51 replies to this topic

[Chemguy]

Hi guys, I found some thing on the internet saying you could make a very fast burning powder that explodes in large proportions (but that is not what I would use it for.) It is KNO3:K2CO3:S in proportions 75:15:10. It said it burnt very fast, like very good BP. So I whipped up a batch of about 20g, and lit some, it was a very fine powder. It burnt very slowly, and ended up just being some burning sulfur. Does anyone know anything about this. Is it even true, and would it have any pyrotechnical uses that exceed the performance of BP or flash?
thanks.



[edit] Editted the title to more accuratly represent what's going on here. Fulminating powder is a high explosive.

Edited by Mumbles, 01 November 2006 - 11:11 PM.

[styropyro]

Someone correct me if I am wrong but that sounds like yellow powder. Yellow powder's true formula is a 3:2:1 ratio of Potassium Nitrate, Potassium Carbonate, and Sulfur. But to make it good you have to melt it together which is an extemely dangerous thing to attempt. But one cool thing about yellow powder is that it burns with almost no visible flame.

Edit: I found a thread called yellow powder in the newbie section. Here is a video of some burning

[pa_pyro]

It is also called yellow powder, and it needs to be molten to detonate. From what I have heard it burns very fast, but some sources say it violently detonates. Try putting 1/4 a gram on a spoon(metal of course ) and heating it from a distance with a candle or a burner. One source said the optimal ratio is 55/27/18.

Edit: styro beat me too it.

After doing some more research, the mix is supposed to be very friction sensitive once molten. It used to be used as bullet primers.

[Chemguy]

I just tried the 3:2:1 mix, 1/4 teaspoon thing, and it burnt with rather large flame, afterwards it crackled and some sparks went into the air, but very slow, maybe I heated the spoon up to fast, and didn't give it time to melt. Has anyone else made any of this?
If so what was your results?

[Chemguy]

Thanks mumbles for the name change. Sorry I didn't find the yellow powder thread in the newbie section, I didn't Know that it could ber called that.

[rocket]

I’ve made yellow powder once I used sodium carbonate instead of potassium. I just melted it until it went dark brown then exposed it to a flame, it pops pretty loud too, just watch out for bits of fly yellow powder the a tad on there hot side.
Oh and try not to let the sulfur in the mix light as this will make the mix just burn, if you really want to you can try and blow it out.

[Chemguy]

I've tried blowing out sulfur before, it's not easy . But thankyou for the advice. I must've heated it too fast like I said before.

[Mardec]

You can just melt the K2CO3 and the S together.
Cool it and grind it up and then mix it with the KNO3.
You can also just buy K2S of Na2S..

[Mumbles]

You can just melt the K2CO3 and the S together.
Cool it and grind it up and then mix it with the KNO3.
You can also just buy K2S of Na2S..

Actually you can't. It's quite easy to tell from the colors. Melting accomplishes getting it very well mixed. The colors of the mix indicate polysulfides, of which you can't just buy. From all the research I've read on it, all 3 constituents are required to be melted together for optimal preformance. I am not sure on the kind of products formed, but the colors do indicate polysulfides of some sort. So buying K2S will not be acceptable.

[Mardec]

I am sorry then, I tought it would just form normal sulfides.

But about the melting speratly part I am right no?
I remember that because I read it on another forum.
So it isn't my idea, but people there said it worked..

[Chemguy]

Mumbles, you can buy some polysulfides, lime sulfur is calcium polysulfide in solution. It is deep red. I imagine that it would be possible to evaporate the water off and get a pure version, but it might decompose i'm not sure. I agreethat all the stuff should be melted together, mixing in the KNO3 after melting the S and K2CO3 is kind of pointless, but it might work well for some other things.

Also you can (apparantly) make Potassium polysulfide by heating S with KOH. I imagine this would merely make Potassium sulfide though.

[shadopyro]

You mentioned that someone said somewhere that it can be used as some sort of black powder substitute. 'Fraid it cant, i tried melting it before in a spoon then cooled it. Cracked up the end product and it was actually rather fast burning. The only problem i guess would be if it were to go off when trying to melt it slightly. (Thats why i only tried it in a spoon!)

