823 replies to this topic

[Mumbles]

As far as green flash goes, you can make a decent green flash with:

50 - Magnesium
50 - Ba(NO3)2

Replacing Barium nitrate 1:1 for the barium chlorate formulas above should in theory work.

5 - Ba(NO3)2
4 - Mg
1 - PVC should work even better.

I've used both of the above formulas with nitrates. I was too close to really see a difference, but from what I recall from the reflections, the one with PVC was better, probably for good reason. The first has a noticeably green hue though.

[pyrotechnist]

Failing flash or negative flash has anyone tried using golden powder as a burst? That is the potassium nitrate, potassium carbonate and sulphur formula. Looks like seriously energetic stuff.

[seymour]

Failing flash or negative flash has anyone tried using golden powder as a burst? That is the potassium nitrate, potassium carbonate and sulphur formula. Looks like seriously energetic stuff.

I know that this forum has relaxed slightly, but in years gone by the mention of that mixture has resulted in locked threads and warnings.

It could be the very dangerous ways many people make it, or the severe hygroscopicity, or the power and sensitivity of it, but the reasons that it was and perhaps still is something that we should not talk about here, will be the same reasons that it is not a suitable material for us to use in foreworks.

It is a shame, because if it were safer and better to handle it would be attractive, as it is made of such cheap chemicals.

[CCH Concepts]

What I mean is that it will go CaSO4 + Mg ---> CaS + 4 MgO

Forming Ca + S + 4 MgO wouldn't be as energetically favorable as forming CaS. It would take a bunch of extra energy to break it apart into Ca + S. Calcium Sulfide is more stable than Magnesium Sulfide, so even with excess Magnesium, you couldn't form MgS and Ca metal.

so in theory they could have as much power as KClO4/Mg on the basis of 4 oxidized Mg atoms. what about this the negative explosive in the

MgSO₄ + 4 Mg → MgS + 4 MgO + 353 kcal

this would infact be quite energetic can anyone quantify the energy value as to how much energy this actually is and what would be very interested is if any now the chemistry involved in calculating the energy output of a given balanced formula.

[Mumbles]

In any case golden powder is made from KNO3 and ascorbic acid. The KNO3/K2CO3/S mixture is yellow powder.

[portfire]

Ok, did a search and the only thread that had most hits was this one........So, in a day or 2 I will be milling passivated Mg, it's clummed and I have the media to break it down (thanks you know who) back to 400# within a few mins.

I know the dangers but would like some input..It's passivated with linsed oil....

[MDH]

so in theory they could have as much power as KClO4/Mg on the basis of 4 oxidized Mg atoms. what about this the negative explosive in the

MgSO₄ + 4 Mg → MgS + 4 MgO + 353 kcal

this would infact be quite energetic can anyone quantify the energy value as to how much energy this actually is and what would be very interested is if any now the chemistry involved in calculating the energy output of a given balanced formula.

Not quite. Potassium perchlorate requires a number of times less energy to decompose which is part of why it is so widely used, though it contains less oxygen. A sensitizer such as sulfur would probably be beneficial for the reaction in the case of sulfates by spreading superheated gas throughout it very quickly and quickening their decomposition.

Of course, any oxyanion can probably deliver a powerful performance with magnesium given it is such a strong reducer. I was told in the copper borate thread that it is being used as a flash oxidizer with magnalium.

[CCH Concepts]

Not quite. Potassium perchlorate requires a number of times less energy to decompose which is part of why it is so widely used, though it contains less oxygen. A sensitizer such as sulfur would probably be beneficial for the reaction in the case of sulfates by spreading superheated gas throughout it very quickly and quickening their decomposition.

Of course, any oxyanion can probably deliver a powerful performance with magnesium given it is such a strong reducer. I was told in the copper borate thread that it is being used as a flash oxidizer with magnalium.

how about calculating the energy release, any idea of the science behind this?

[Mumbles]

He's talking activation energy, not total energy release.

[MDH]

The lower energy it takes to decompose KCLO4 makes it a better flash, which is why I theorized that sulfur would ease the negative explosive reaction.

[digger]

how about calculating the energy release, any idea of the science behind this?

Yep easy enough to do. You just need the stoichiometric reaction and the heats of formation of the reactants and products. the difference between the heats is the energy released or consumed.

[CCH Concepts]

Yep easy enough to do. You just need the stoichiometric reaction and the heats of formation of the reactants and products. the difference between the heats is the energy released or consumed.

where would i find the values for the heat produced. is the a known table of values or something?

[Mumbles]

There is a book called the CRC reference manual. CRC stands for chemical rubber company, which is who originally put it out. You can find older copies for next to nothing because all the libraries and science labs need updated ones. If that book doesn't have it, I don't know where. Otherwise you can find values on the internet, even Wikipedia should have the values for common things.

[digger]

Try this Click

[CCH Concepts]

i had a go at KClO4/Al flash, but i think i went wrong somewhere

3(KCl04) + 8Al = 4(2Al3O) + 3(KCL)

KCl04 = 742 Cal/g so 2226 cal/g
KCl = 1397 Cal/g so 4191 cal/g
Al2O3 =4000 Cal/g so 16000 cal/g

(4191 + 16000) - 2226 = 17965 or approx 18Kcal/g

that doesnt seem high enough?

Edited by CCH Concepts, 25 April 2010 - 12:46 AM.