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Spontaneous ignition of KNO3 Flash powder?


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#31 bigtonyicu

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Posted 04 September 2008 - 05:40 PM

I'm curiuos as to which Canadian code you are referring to here.


It's something I got when I went to take a course several years back (late 80s), I'll have to dig it out,
But it stated that every workbench used to handle lose powder should be:

Electrically conductive
Electrically Isolated (non conductive contact with the ground and walls)
And should be grounded directly to the earth

(I all honesty mine isn't isolated from the floor but it is a wooden floor and my static dissipative mat is grounded to the table)

#32 MDH

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Posted 05 September 2008 - 04:08 AM

Just stick to basic 5/3/2 Flash with boric acid... there's no need for the antimony.

#33 wjames

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Posted 05 September 2008 - 02:50 PM

on comparison, is 50:50 KN03:MG less sensitive to friction/static.....although i understand it to be less powerfull.

#34 Arthur Brown

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Posted 05 September 2008 - 05:33 PM

http://www.pyrosocie...amp;#entry47513

Is there any similarity with this?

Digger and Bigtonyicu are both skilled chemists so there is possibly a problem elsewhere
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#35 bigtonyicu

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Posted 05 September 2008 - 06:11 PM

Just stick to basic 5/3/2 Flash with boric acid... there's no need for the antimony.


Sb2S3 has a melting point of 550C

Al has a melting point of 660C



The and antimony trisulfide is Oxidized to Antimony pentoxide (Sb2O5) and the sulfur released helps reduce the aluminium oxide (Al2O3 melting 2054C) coating exposing elemental aluminium to react much faster with the KNO3, in a fully balance equation ( not the one I used, the fully balanced equation is much too powerful for my needs) this will speed up normal 5:3:2 flash by a factor of 2.5 times.



Antimony Trisulfide is a fairly common component of flash powders and has been use for many years in high power flash,… in very small insert the higher velocity is very useful; I need a more power full flash because I want to and many very small report to a 4 inch shell, so before you make statements like “It’s not needed” inform yourself on what the use is!!!

Digger and Bigtonyicu are both skilled chemists so there is possibly a problem elsewhere


Thank you

Speaking of Digger, I'd really appreciate his input on this thread

Edited by bigtonyicu, 05 September 2008 - 06:12 PM.


#36 Bonny

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Posted 05 September 2008 - 07:42 PM

Sb2S3 has a melting point of 550C

Al has a melting point of 660C



The and antimony trisulfide is Oxidized to Antimony pentoxide (Sb2O5) and the sulfur released helps reduce the aluminium oxide (Al2O3 melting 2054C) coating exposing elemental aluminium to react much faster with the KNO3, in a fully balance equation ( not the one I used, the fully balanced equation is much too powerful for my needs) this will speed up normal 5:3:2 flash by a factor of 2.5 times.



Antimony Trisulfide is a fairly common component of flash powders and has been use for many years in high power flash,… in very small insert the higher velocity is very useful; I need a more power full flash because I want to and many very small report to a 4 inch shell, so before you make statements like “It’s not needed” inform yourself on what the use is!!!



Thank you

Speaking of Digger, I'd really appreciate his input on this thread



Another very knowledgeable chemist is Mumbles...maybe he'll chime in here. One thing I might point out, although I'm sure you are aware, is that many comps don't perform best in fully balanced equation quantities...which is why ratios were "tweaked' by pyro practitioners...many who are also chemists.
Quick question bigtonyicu, why not make your own KClO4 as I'm sure you would be able to do w/o much difficulty...then you can simply make 70/30 etc...

#37 bigtonyicu

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Posted 05 September 2008 - 08:39 PM

Why not make your own KClO4 as I'm sure you would be able to do w/o much difficulty...then you can simply make 70/30 etc...


i'm having a very hard time finding a large platinum electrode!!!! I'm still looking I'd want a cell that can out put 0.5 to 1 lbs / day.


Lead dioxide anodes.

Lead nitrate is hard to get, so I'd have to make it, and well nitric acid is a pain to get also, could distill it from KNO3 and H2SO4 but That means a lot of glass wear I don't currently have.

#38 wjames

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Posted 05 September 2008 - 08:52 PM

i'm having a very hard time finding a large platinum electrode!!!! I'm still looking I'd want a cell that can out put 0.5 to 1 lbs / day.


shame you weren't in the uk......

i could sort that out for you !!!!

#39 Bonny

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Posted 05 September 2008 - 10:22 PM

i'm having a very hard time finding a large platinum electrode!!!! I'm still looking I'd want a cell that can out put 0.5 to 1 lbs / day.


