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testimento
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Black powder without KNO3 and S?
Ok so I am in need of black powder for use as a propellant material that has compatible pressure increase for projectile ejection purposes. The major
problem with me lies with the composition for the powder.
I have no potassium salts available, unless in very expensive or complicated ways, but sodium, calcium and ammonium salts are, though. Also I have no
access to elemental sulfur whatsoever.
I searched through some sources and they cited that a very slightly less powerful black powder can be made from 80:20 KNO3:C composition. The sodium
and calcium salts downfall is with the moisture, but this shouldn't be a major problem for my purpose because the propellant material is to be sealed
in plastic/metal container. Sodium black powder is referred to have very high initial pressure peak, so it is used in quarrying rather than
propellant. Calcium black powder I have no sources, and ammonium salts, by my knowledge, tend to be the far end of the rapid pressurization of
composition pyrotechnics and therefore usually not recommended.
So, is it possible to make a compatible substitute from a sodium or calcium nitrate based compositions for black powder propellant?
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Metacelsus
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I made black powder using NaNO3 instead of KNO3 (same molar quantity). It performs similarly to usual black powder. However, it is quite hygroscopic
and produces an intense yellow flame.
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DubaiAmateurRocketry
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For burn rate, potassium nitrate works one of the best in black powder compositions out of other nitrates. However if you really cant purchase
potassium nitrate, even in fertilizer form, then you could try perchlorates, such as potassium or ammonium perchlorate. those salts have a good
pressure-burn rate curve that burns fast enough for good projectile''ejection'' speed
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testimento
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Calcium nitrate is of my particular interest. The formula next to KNO3 (101g vs 164g) dictates that I should be able to use about 61 grams of it for
every 100 grams of KNO3 to get same outcome, and much more importantly, it is easily available. From this I counted that I could use 5 moles of
calcium nitrate with 16.6 moles of carbon powder (approx. 800g of Ca + 200g of C) to get ideal performance.
How is table sugar as a regulator instead of sulfur? It is used in fuse mixtures and I thought it could perhaps work aside?
How would sodium perchlorate, carbon powder and 0-x% of sugar work?
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hyfalcon
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Mr. Sleeter has forgotten more about this subject than we will have to time to learn.
http://lib.freescienceengineering.org/view.php?id=215727
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hyfalcon
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The picture is right but that download is NOT the book I have. Missing about 150 pages and I don't even recognize the 19 pages in this download.
Still good info though.
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Bert
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If you can't find Sulfur in any country on earth, you are not trying.
Assuming you have anhydrous nitrates, the physical form of your nitrate/carbon based propellants likely matter more for the shape of the pressure
curve than the particular nitrate you choose. Ammonium nitrate will have the highest specific impulse, as the reaction products are virtually all gas.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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DubaiAmateurRocketry
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Ammonium nitrate does not burn well at all without metal powders and have really one of the slowest burn rates, if you want to use black powder which
is meant to burn really fast. perchlorate usually have higher burn rate than nitrates, and potassium's salts have high burn rates. calcium nitrate is
very hygroscopic and usually comes in hydrated form, unusable. You can purchase oxidizers such as KNO3 very easily from local fertillizer shops, I
bought 10 Kg of cheap KNO3 few years ago in fertillizer mart and it have 98% purity, enough for pyrotechnics, and I still have half of it left.
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Bert
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For that matter, conversion of calcium nitrate to potassium nitrate is trivial-
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Trotsky
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Convert the calcium nitrate to potassium nitrate.
You can give CaNO3 a shot of You can get it nearly anhydrous. Good luck there. Ammonium nitrate is a terrible choice. It burns like shit. I've
tried VERY hard to get it to work, because as he it's said above, it should have a very high isp, but it just doesn't work.
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Zyklon-A
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Yes, but he said that he does not have any potassium salts at all.
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Zyklon-A
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If you have CaNO3 you can make flash powders that burn much faster than BP.
