827:
due to change in the environment, or to other unknowable factors in either the original manufacturing or in real-world storage. Additionally, accidental contaminants such as strong acids or sulfur compounds can sensitise them even more. Because flash powder mixtures are so easy to initiate, there is potentially a high risk of accidental explosions which can inflict severe blast/fragmentation injuries, e.g. blindness, explosive amputation, permanent maiming, or disfigurement. Fatalities have occurred. The various flash powder compositions should therefore not be handled by anyone who is unfamiliar with their properties, or the handling techniques required to maintain safety. Flash powder and flash powder devices pose exceptionally high risks to children, who typically cannot understand the danger and may be less adept with safe handling techniques. As a result, children tend to suffer more severe injuries than adults.
620:, in which the materials are poured separately onto a large piece of paper, which is then alternately lifted at each corner to roll the composition over itself and mix the components. Some amateur pyrotechnicians choose to mix the composition by shaking in a closed paper container, as this is much quicker and more effective than diapering. One method of mixing flash is to put the components in the final device and handling the device will mix the flash powder. Paper/cardboard is chosen over other materials, such as plastic, as a result of its favorable
66:
230:
168:
25:
356:
782:. Its extremely low cost makes it popular among manufacturers of low-grade fireworks in China. Like all mixtures containing chlorates, it is extremely sensitive to friction, impact and electrostatic discharge, and is considered unsafe in pyrotechnic devices that contain more than a few tens of milligrams of the mixture.
723:
For photographic use, mixtures containing magnesium and nitrates are made much more fuel rich. The excess magnesium is volatilized by the reaction and burns in air providing additional light. In addition, the higher concentration of fuel results in a slower burn, providing more of a "poof" and less
719:
to two parts Mg is close to ideal and provides the most rapid burn. The magnesium powder should be smaller than 200 mesh, though up to 100 mesh will work. The potassium nitrate should be impalpable dust. This mixture is popular in amateur pyrotechnics because it is insensitive and relatively safe as
511:
This composition, usually in a ratio of 5 parts potassium nitrate, to 3 parts aluminum powder, to 2 parts sulfur, is especially popular with hobbyists. It is not very quick-burning unless exceptionally fine ingredients are used. Although it incorporates sulfur, it is in fact fairly stable, sustaining
450:
is unstable, and a poor choice for flash powder that is to be stored for more than a very short period. For that reason, it has been largely replaced by the potassium perchlorate mixtures. Chlorate mixes are still used when cost is the overriding concern because potassium chlorate is less expensive
433:
Normally, flash powder mixtures are compounded to achieve a particular purpose. These mixtures range from extremely fast-burning mixtures designed to produce a maximum audio report, to mixtures designed to burn slowly and provide large amounts of illumination, to mixtures that were formerly used in
857:
Flash powder of any formulation should not be mixed in large quantities by amateur pyrotechnicians. Beginners should start with sub-gram quantities, and refrain from making large devices. Flash powder should only be made at the site at which it will be used. Additionally, the mixture should be made
853:
Some flash powder formulations (those that use single-digit micrometre flake aluminium powder or fine magnesium powder as their fuel) can self-confine and explode in small quantities. This makes flash powder dangerous to handle, as it can cause severe hearing damage and amputation injury even when
826:
Flash powders even within intended usages often release explosive force of deadly capacity. Nearly all widely used flash powder mixtures are sensitive to shock, friction and electrostatic discharge. In certain mixtures, it is not uncommon for this sensitivity to spontaneously change over time, or
736:
Magnesium based compositions degrade over long periods, meaning the metallic Mg will slowly react with atmospheric oxygen and moisture. In military pyrotechnics involving magnesium fuels, external oxygen can be excluded by using hermetically sealed canisters. Commercial photographic flash powders
728:
for a stoichiometry of nine parts fuel to one part oxidizer. Modern recreations of photographic flash powders may avoid the use of barium salts because of their toxic nature. A mixture of five parts 80 mesh magnesium to one part of potassium nitrate provides a good white flash without being too
627:
Large quantities should never be mixed in a single batch, as they are difficult to handle safely and can put bystanders at risk. In the event of accidental ignition, debris from a multiple-pound flash powder explosion can be thrown hundreds of feet with sufficient force to kill or injure. (Note:
608:
should be in powder form, free from clumps. It can be sieved through a screen, if necessary, to remove any clumps prior to use. The particle size of the perchlorate is not as critical as that of the aluminium component, as much less energy is required to decompose the
854:
sitting in the open. Self-confinement occurs when the mass of the pile provides sufficient inertia to allow high pressure to build within it as the mixture reacts. This is referred to as 'inertial confinement', and it is not to be confused with a detonation.
512:
multiple hits from a hammer onto a hard surface. Adding 2% of its weight with boric acid is reputed to significantly increase stability and shelf life, through resistance to dampening through ambient humidity. Other ratios such as 6 KNO
858:
immediately before use. When mixed, the transportation, storage, usage, various possession, and illegal "firearms" laws (including felonies) may come into effect that do not apply to the unmixed or pre-assembled components.
