Zinc + Sulphur + Heat ------> anygood?

[ultma]

What’s the highest amount you would try to ignite?

I have some good quantities of these to elements and I was thinking of some weekend fire works

10g Zn with 5g S I found somewhere as a classroom demo, how much higher could I go with out being too dangerous.

I was thinking of heating a coat hanger or a long metal rod to ignite the mix, with a crash helmet and gloves for protection plus at least three meters for flammable objects like trees, and the kids watching from inside.

Your expert advice welcome

[megalomania]

Sounds like you want to be up close and in person when lighting this stuff off. I can't advise you for this specific composition, but you have the right concerns about safety. Ultimately you have the tools to answer your own question, experimentation with the actual product. Start with small quantities and gauge for yourself how much of an increase in effect you get with increasing masses of reactants.

Naturally the more you mix together at once the more powerful of a reaction you will get. At some point you risk setting yourself on fire at that range. I will go out on a limb here and say just zinc and sulfur will not make a very powerful explosive, sounds more like a pyrotechnic composition throwing off lots of heat, light, and smoke. Even with pounds of the stuff it would just burn longer and hotter instead of all at once, so you current precautions may serve well enough.

[Bert]

This mixture will react at flash powder like speeds if the particle size is very fine and well mixed enough. It will also be friction, static and shock sensitive to some degree depending on how it is prepared, particle size, phase of the moon...

I am aware of a rocket builder who BBQ'd himself badly just carrying a plastic bag of leftover fuel composed of this mix out to burn, and brushing it against a wall. Many exciting debridement and skin grafting sessions ensued.

Start SMALL. Work up only as you characterize the properties of your version of this mix.

[startspark9]

I have experimented with this mixture once or twice and the amounts you are working with are fine but anything more I would not ignite with a close hanger. It just seems some what foolish but a cheap and available sources for fun.

[cracker]

If you are looking for other novelty's for your childeren and want to include the experiment you have talked about I would suggest this.

Use an equal mole to mole ratio. This reaction will create Zinc Sulfide. This is the chemical that is used in indiglo watches and many other glowing products.

You will be left with a white powdery substance after the burn. Keep it as clean as possible and collect this powder. Subjecting it to UV (blacklight) will or "should" produce an intense green glow similar to light sticks that you may have seen for halloween. Zinc Sulfide is realitively safe and is used in some cosmetic "make-ups"

I do not believe that the resulting product remainding after the burn will need any further activation inorder to properly glow. However my knowlege is limited on this topic.

From the sounds of it you are being very carefull and in my opinion a 1-1 mole ratio quantity burn should be no big deal.

: Bert has made an excellent point (further down in this thread) about checking your burn rate first. I would have to agree and say that the burn rates between different products are never the same, perhaps you could just use a fuse or try a small amount first.

[kurtz]

it can be difficult to ignite, depending. you may need to hold a blowtorch on it for a few seconds. but when it goes...this will produce a lot of smoke. that ZnS doesn't just sit there...it goes everywhere.

http://www.angelo.edu/faculty/kboudrea/demos/zinc_sulfur/zinc_sulfur.htm

http://www.ddeville.com/derek/zinc.htm

[c.Tech]

If your crash helmet doesn’t have a visor it would be a good idea to wear safety glasses, your eyes are very precious.

[Bert]

The speed of the reaction will be very dependant on the particle size, and the Zinc will be the more difficult of the chemicals to obtain as a very fine powder. I have seen a DRAMATIC difference in burn rates and ease of ignition in this mixture using different sources of Zinc powder, as well as large differences in prime required and burn rate of the Zinc fueled granite stars I have made. Don't hand light a full mole equivalent batch until you've seen how YOUR Zinc behaves...

[FUTI]

I think that there was some amateur rockets using Zn+S mixture combination so I think that flying everywhere thing is correct. I never ignite such thing myself only Fe+S in highschool in testtube when they actually give kids to do some real chemistry experiments so I don't know for sure how this mixture will act, but if I were you I would expect it act at least as powerfull as blackpowder propellant (to be on the safe side) and design my experiment having that in mind. Powdered zinc is a rare bird and a good mesh grade is needed to get a good burning rate.

[ultma]

All in all it turned out good the metal rod wasn’t enough to light all the time so I used a primus burner for most of it. I tried combos of 10 15 and 20g of Zn and 5, 7.5, and 10g of S

Next time I will record it :D


The Zinc is a nice powder in a blue tin from the old company BDH now consumed by Merck; I use it for a fungicide test at work. The Zn from work does have a few aggregates of powder that need crushed, possibly due to slight moisture contamination.