Lead dioxide anodes.

Lead nitrate is hard to get, so I'd have to make it, and well nitric acid is a pain to get also, could distill it from KNO3 and H2SO4 but That means a lot of glass wear I don't currently have.



PM me if you want, I have (had anyway things are more of a PITA to find these days) a source for 70% nitric in Canada...expensive though. You can sometimes find it through hydroponic shops, maybe around 30% conc.

#40 Arthur Brown

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Posted 06 September 2008 - 08:42 AM

Looking at Bigtonyicu's ingredients, Nitrate and known Al powder are of known purity, but the lampblack and the Antimony sulphide are they a trade commodity to ISO9000 or better or bagged and sold by a mail order merchant.

Speak to Cabot in the states about the purity and specific impurities in lampblack. It's major use is in compounding conductive rubbers primarily used where dissipating static is needed. However it is made from petroleum and this can contain sulphur. A trace of Sulphur is almost insignificant in the rubber industry as they add sulphur to most curing systems. However free sulphur in a sensitive pyro mix is un healthy.

Does the Antimony sulphide have a purity specified. If it's a raw material (used in brake pads for cars I think) is it a suitable grade for pyro. A supplier to ISO9000 / 9001 should have access to the package history and what the analysis was. Sadly an ebay type vendor may not know 9000! :(

If There is a vein of rock Antimony sulphide somewhere that has some free sulphur even physically included, can we check for free sulphur, should we check for free sulphur? Is there a reliable test for free sulphur in a sulphide?


Static sources can be very localised, when I worked in a dark room (photo) I used to see static flashes from pulling masking tape off the reel. I've no intention to test every flash formulation for it's static ignition energy. OK its's a very specialised part of our field of interest, but has anyone seen or done tests with various diapering materials. Has anyone heard good evidence of good or bad materials for diapering sheets.
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#41 bigtonyicu

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Posted 06 September 2008 - 05:15 PM

Looking at Bigtonyicu's ingredients, Nitrate and known Al powder are of known purity, but the lampblack and the Antimony sulphide are they a trade commodity to ISO9000 or better or bagged and sold by a mail order merchant.

Speak to Cabot in the states about the purity and specific impurities in lampblack. It's major use is in compounding conductive rubbers primarily used where dissipating static is needed. However it is made from petroleum and this can contain sulphur. A trace of Sulphur is almost insignificant in the rubber industry as they add sulphur to most curing systems. However free sulphur in a sensitive pyro mix is un healthy.

Does the Antimony sulphide have a purity specified. If it's a raw material (used in brake pads for cars I think) is it a suitable grade for pyro. A supplier to ISO9000 / 9001 should have access to the package history and what the analysis was. Sadly an ebay type vendor may not know 9000! :(

If There is a vein of rock Antimony sulphide somewhere that has some free sulphur even physically included, can we check for free sulphur, should we check for free sulphur? Is there a reliable test for free sulphur in a sulphide?


Static sources can be very localised, when I worked in a dark room (photo) I used to see static flashes from pulling masking tape off the reel. I've no intention to test every flash formulation for it's static ignition energy. OK its's a very specialised part of our field of interest, but has anyone seen or done tests with various diapering materials. Has anyone heard good evidence of good or bad materials for diapering sheets.


Both Lampblack and Sb2S3 are reagent grades (>99.98% C) (>99.4% Sb2S3).

FYI lamp black is not conductive they use graphite for SD mats

and free sulfur is not a problem, even a fee % of the mix wouldn't throw anything off

#42 cooperman435

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Posted 07 September 2008 - 12:36 PM

Bigtonyicu lampblack can be conductive as thats its use in bridgless ematches. As with charcoal different products can be used to manufacture lampblack from and as far as I recall it is Acetylene lampblack is conductive.

#43 MDH

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Posted 09 September 2008 - 05:52 AM

Antimony Trisulfide is a fairly common component of flash powders and has been use for many years in high power flash,… in very small insert the higher velocity is very useful; I need a more power full flash because I want to and many very small report to a 4 inch shell, so before you make statements like “It’s not needed” inform yourself on what the use is!!!


The chinese used to break firecrackers with 5/3/2 so I don't think straight flash should yield anything less than flash with lampblack and antimony trisulfide.

#44 bigtonyicu

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Posted 09 September 2008 - 04:53 PM

The chinese used to break firecrackers with 5/3/2 so I don't think straight flash should yield anything less than flash with lampblack and antimony trisulfide.


FYI lampblack AKA soot... is what's contained in German/indian Dark aluminum, so basicly what you are saying is that there is no defference between 5 micron aluminum and 5 micron German ???




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