663:
metal have been used as photographic flash powders almost since the invention of photography. Potassium nitrate/magnesium flash powder should be mixed and used immediately and not stored due to its tendency of self-ignition.
850:. These mixtures are especially shock and friction sensitive and in many applications should be considered unpredictable. Modern pyrotechnic practices call for never using sulfur in a mix containing chlorate salts.
409:
is a yellow-tan dust-like powder historically used as a flash powder. Today, the principal use of the powder is to create flashes or flames that are large and impressive but relatively easy to manage safely in
600:
The stoichiometric ratio is 34.2% aluminum and 65.8% perchlorate by mass. A ratio of seven parts potassium perchlorate to three parts dark pyro aluminium is the composition used by most pyrotechnicians.
578:
are the only two components of the pyrotechnic industry standard flash powder. It provides a great balance of stability and power, and is the composition used in most commercial exploding fireworks.
499:. However this gives the problem with acid production and instability and so these mixtures are generally considered too unstable to be stored and must be mixed immediately before use.
745:
A flash composition designed specifically to generate flares that are exceptionally bright in the infrared portion of the spectrum use a mixture of pyro-grade magnesium and powdered
667:
If magnesium is not a very fine powder, it can be passivated with linseed oil or potassium dichromate. The passivated magnesium flash powder is stable and generally safe to store.
489:; any acid in the mixture makes it unstable. Sometimes a few percent of bicarbonate or carbonate buffer is added to the mixture to ensure the absence of acidic impurities.
631:
No matter the quantity, care must always be taken to prevent any electrostatic discharge or friction during mixing or handling, as these may cause accidental ignition.
604:
For best results, the aluminium powder should be "Dark Pyro" grade, with a flake particle shape, and a particle size of fewer than 10 micrometres. The KClO
390:
Flash powder compositions are also used in military pyrotechnics when production of large amount of noise, light, or infrared radiation is required, e.g.,
481:
It is considered critically important to exclude sulfur and any acidic components from these mixtures. Sulfur oxidises and absorbs moisture to produce
616:
Although this composition is fairly insensitive, it should be treated with care and respect. Hobbyist pyrotechnicians usually use a method called
715:
Mixtures designed to make reports are substantially different from mixtures designed for illumination. A stoichiometric ratio of three parts KNO
778:
This mixture, and similar mixtures sometimes containing pyro aluminium have been used since the early 1900s for small "Black Cat" style paper
240:
691: : 37.5% Mg by weight for the reactants of the above stoichiometrically balanced equation. Below is the same reaction but involving
993:
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316:, which burns quickly (deflagrates) and produces a loud noise regardless of confinement. It is widely used in theatrical
102:
193:
109:
838:. A spark of as little as 0.1–10 millijoules can set off certain mixtures. Certain formulations prominent in the
189:
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116:
746:
305:
391:
98:
867:
575:
372:
325:
628:
3 grams of mixture is enough to explode in open air without constraint other than air pressure.)
749:. These flares are used as decoys from aircraft that might be subject to heat-seeking missile fire.
988:
500:
345:
872:
847:
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447:
384:
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520:/2 Al/3 S also exist and work. All ratios have similar burn times and strength, although 5 KNO
496:
478: : 30% Al by weight for the reactants of the above stoichiometrically balanced equation.
406:
44:
998:
724:
of a "bang" when ignited. A formula from 1917 specifies 5 parts of magnesium to 6 parts of
443:
411:
376:
333:
562:
For best results, "German Dark" aluminum should be used, with air float sulfur, and finely
422:
371:
Different varieties of flash powder are made from different compositions; most common are
123:
814:
This mixture is not highly energetic, and in at least some parts of the United States,
725:
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than is needed to melt the aluminium into the liquid state required for the reaction.
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pure potassium nitrate. The finished mixture should never be ball milled together.
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is deliberately added as a third component to this mixture in order to reduce the
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779:
383:
is included in the mixture to increase the sensitivity. Early formulations used
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329:
65:
818:
containing 50 mg or less of this mixture are legal as consumer fireworks.
730:
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563:
454:
The simplest is a two-component chlorate mix, although this is rarely used.
321:
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877:
831:
656:
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555: : 31.6% Al : 9.4% S by weight for the reactants of the above
419:
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are sold as two-part mixtures, to be combined immediately before use.
843:
492:
380:
196:. Statements consisting only of original research should be removed.
354:
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834:—are often highly sensitive to friction, heat/flame and
503:
may be used as an alternative, and is more stable in storage.
359:
Examples of theatrical binary flash powders. Note the shared
223:
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59:
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729:
violent. Fuel rich flash powders are also used in theatrical
639:
Another flash composition common among amateurs consists of
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909:
Photographic Times and
American Photographer, vol.18
90:. Unsourced material may be challenged and removed.
