Chlorate vs Nitrate vs Perchlorate Flash?

[OblivionFall]

Hi there,

 

I am counting the 188 more days until Halloween this year. I am looking forward to using smoke flares, bengal flares, canister shells and of course some salutes.

I have researched Flash Powder safety and worked with Nitrate Flash for quite some time, and I'm looking to get some feedback on the level of safety with different oxodizers.

 

My main question is, with blue aluminum powder (so the Flash can't deflagrate out in the open) and salutes of 20g-30g of composition, how unsafe is it to use Potassium Chlorate as an oxodizer? I understand that Perchlorate should always be used but there's no way for me to get a hold of it. I understand the concern for using Chlorate as an oxodizer in Flash and it's incompatibilities.

 

I have talked to MWJ and other people about it on this forum. MWJ tested Chlorate with Aluminum powder suitable for flash (not blue aluminum) by smacking it with a hammer and said that it did not ignite on him. With blue aluminum powder, I would assume that this would not be a concern seeing as though blue aluminum flash can only deflagrate when contained properly. My only concern would be it going off when inside of the enclosure.

 

What is your guys' take on this?

 

Last year I explained my take on Flash Powder and how it would be a better idea to inform the individuals making it so they make it more safely rather than tell them not to here http://www.amateurpyro.com/forums/topic/10327-the-flash-powder-approach-or-why-the-community-has-to-distance-itself-more-emphatically-from-certain-practices/?hl=%2Bflash+%2Bsafety&do=findComment&comment=137023

Edited April 26, 2015 by OblivionFall

[FlaMtnBkr]

I would imagine chlorate and blue Al would be less sensitive than perchlorate and black/dark aluminum.

 

I would still try to use the binary method while screening the chlorate first to get out lumps and make it more free flowing.

 

I would also have any tools that are used with the chlorate well marked and separate from other tooling, especially if you ever use ammonium salts. I would also do it out away from anything so any spills go on the ground and sources of ignition are minimized.

[OblivionFall]

I would imagine chlorate and blue Al would be less sensitive than perchlorate and black/dark aluminum.

 

I would still try to use the binary method while screening the chlorate first to get out lumps and make it more free flowing.

 

I would also have any tools that are used with the chlorate well marked and separate from other tooling, especially if you ever use ammonium salts. I would also do it out away from anything so any spills go on the ground and sources of ignition are minimized.

Thanks for the feedback. I'm going to get new funnels/plastic containers to hold the chemicals in because I made a lot of KNO3/S/Al Flash last year.

[LiamPyro]

I have heard of some people having storage issues will chlorate flash, where it's performance diminished greatly after only a week or two. I believe they were using home-synthesized KCIO3 (chloride impurities?), aluminum, and agricultural-grade sulfur that supposedly contained an acid neutralizer. They also said they had a similar problem with their chlorate stars, so it was probably just impurities in the KCIO3 causing the problems.

[OblivionFall]

I have heard of some people having storage issues will chlorate flash, where it's performance diminished greatly after only a week or two. I believe they were using home-synthesized KCIO3 (chloride impurities?), aluminum, and agricultural-grade sulfur that supposedly contained an acid neutralizer. They also said they had a similar problem with their chlorate stars, so it was probably just impurities in the KCIO3 causing the problems.

That makes sense. Homemade chlorate is what I'm working with, so that may be an issue. I'll have to test it out.

[LiamPyro]

I know that chloride contamination would be no good, as it corrodes aluminum. I'm not sure what other issues contaminants can cause, but it would certainly be a good idea to look into it.

[MWJ]

So, how much more sensitive is Kclo3 FP compared to Kclo4 FP?

[LiamPyro]

On the topic of KClO3 flash, I was testing my very limited knowledge of stoichiemetry and chemical reactions by attempting to figure out one of the theoretically ideal proportions for KClO3/Al/S. My end result was 490.2/107.92/96.21 KClO3/Al/S, or roughly 50/10/10. Is this correct? Or are the end products of the reaction unrealistic? I wasn't sure if the KCl would stay bonded or would separate to form compounds with the Al or S. Here are my calculations:

 

4 KClO3 + 4 Al + 3 S --> 4 KCl + 2 Al2O3 + 3 SO2 4 moles KCIO3 = 490.2 grams 4 moles Al = 107.92 grams 3 moles S = 96.21

[schroedinger]

Liam even if your stochiometric looks good on the first view, i stopped checking it before the reaction arrow. Relly KClO3 + S flash? I heard of strange ideas before before but this is a call for a coffin. Edited April 29, 2015 by schroedinger

[LiamPyro]

Liam even if your stochiometric looks good on the first view, i stopped checking it before the reaction arrow. Relly KClO3 + S flash? I heard of strange ideas before before but this is a call for a coffin.

