Chinese White Strobe with Bismuth Trioxide

[rellim]

I found a Russian video on Youtube demonstrating this strobe formulation:

 

Ba(NO₃)₂ 68 AlMg .26 Bi₂O₃ 3 Binder 3

 

I made a few sample stars with -200 + 320 MgAl and it does indeed give brilliant white flashes. Does anyone know what the effect of Bismuth Trioxide is with this formulation? Could it be effectively added to other strobe compositions?

 

Video at

 

[Merlin]

I'm clueless. That sure is a vigorous strobe. I'm sure Mumbles or Lloyd will know.

[dynomike1]

Dam that beats mine

[NeighborJ]

I'm gonna need to try that formula, maybe with some HCB for green. I wonder what binder? NC? Dex? I can't read russian.

[PhoenixRising]

Just translated связka to "bond".

 

At 3 percent it is most likely not dextrin.

 

NC would likely work just fine. PVB would most likely work as well.

 

Gum Arabic would work at 3 percent as well.

 

If phenolic were used (which it doesn't work for all formulas) I'd use at least 4 or 5 percent, any less is too weak IMO.

 

I would not use Red Gum in such a small amount.

 

Most likely not Starpol (does anyone even use that stuff anymore?)

 

If you use NC but don't have the powder form it may be difficult to roll them, so cutting an acetone patty similar to big crackle stars might suffice.

 

All that Barium and Metal may require a decent prime too, so take that into account.

Edited August 13, 2018 by PhoenixRising

[sora]

Just for the records, a Pb-Nit based strobe:

https://www.youtube.com/watch?v=ds7StW330fc

[Adrenaline]

There are also reports of colored bismuth trioxide strobes on youtube. Have a look at this NeighborJ, maybe you can save that HCB for other applications.

 

https://www.youtube.com/watch?v=b7i94g9ZJAs

 

I've had these compositions on my list for a few months now, never got around to test them so I don't know how well they work.

[kingkama]

It is the chlorate one?

[rellim]

A confusing comment by the author says: dextrin - 3% (wallpaper glue)

I used 3% dextrin and the stars were not especially sturdy.

[NeighborJ]

Hmm? Strobe stars are generally made quite small. A blend of dex and CMC(wallpaper glue) would likely be enough. Wheat past should also work.

 

Adrenaline, that strobe looked more like a lithium pink than a red. Do you have the formula to post or a link to a thred?

[Mumbles]

With good quality dextrin, 3% will do the trick for binding. If you're making it in your own oven, it might not be quite up to task.

 

I too am stumped as to bismuth trioxide's use here. Best guess, and also wild ass guess, it's a burn rate catalyst and speeds up the effect. Whistle and strobe comps are more similar than one may thing. It's not particularly effective for whistle rockets as per Danny Creagan's testing, but maybe barium nitrate or metal based compositions are another ball game.

 

Nitrate strobes are more strange than AP/sulfate strobes. I haven't seen many without sulfur as a major component. Has anyone tried to reproduce these stars?

[Crazy Swede]

Maybe the barium nitrate and magnesium part of the magnalium smolders during the dark phase and the bismuth trioxide and the aluminum part of the magnalium creates the flashes through a thermitic reaction?

 

I doubt this system would lend itself to create green colored strobe with the addition of chlorine donors since bismuth usually gives a yellow color to the flame.

[Adrenaline]

Hmm? Strobe stars are generally made quite small. A blend of dex and CMC(wallpaper glue) would likely be enough. Wheat past should also work.

 

Adrenaline, that strobe looked more like a lithium pink than a red. Do you have the formula to post or a link to a thred?

 

The (alleged) formula is in the video description:

Sr(NO3)2 - 75%, Bi2O3 - 5%, AlMg - 20%, PVC - up to 5% (over 100%).

 

I'm sure that these strobes have been mentioned on APC before, but I can't seem to find the thread.

[dynomike1]

Looks like you could use any binder but not phenolic resin

[Yus]

See here.

https://www.amateurpyro.com/forums/topic/5476-strobe-stars/?p=175900

[Adrenaline]

Yes that's the thread! Thank you Yus.

Am I right in assuming that you discovered/reverse engineered this composition?

 

What partical size MgAl did you use in the red strobe?

[Yus]

At the beginning I have found Bi2O3 in chinese patent and then it was confirmed by chemical analysis (SEM, XRD) in the commercial stars.

Al-Mg can be mixture between 100 and 250 mesh.

 

http://s010.radikal.ru/i314/1711/59/3417ed2906fb.png

 

http://s019.radikal.ru/i617/1711/59/dcef7d4d3da5.png

 

https://www.google.com/patents/CN103601604B?cl=en

 

Prime 1: Ba(NO₃)₂ - 27%, KClO₄ - 33%, AlMg - 7%, S - 10%, C - 13%, binder - 10%.

 

Prime 2: KNO₃ - 60%, AlMg - 10%, S - 10%, C - 15%, binder - 5%.

 

Prime 1 and 2 should be corrected experimentally.

[Mumbles]

Maybe the barium nitrate and magnesium part of the magnalium smolders during the dark phase and the bismuth trioxide and the aluminum part of the magnalium creates the flashes through a thermitic reaction?

 

I doubt this system would lend itself to create green colored strobe with the addition of chlorine donors since bismuth usually gives a yellow color to the flame.

 

Maybe I've always been thinking too glitter focused. My general thinking has always been the dark phase is build up of barium sulfate or a sulfide species, and the flash phase is the reaction with the metal. It's been known that barium and strontium nitrate burn "vibrationally" with MgAl. I could see the Mg reacting differently than the Al. MgAl glitters have always been more attractive to me, being a little more shimmery. I like your thinking, and it could have merit.

 

Bismuth has it's own interesting effects. Bi(I) is only meta stable at higher temperatures, so maybe it is involved too. It's one of the things I've always kind of wondered about and thought about based on the applications in crackle. It is something that could be considered a dark strobe that gives off more sound than visible light. MgAl glitters and some effects like Fireflies on Cocaine/Flaming Shit Falls on You are certainly more sizzley and audible as well. It is something to ponder.

 

Thank you Yus for that thread. Russia has been putting out a lot of interesting things. Off hand, do you know if they're using the typical 50:50 MgAl that many people are accustomed to?

[Yus]

I am not from Russia. I am from Ukraine!

Commercial and homemade Al-Mg (1:1) are "chemically" same.

They always contain brittle intermetallic phase, namely, Mg17Al12 (see phase diagram). It melts at 460'C.

Edited August 16, 2018 by Yus

[kingkama]

I wondering if the 3% of bismute can be substitued by the same amouth of lead trioxide

[rellim]

Red and white strobe formulas have very different oxygen balances. Red is greatly over oxidized while white has a small oxygen surplus..

Edited August 16, 2018 by rellim

[Volas]

I wondering if the 3% of bismute can be substitued by the same amouth of lead trioxide

No, it does not work in such a formula. These are not dragon eggs.

[Mumbles]

Volas, do you know what purpose the bismuth serves?

[kingkama]

I think It Will works,if works for Dragon egg Will works for this strobe, Dragon egg are like strobe a smoldering phase and a flash phase, the issue May be the colour output.This composition was made to avoid the bad smell of the full sulfur nitrate White strobe (that it's specified in the patent) using the bismute properties to reproduce the sulfur phased Burning. Obviusly the Will not use Pb because it's proibited in a lot of country, but chemically It Will works?

[Mumbles]

Do you have a reference to the patent you're referring to?