912:. Scovill Manufacturing Company. 1888. p. 26
647:. Other metal nitrates have been used, including
830:Flash powders—especially those that use
8:
581:The balanced equation for the reaction is:-
53:Learn how and when to remove these messages
474:The composition is approximately 70% KClO
289:Learn how and when to remove this message
212:Learn how and when to remove this message
150:Learn how and when to remove this message
551:The composition is approximately 59% KNO
899:
507:Potassium nitrate, aluminium and sulfur
241:instructions, advice, or how-to content
972:, Vol. 54, 1917, Philadelphia, p. 384
7:
88:adding citations to reliable sources
970:The Photographic Journal of America
250:so that it is more encyclopedic or
387:instead of potassium perchlorate.
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34:This article has multiple issues.
774:Antimony trisulfide and chlorate
524:/3 Al/2 S seems to be dominant.
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75:needs additional citations for
42:or discuss these issues on the
655:nitrates. Compositions using
1:
363:(A) powder for some types of
344:shots) and was once used for
687:The composition is 62.5% KNO
192:the claims made and adding
1017:
570:Aluminium and perchlorate
994:Pyrotechnic compositions
747:polytetrafluoroethylene
306:pyrotechnic composition
438:Aluminium and chlorate
368:
957:Flash powder mixtures
868:Pyrotechnic initiator
635:Magnesium and nitrate
589:+ 8 Al → 3 KCl + 4 Al
576:potassium perchlorate
574:Aluminium powder and
373:potassium perchlorate
358:
451:than perchlorate.
392:missile decoy flares
84:improve this article
822:Safety and handling
559:balanced equation.
516:/3 Al/1 S and 5 KNO
501:Antimony trisulfide
442:The combination of
248:rewrite the content
16:Pyrotechnic mixture
873:Sprengel explosive
848:potassium chlorate
836:static electricity
741:Magnesium and PTFE
557:stoichiometrically
448:potassium chlorate
385:potassium chlorate
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177:possibly contains
888:Lycopodium powder
840:underground press
645:potassium nitrate
497:activation energy
407:Lycopodium powder
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707:+ 5 Mg → BaO + N
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434:photography.
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414:acts and for
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396:stun grenades
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272:November 2013
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202:November 2013
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73:This article
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914:. Retrieved
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883:Black powder
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816:firecrackers
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780:firecrackers
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338:firecrackers
330:cherry bombs
318:pyrotechnics
302:Flash powder
301:
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246:Please help
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82:Please help
77:verification
74:
50:
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37:
36:Please help
33:
643:powder and
564:ball milled
462:+ 2Al → Al
350:photography
256:Wikiversity
989:Explosives
983:Categories
916:23 October
894:References
753:2n Mg + (C
731:flash pots
675:+ 5 Mg → K
420:theatrical
264:Wikivoyage
186:improve it
110:newspapers
39:improve it
968:Watkins,
661:magnesium
653:strontium
641:magnesium
618:diapering
322:fireworks
260:Wikibooks
239:contains
190:verifying
45:talk page
939:PyroData
878:Thermite
862:See also
832:chlorate
765:→ 2n MgF
483:sulfuric
429:Mixtures
361:oxidizer
328:, e.g.,
324:(namely
310:oxidizer
999:Powders
810:+ 3 KCl
711:+ 5 MgO
683:+ 5 MgO
657:nitrate
402:History
346:flashes
342:cap gun
326:salutes
184:Please
124:scholar
844:sulfur
806:+ 3 SO
786:3 KClO
649:barium
585:3 KClO
540:+ 2 Al
493:Sulfur
416:cinema
381:sulfur
340:, and
254:it to
126:
119:
112:
105:
97:
699:Ba(NO
679:O + N
671:2 KNO
536:S + N
528:2 KNO
470:+ KCl
412:magic
365:fuels
334:M-80s
304:is a
262:, or
131:JSTOR
117:books
918:2017
846:and
798:→ Sb
790:+ Sb
659:and
651:and
609:KClO
485:and
458:KClO
446:and
418:and
394:and
375:and
367:(B).
320:and
314:fuel
252:move
103:news
348:in
188:by
86:by
985::
947:^
937:.
926:^
761:))
733:.
695:.
425:.
398:.
352:.
336:,
332:,
258:,
48:.
941:.
920:.
808:2
804:3
802:O
800:2
796:3
794:S
792:2
788:3
767:2
763:n
759:4
757:F
755:2
717:3
709:2
705:2
703:)
701:3
689:3
681:2
677:2
673:3
611:4
606:4
595:3
593:O
591:2
587:4
553:3
546:3
544:O
542:2
538:2
534:2
530:3
522:3
518:3
514:3
476:3
468:3
466:O
464:2
460:3
292:)
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200:(
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147:(
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114:·
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51:(
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