I don’t have sulphur at work and used flowers of sulphur; however my friend is a truck driver so he can get me some from a bulk store that’s used for the same thing I guess.

Now if I were to dry the Zinc and Sulphur would I get an even better flash. I have access to a 100C drying oven that’s temp checked daily and verified once every six months.

I also have zinc activated with copper but its not powder but quite large flakes.

[shooter3]

My pal did 4 lbs in a rocket when i was a kid. The shockwave passing through my brain altered the neurons, causing extreme pyromania. I'll never forgive him!

This is powerful stuff. If you make rockets with it, you can make a grain with lots of pressure from a hydrolic jack (done REMOTELY!!).

[Cobalt.45]

This is currently in eBay:
300 mesh Zn powder, $3.00/lb plus $6.00 S&H for as much as you want to buy.

I can say from experience that it's as good as advertised. It was in my hands in three days from the time I placed my order.

Oh, and for the record I am in no way affiliated with this site or person. I just thought it might be of some interest to those reading this thread.

PM for the url.

[Universal]

This stuff burns very differently depending on how much you have, a small enough pile doesn't burn so much as just react giving off heat but little flame, larger amounts - 10grams will burn fsat, fumph! It also sends little bits of ZnS every where. Be carefull, and keep awat from chlorate/perchlorate, as you know!

[megalomania]

I am moving this to the pyrotechnics section...

[FullMetalJacket]

From what I've always been told, Zn/S, at least in the category of rocket fuel, is a real bitch to get to light properly and produces dense, nasty SOx smoke.

I may be wrong, though.

[Cobalt.45]

"Micrograin" is a subject unto itself, for sure.

It is as good of a rocket fuel as the person who researches and formulates it. It's not as forgiving as some fuels, like KNSU or black powder, but some people swear by it.

Probably after much swearing at it.

[Horrigan]

I just tried this powder today, about 10g (2/3 Zn 1/3 S), with very fine Zn powder that I took from the school (couldn't resist), and, weel, it was really faster than any flash powder I have tried ! and not so hard to ignite (as hard as flashpowder I guess)
Nice powder, seems stable and sensitive enough, but I had the chance to use very fine powder to do so...

[KMnO4]

I once made this mixture with very coarse zinc powder and it took 9 seconds to light with a propane/butane torch.

[ultma]

10g of Zinc powder 5g of Flowers of Sulphur ignited with KMnO4/Glycerol

This same powder has burnt much much faster than this when lit with a blowtorch.

http://www.zippyvideos.com/3910802346524176/1._zn__s__zns_1384k_stream/

[Lewis]

Strangely enough, the above video reminds me a lot of another composition I've been playing with: "flash" with Al from the infamous PK Unlimited. I had used Agro grade KNO3 with sulfur and the Al.

The burn rate was the same, the amount of smoke was the same, and the yellowish green colour was identical. What gives? Is PK putting zinc in their aluminum?

[Horrigan]

I made a quick movie of this powder, which is really powerful:
http://www.megaupload.com/fr/?d=ODDWEJYY

[nbk2000]

I must say, that's a remarkably clever idea there - holding a lighter in your bare hand as you light a pyrotechnic powder with the flame. :rolleye:

[Horrigan]

Well, I agree, this was not a good idea, but I did not want to use a simple powder for that and I doubt a simple blackpowder fuse would have been able to ignite that, moreover, this was a very littre amount of powder, less than 1 gram, I didn't get hurt by that.

[nbk2000]

Must be nice to always be able to predict what will and won't hurt you, in advance. :p

Don't get started with bad habits like this and you'll still have ten fingers in ten years.

[Horrigan]

Yeah, you're right, I'm a bit stupid :p I'll take more precautions now. In fact, I take a lot of precautions with everything which I have in great quantities, but when it's 2g of a powder, I don't see any danger ^^

[Bert]

Beginner's luck and a long piece of visco have saved many a fool. I have only one scar on my hands from pyro experimentation. The sample that caused 6 stitches worth of evulsed tissue and a broken finger bone weighed less than .25g.

[Horrigan]

I was just talking about unconfined small quantities of oxider/fuel powders, not AP, HMTD or else :p
I don't use AP but if I had to do it, I wouldn't use more than a few grams for a detonator, and I'd wear leather gloves and glasses !