Sciencemadness Discussion Board - General question about experience with picric acid

General question about experience with picric acid

Tkuze - 14-5-2019 at 02:12

Obviously picric acid was a staple of militaries such as the japanese during the beginning of the 20th century.. and germany bought tons of aspirin and salicylic acid pre-war from the US to manufacture it. My experience has been that although PA has a high value as an intermediate to picramates and DDNP, but it seems useless as a secondary. Even testing using an improvised #8 cap seems to not do much. Theres always a sort of mist of yellow and mild DDT, whereas replacing the PA with a nitrated polyol works magnificently. Priming mixture:lead styphnate 200mg, primary: lead azide (dextrinated; 90mg or pure; 70mg), Secondary:700mg pressed + 300mg lightly pressed ETN, PETN, MHN, RDX MIX(50/50 with ETN to improve sensitivity). This works excellent, but looking back at the first compound made which inspired curiosity in this field, picric acid, I wanted to use my experience to test its effectiveness again
Its seems to not be bery good at all, besided staining everything. Even in combo with melt casts, it seems to have a negative effect. What do you guys think? Assume I havent been doing anything right

Herr Haber - 14-5-2019 at 04:12

Nitrated polyols dont require the same level of confinement to impress you as PA does. Also, they tend to have a higher RE than picric acid.
I can only assume you got that "yellow mist" because some didnt go DDT.
Only suggestions I have is to use a stronger confinement and find every topic about the subject where Rosco contributed. His words are gold (when it comes to picric acid).

Tkuze - 14-5-2019 at 05:05

Thanks man. I was curious because its used so commonly when you watch WW1 and WW2 documentaries and seems inneficient. hey usually combine it with TNT

hissingnoise - 14-5-2019 at 08:43

Quote: Originally posted by Tkuze

They usually combine it with TNT

Though PA is more sensitive than TNT ─ it has better OB, brisance and power than that compound.

Its acidic nature and relatively high sensitivity were the factors that militated against its wider acceptance after WW1...

It was said that because British PA-filled shells exploded on impact with armour, whereas German shells with TNT could penetrate armour before detonating, the British lost more ships and men than did the Germans in the battle of Jutland.

Tkuze - 14-5-2019 at 12:40

Thats a very good point. The coolest thing in WW2 is the use of HMX in the fat boy as the uranium slug propellant. Are there any methods to produce HMX without Acetic Anhydride?

underground - 14-5-2019 at 13:08

Quote: Originally posted by Tkuze

Thats a very good point. The coolest thing in WW2 is the use of HMX in the fat boy as the uranium slug propellant. Are there any methods to produce HMX without Acetic Anhydride?

Synthesis of DPT ftom hexamine then nitrate the DPT with FNA.

caterpillar - 16-5-2019 at 10:40

Kalium picrate explodes been ignited in confinement. No need in the detonator. I initiated mixed AN+ammonium picrate, a mix that is obviously less sensitive than pure picric acid, with the aid of 0.5 gr TATP.

NeonPulse - 16-5-2019 at 19:25

It sounds like you have not fully nitrated the Precursor. In my opinion Picric Acid is very powerful and a worthy secondary. I had this problem with the yellow cloud and little damage to test plates and reworked my procedure to produce a very pure product with all the desired properties. It’s probably the most versatile explosive you can synthesise as it is a precursor itself to many other interesting explosives. I’d say almost perfect- except for the yellow staining it leaves everywhere.

caterpillar - 16-5-2019 at 19:44

Quote: Originally posted by NeonPulse

It sounds like you have not fully nitrated the Precursor. In my opinion Picric Acid is very powerful and a worthy secondary. I had this problem with the yellow cloud and little damage to test plates and reworked my procedure to produce a very pure product with all the desired properties. It’s probably the most versatile explosive you can synthesise as it is a precursor itself to many other interesting explosives. I’d say almost perfect- except for the yellow staining it leaves everywhere.

Probably, you are right. I read about a simple test- 0.5 gr in tinfoil on a steel plate. Strong impact with hammer must cause an explosion if not-you have a mix of dinitrophenols.

NeonPulse - 17-5-2019 at 15:47

But even the Hammer test here isn’t reliable. I’ve made some incredibly pure picric acid before with huge well defined crystals almost clear and although it detonated powerfully confined and provoked with some Lead Azo -Clathrate, it took several very solid whacks to set it off. Often just pulverising it.
The times it did go off though, it was loud and plenty of orange sparks with the telltale smell.
It’s obvious but In my opinion The only way you can truly tell the purity is to run a known synthesis, carefully, with known parameters leading to predictable product.
By far The best method I’ve found uses NaNO3 and was developed
by Rosco Bodine.
I did a video of
https://m.youtube.com/watch?v=7es7kMAZyFY&autoplay=1

Tkuze - 17-5-2019 at 16:04

I am really convinced that the product is fully nitrated. I have used multiple procedures and settled on the best of all combined. Do you have any specific advice to improve synthesis, like using pure acids? I am positive it is pure because it was used for DDNP and the product was pure.