LOL! It's an equation, and is not meant to be done in real life. I already know the stoichiemetric ratios for KCIO4/Al and KCIO3/Al, so I figured I'd try adding some sulfur. I should've picked a better example it looks like.

[Shunt]

I am no chemest, but I do my research, and KClO3 + S Is a comp that has been proven time and time again to be unsafe. There are much better alternatives.

[LiamPyro]

I am no chemest, but I do my research, and KClO3 + S Is a comp that has been proven time and time again to be unsafe. There are much better alternatives.

Indeed it is, although I don't believe it is nearly as bad as people make it out to be. Spontaneous combustion would'nt be a concern unless acidic sulfur was used, although adding a few percent of a basic material such as CaCO3, SrCO3, etc would always be a good idea. It is quite sensitive to friction/impact though, I have done a project from Sylighter where a wet paste of KCIO3/S with some dextrin and powdered glass is applied to round stones, and they are thrown to make a bang when dry. Also, I noticed something peculiar a while back when I mixed a *small* amount of KCIO3/S, folded it between a piece of tape, and whacked it with a hammer on concrete. It made a sharp bang, but when burned in the open was as sluggish as BP fountain mix. Also, not all of it went off in the hammer test. These observations lead me to believe it detonated. I wonder if this is the case?

[mabuse00]

Concerning chlorate flash, IMHO this is not unreasonable per se. As long as it's really only chlorate and aluminium and safety rules are applied.

 

 

 

I have heard of some people having storage issues will chlorate flash, where it's performance diminished greatly after only a week or two. I believe they were using home-synthesized KCIO3 (chloride impurities?), aluminum, and agricultural-grade sulfur that supposedly contained an acid neutralizer. They also said they had a similar problem with their chlorate stars, so it was probably just impurities in the KCIO3 causing the problems.

That is a very interesting issue, especially for europeans like me who won't have easy acces to chlorates and perchlorates in future. Let's forget that sulphur thing, in 99% of typical applications sulphur does not bring any advantage.

 

But how about the chloride?

 

If you set up your own little production, the effort to produce high grade perchlorate is huge, so it's obvious to substitute it with chlorate whenever possible.

That homemade chlorate has usually much more chloride in it than commercial stuff is a fact, nobody is keen to give up a large percentage of his chlorate in the process of getting rid of the last few percent chloride...

 

When I used up my last batch of homemade chlorate I made salute rockets a few days before new years eve, everything was dry and used up rather quickly.

 

 

What bothers me is the possible use in stars, and I don't mean the typical classic chlorate/shellac/carbonate/binder formulations but rather something magnalium fueled. I wonder if this is possible in practice? Did anybody ever try it?

KCl has a critical relative humidity of 85%. I've used sodium nitrate (75%) during the winter and had no troubles. So depending on climate KCl would not necessaryly draw water.

No water around - no corossion. Non aqueuos binder and go for it......?

 

I will test this in practice sometime...

[schroedinger]

Mabuse as long as we are talking about pottasium chlorate, the loss of chlorate close to zero during recristallisation.

After first recristallisation cicle (tab water) the normally i end up with 0.3 -1.2 g of Chloride per kg chlorat (measured by titration against silver nitrate) and after a second recristallisation it using distilled water the concentration is less then 0.1 g/kg.

Both are no numbers i would worry about the contamination. Just make sure you dissolve all your crystalls fully during heating process and cool down slowly (just turn of the hot plate and let it stand, if you need to filter your solution, do so and reboil.), you want the biggest cristals you can get (mostly flakes from 0.3 to 1.2 cm diameter).

[henfanya6]

chlorate is much more sensitive ,care when handle with that

[greenlight]

Even though the poster said he was not making chlorate flash with sulphur, I just wanted to add some info..

 

There is no point having the sulphur in that chlorate flash comp for two reasons, one being the obvious sensitivity hazard when the two are mixed.

 

Secondly, sulphur is usually incorporated into pyrotechnic compositions to lower the ignition temperature and make for easier ignitability.

 

Potassium chlorate has quite a low melting point with fuels already and is one of the only pyro oxidizers (barium chlorate too) that has an exothermic decomposition. Most oxidizers require only heat input for their decomposition but potassium chlorate actually releases extra heat when it decomposes to KCl and O2 and contributes energy.

 

So there is no point adding a lower melting fuel to make initiation even easier with chlorate flash. The stuffs going to ignite with a fuse without the sulphur anyway, why make it even more prone to ignition.

 

With potassium chlorate's negative heat of reaction value it already makes compositions require minimal energy for initiation.

I think this one main factor that contributes to it being known as a more dangerous oxidizer than perchlorate for example as well as its instability with some fuels.

 

I will see if I can find any recorded ignition temps.

Edited September 23, 2018 by greenlight