CaNO3+Al is hard to ignite, try CaNO3+MG, not sure about the ratios, sorry, try twice as much CaNO3 as Mg.
I would try myself, but I don't have any CaNO3 right now
[Edited on 11-12-2013 by Zyklonb]
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Bert
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The only reason one would not have access to Potassium salts useable to convert Calcium nitrate to Potassium nitrate would be that one was in prison
or in orbit.
Potassium chloride and/or Potassium carbonate are available anywhere in the world.
Sodium free salt substitute. Water softener salt. For gods sake, anyone with some water and wood ash has access to all the potassium carbonate
available that they would care to extract.
Similar to the claim that he can't get Sulfur, the only thing standing in the way would be ignorance or lazyness.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Zyklon-A
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Keep in mind it was him who said that he did not have any K-salts, not me, I should have thought of wood ashes though.
True about sulfur for sure, I can get sulfur at a gardening shop, $10 for 5lbs, and I've heard that that's expensive even.
[Edited on 11-12-2013 by Zyklonb]
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Zyklon-A
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Quote: Originally posted by Bert  |
The only reason one would not have access to Potassium salts useable to convert Calcium nitrate to Potassium nitrate would be that one was in prison
or in orbit.
Potassium chloride and/or Potassium carbonate are available anywhere in the world.
Sodium free salt substitute. Water softener salt. For gods sake, anyone with some water and wood ash has access to all the potassium carbonate
available that they would care to extract.
Similar to the claim that he can't get Sulfur, the only thing standing in the way would be ignorance or lazyness. |
I'll bet that one could even get potassium salts in prison, not sure about space though.
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Vikascoder
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If you can't access potassium salts and sulfur then u could use sodium nitrate and sugar and charcoal it also gives a good thrust
Girls break promises like a small child breaks pencil tips so don't trust girl bcoz no girl=no tension
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Zyklon-A
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It still would not burn as fast as BP.
I just got some CaNO3, so I will try CaNO3+Mg.
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Vikascoder
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If you have sodium nitrate and magnesium and u r interested in making flash powder then use sodium nitrate instead of calcium nitrate because sodium
nitrate will give u much better results
Girls break promises like a small child breaks pencil tips so don't trust girl bcoz no girl=no tension
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Zyklon-A
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Would NaNO3 work better than KNO3,
Because I have a lot of KNO3.
I just got CaNO3 to try and see if it works, not because I didn't have KNO3, or NaNO3.
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DubaiAmateurRocketry
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| Quote: Originally posted by Zyklonb | Would NaNO3 work better than KNO3,
Because I have a lot of KNO3.
I just got CaNO3 to try and see if it works, not because I didn't have KNO3, or NaNO3. |
Depends what are you using it for.
In general, KNO3 is the most prefered, it actually ''burns'' with some fuels, for other nitrates, you would need much more heating and sometime
extinguishing without continuous heating. Such as Sodium/ammonium nitrate.
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Zyklon-A
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Good, I have like 3 lbs of KNO3, just made a ball mill for Al powder.
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DubaiAmateurRocketry
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Al powder ? are you doing it with KNO3 ? Aluminum powder have a very high temperature of activation to burn or make flash powder, due to its oxide
layer protection and its high boiling point.
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Zyklon-A
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I know,when I'm using Al powder, I add a pinch of sulfur, it lowers the activation temperature considerably, I can light it with a glowing splint.
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DubaiAmateurRocketry
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| Quote: Originally posted by Zyklonb | | I know,when I'm using Al powder, I add a pinch of sulfur, it lowers the activation temperature considerably, I can light it with a glowing splint.
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I think I tried that before however it burned much worse than using magnesium or titanium.
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Pulverulescent
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| Quote: | | Ammonium nitrate is a terrible choice. It burns like shit. I've tried VERY hard to get it to work, because as he it's said above, it should have a
very high isp, but it just doesn't work. |
It will work with a sufficiently strong ignitor . . .
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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