[Chemguy]

Yeah, that would be bad, too dangerous to get enough to be useful really, might be usefull for a sky rocket (is that what they are called over there? As it would probably give quite a good lift.

[styropyro]

Yeah, that would be bad, too dangerous to get enough to be useful really, might be usefull for a sky rocket (is that what they are called over there? As it would probably give quite a good lift.

If you did make a rocket out of it you would most likely need to make it a nozzleless one like the ones mentioned here . That would be pretty cool to see a yellow powder powered rocket, but because it burns so fast you would probably need a really strong tube even without a nozzle. And if this stuff detonates then you probably couldn't use it as a fuel at all. But I wonder if one could use dry mixed yellow powder without melting it together and using it kind of like a black powder rocket fuel.
I wonder if yellow powder is very friction or shock sensitive as a powder, because it would be cool to see how it would work as a ballmilled powder, but it isn't worth risking your saftey (and precious ballmill ) to try it. It most likely wouldn't work as good as melted together but it would be better then just mixing it.

[pa_pyro]

From what I have read it used to be used as primer for bullets, I think once melted it is very shock sensitive. If used in a rocket it might end up being one heck of a CATO...and I like my ballmill ( and appendages, I wouldn't think about using a mortar and pestle!)

[Chemguy]

Well I had a crack at this again guys with home made Na2CO3. I heated it slowly, and it worked well. A report followed with a flurry of flame. I am very happy.

You can just melt the K2CO3 and the S together.
Cool it and grind it up and then mix it with the KNO3.
You can also just buy K2S of Na2S..

This is not going to work as it is completely against the point like I said before. K2CO3 and S can react on there own too. Also for the best report and/or fastest burn rate, It needs to be melted at the time. Cooling it down afterward will slow it down but it will be useable without being hot. I will try post a vid if I can find my video camera .

[pa_pyro]

My pot.carbonate will arrive in a few days and I will be able to do some testing. I have an old toaster oven and some extension cords so I can experiment in my back yard. To start I'll stick with smaller amounts to see just how powerful this stuff is. I have seen different info on the deflag/detonation rate of the powder once melted. From what I have read the optimal ratio is 55/27/18 KNO3/K2CO3/S. I have seen different reports on the VOD between 1400-3400mps. If this is true it may have use as a new primary.(although it is very dangerous to make/friction sensitive. It would have to be carefully made on site) People on rec.pyro say that there are 3 hydration states that affect the power of the mix. They are dark black=fastest, reddish=slightly slower, and yellow=slowest. Time to get back to researching... and chemguy, what is your method of producing Na2CO3. Maybe Na bicarb. decomp?

[Mumbles]

Boiling a solution of NaHCO3 will yield you Na2CO3.

[Chemguy]

Yes it is Na carb decomp. It is easy I think. What I did was get about 20g of NaHCO3 add about 10mls of water so it's a sludge and boil it. Then leave it to dry. Then I baked it over a flame a bit mored to get rid of anymore water.

And I managed to film it. It is shitty quality because I used my photo camera film which sucks for quality, and makes huge files, so I recorded it on quick screen recorder, making that file size 20 times smaller. The sound in real life was about 6 times louder. In other words a lot. Here is the file. It is about 2 grams.

Yes, the state of my lab is embarrassing

EDIT: It seems that the download is hard to work. So right click it and save as. Save it as fulminate.avi. It works fine like that.

Attached Files

•  Fulminate_2.avi   704KB   156 downloads

[Chemguy]

Update.

I found out the less you use (to an extent of course) the cleaner and (usually) louder the report is. I did one gram a while ago, it was much better than the one that I posted ^^up there^^. Also I tried about 10grams. It was obviously a bit bigger, but there was a flame that lasted about 3 secs afterwards. Also I tried lighting some on its own, no melting, no heating, no milling etc. It hardly lit, it was like KNO3 sugar except 10 times slower, only half of it burnt. I knew that it would be slower because at lower temperature it doesn't react as fast and it isn't mixed as well.

Also I have found out a system of knowing when it will blow. First it starts smoking, probably some sulfur melting and evaporating. Then it stops smoking as it all mixes, and then it blows!

Anyone else made it???
come on, why not, it takes only 1 gram to make a report, and the suspense before it blows is real bad...