I understand and acknowledge that I may be banned for posting a new topic on my first post; I fully accept that if it is deemed necessary. On to the main part of this post, I have been experimenting with using different nitrates for blackpowder/lift powder, and I would like to share this information with the forum.

All stoichiometric calculations done by myself.

Standard blackpowder:
74.8% KNO3 13.4% C 11.8% S ----> N2 + 3 CO2 + K2S
Not friction or shock sensitive, burns with an orange flame; the normal properties of blackpowder, used as the control group.

Barium nitrate blackpowder:
79.3% Ba(NO3)2 10.9% C 9.8% S ----> N2 + 3 CO2 + BaS
Slightly shock sensitive, not friction sensitive as near as I can tell, burns with a light green/orange flame. More smoke than control.

Strontium nitrate blackpowder:
75.6% Sr(NO3)2 12.9% C 11.5% S ----> N2 + 3 CO2 + SrS
Not shock sensitive nor friction sensitive as near as I can tell, burns with a red/orange flame. Approximately the same amount of smoke as control.

While the control group is the easiest on the budget, the usage of other nitrates for blackpowder seems to be an option if necessary or desired. Barium nitrate and strontium nitrate compositions have moderately toxic smoke; when experimenting with compositions using either, take precautions not to inhale any substantial quantity of smoke.

While you equations are all very neat and pretty, I should like to point out that the products of combustion of BP are way more complex than that. A quick run through PROPEP, with your formula for KNO3 BP gives the following products with their relative proportions :

0.74183 CO2 0.37316 CO 0.36990 N2 0.23040 K2S*
0.12762 K 0.07237 K2SO4* 0.02899 SO2 0.00882 S3
3.27E-03 K2SO4 2.16E-03 S2 1.33E-03 SO 6.49E-04 CSO
7.34E-05 S2O 5.49E-05 K2 2.56E-05 S 7.99E-06 S4
4.71E-06 KO 2.09E-06 K+ 1.93E-06 CO2- 1.35E-06 NO
7.14E-07 KCN 1.41E-07 S- 1.35E-07 NS 1.34E-07 CS2

Have you never noticed how BP smoke reeks of SO2?
Although this is only based on a simulation, and this is what you get at 1734K , I think I've made my point clear :rolleyes:

Very good that you are contributing. But I have no other nitrates to play with apart from KNO3 and I think most other people are the same apart from Ca, NH3 and Na nitrates which are pretty much usless in comps. So all in all good job can you get pictures? I'd be interested just out of curiosity - you can never have enough knowledge!

Third_Rail, we have no problem with new members making new threads on their first post if they are making a contribution.

What gets people annoyed is newbies making new threads demanding that we help them, usually to a stupid end.

So good try to you and welcome aboard :)

There's indeed something wrong with that equation. SO2 should be formed instead of sulfides.

It's not easy to match compositions with more than 3 oxidizers/reducers, because several percentages have a valid outcome.

Anyway, good first post.

Well, actually, I believe that sulfides only form if the BP is improperly mixed or has (even slightly) imperfect molar ratios. The sulfur would then be reacted with oxygen in the atmosphere rather than with potassium from the potassium nitrate, etc. Seeing as this is only my experience with BP, your thoughts may differ and I'd love to hear anything further you have to say.


Oh, and thanks for not banning me. :D

No need to thank. you contributed and opened a topic which hasn't been discussed which basically are reasons not to be banned.

as for your previous reply i would have thought that sulfides would form if the BP was mixed and SO2 would form when the BP was mixed less intimately. i say this because if you have a fat grain of S (less intimately mixed) then as it burns it will be progressively further away from any KNO3. thus further from the K+. if you have smaller grains (more intimately mixed) then they are not as far away so more likely to react with the K+. but ultimately i believe its going to form both to some extent just with a varied ratio between the two. not wholey forming one or the other.

There's a patch of dead grass in my garden that I test mixtures on sometimes, and it smells of H2S when it gets wet, which would indicate that some sulphides certainly form even in good BP.