primers.[5] This use as primer for artillery propellants may have been Armstrong's original purpose.[6]

It also was seen in various patents for matches, novelty fireworks, and signalling devices.[6]

Armstrong's mixture has been used in thrown impact-detonated improvised explosive devices, made simply by loading it into hollow balls.[1][better source needed]

Safety

[edit]

Armstrong's mixture is both very sensitive and very explosive, a dangerous combination that limits its practical use to toy caps.[7] Such toy caps and fireworks typically contain no more than 10 milligrams each, but gram quantities can cause maiming hand injuries.[8][better source needed]

The mixture is likely to explode if mixed dry and is even dangerous wet. If the pH is not made neutral, phosphoric acids that may have been generated by oxidized phosphorus on contact with the water could cause it to deteriorate while slowly drying. Generally the wet slurry or paste is loaded into the final casing while wet and was heat-dried in rotating drums prior to being coated with water glass to securely protect them from leakage when globe torpedos were still in production commercially.[9][3][7]

Simple mixtures of red phosphorus and potassium chlorate can detonate at a wide range of proportions; a 20% phosphorus mixture had 27% of the equivalent power of a like mass of TNT in a laboratory experiment, and the detonation of the 10% and 20% phosphorus mixtures even in small unconfined samples of 1 gram was described by the authors of one study as "impressive" and "scary".[7]

Pyrotechnician John Donner wrote in 1996 that it "is the most hazardous mixture commonly used in small fireworks."[3]

Davis Tenney called it "a combination which is the most sensitive, dangerous, and unpredictable of the many with which the pyrotechnist has to deal. Their preparation ought under no conditions to be attempted by an amateur."[9]

Toy charges, such as the several-milligram dots used for cap guns, are individually harmless but potentially dangerous in large numbers.[2] On May 14, 1878, such an accident occurred in Paris. A store containing some six to eight million paper caps, totaling about 64 kilograms of explosive mass, caught fire and exploded, killing 14 and injuring 16 more.[6]

References

[edit]
  1. ^ a b Laska, Paul R. (10 August 2015). Bombs, IEDs, and Explosives: Identification, Investigation, and Disposal Techniques. CRC Press. ISBN 9781498714501.
  2. ^ a b c J. B. Calvert. "Flash! Bang! Whiz!: An introduction to propellants, explosives, pyrotechnics and fireworks". Archived from the original on 15 November 2006. Retrieved 2006-11-11.
  3. ^ a b c d John Donner. "Impact Firecrackers" (PDF). p. 13. Archived from the original (PDF) on 2007-01-07. Retrieved 2006-11-11.
  4. ^ Wagner, Johannes Rudolf (1872). A Handbook of Chemical Technology. J. & A. Churchill. p. 546.
  5. ^ US patent 3973502, Charles R Olsen, "Tube primer", issued 1976-08-10 
  6. ^ a b c Haarmann, Donald J. (1985). "Ask The Wiz". American Fireworks News (51). Archived from the original on 2001-02-16.
  7. ^ a b c Kosanke, B. J.; Kosanke, K. L. (1996). "Explosive Limit of Armstrong's Mixture" (PDF). American Fireworks News (177). Archived (PDF) from the original on 2019-07-10. Retrieved 2022-12-04.
  8. ^ "The powerful, unstable explosive found in children's toys". Gizmodo. 2013-04-09. Archived from the original on 2021-06-20. Retrieved 2022-12-04.
  9. ^ a b Davis, Tenney L. Chemistry of Powder and Explosives. pp. 105–106.