Tkuze - 17-5-2019 at 21:21

Also, I have watched that video many times, but I never used nitrate salts. I used highly pure nitric acid

caterpillar - 18-5-2019 at 01:10

Nitrates, dissolved in the conc H2SO4 are more powerful nitrating agents, than the usual mix of HNO3+H2SO4. I described once the method that U used. 250 gr of phenol + 800 gr of H2SO4 94%. I used a hot water bath but found that is is not necessary. 1000 gr of KNO3 + 1600-2000 gr of H2SO4. Both solutions must stay for a night. Next day slowly add phenol, dissolved in H2SO4 to nitrating mix. The process takes hours- do not let the temp leap up, try to keep the room temp or slightly above it. Then mix must stay for one night more. Next day slowly increase temp up to 100 Celsius by means of boiling water bath. Keep mix at 100 Celsius for one hour. Then pour it into large enough volume of cold water with crushed ice. Filter yellow crystals and wash them with a small amount of cold water. Oh, and if you wanna make some salt, do not dissolve it into the water. Add a small amount of water and mix slurry with K2CO3, NH4HCO3 and so on.

Tkuze - 18-5-2019 at 12:03

Thanks. I will give it a try using salicylic acid. I want to just compare to synthesis of stypnic acid. During both synthesis, adding H2SO4 and starting material and heating for 30-60 min results in both solutions becoming a lilac colored mixture, which is cooled and then nitric acid is slowly added with heavy stirring and then heated up slowly to 90-100C and heated for 1h, where a large amount of bubbling occurs and then bright yellow precipitate forms. This is heated for an extra hour or two and excess nitric acid or salt is added to ensure nitration. In the case of styphnic acid, an eggshell white compound is isolated. This is added to an equimolar solution of NaOH until fully dissolve and solution is red. Lead (II) nitrate is dissolved in H20 and kept at 65C. The stypnate solution is added dropwise while warm over several hours, resulting im a yellow or orange precipitate. Nitric acid is slowly added at the end of reaction to turn the yellow precipitate dark orange/red. This is filtered and washed. Once dry, it is a very powerful and sensitive priming mix. This is definately trinitrated. Basically same procedure as picric acid. And the styphnate is definately the corret lead salt. But ill try your procedure. And buy phenol

caterpillar - 18-5-2019 at 18:44

I made styphnic acid, but the first attempt was not successful. I tried to make is just as I made TNP, but when I had placed resorcinol into H2SO4 it turned into some stone. I made it via nitroso derivative- the first stage is the reaction of resorcinol with nitrite and diluted H2SO4, the output is brown powder. The next stage is the reaction with diluted HNO3- sorry, I do not remember all details. But I made it.

caterpillar - 18-5-2019 at 22:49

Taken from Jared Ledgard: Step 1: Preparation of Dinitroresorcinol monohydrate
Procedure:
To 16 liters of water add and dissolve 440 grams of resorcinol, and then 452 grams of 98% sulfuric acid. Immediately
thereafter, add 6800 grams of crushed ice to mixture, and then stir the mixture vigorously until the internal temperature of the
mixture reaches about 0 Celsius. Then prepare a solution by dissolving 600 grams of sodium nitrite into 3200 milliliters of
water, and then add this sodium nitrite solution to the sulfuric/resorcinol mixture over a period of 6 minutes while vigorously
stirring the mixture and maintaining its temperature below 5 Celsius. After the addition of the sodium nitrite solution, continue
to stir and cool the reaction mixture below 5 Celsius for 30 minutes. Note: A precipitate will begin to form. After the 30 minute
period, filter-off the precipitated dinitroresorcinol monohydrate, and wash with several hundred milliliters of cold water (use
gravity filtration).
Step 2: Preparation of Styphnic acid
Place 3000 milliliters of 40% nitric acid into a beaker, and then gently heat this mixture to about 30 Celsius. Thereafter,
carefully mix the moist filter cake, prepared at the end of step 1 to the nitric acid solution over a period of about 30 minutes,
while stirring the nitric acid and keeping its temperature around 30 Celsius. Immediately after the first addition of the filter
cake, nitrogen oxide gases will be evolved, followed by the formation of a foam (the foam will dissipate after about 10
minutes). After the addition, raise the temperature of the mixture to 95 Celsius, and then hold this temperature for 1 hour. After
heating for 1 hour, remove the heat source and allow the reaction mixture to cool to room temperature. Note: A precipitate will
form. When the reaction mixture reaches room temperature, filter-off the precipitated product, wash with 300 milliliters of 2%
nitric acid, and then with 600 milliliters of cold water. Then vacuum dry or air-dry the product. The result will be pale yellow
crystals, well suitable for use in preparing lead styphnate, or styphnic acid compositions.
At this stage you may use H2SO4 + some nitrate instead of HNO3

hissingnoise - 19-5-2019 at 03:52

Oh no, not Jared Ledgard! Aaarrrggghhh!!!

Tkuze - 19-5-2019 at 14:32

Thanks for the procedure. Ill try it small scale. Im curious what your opinion is on the product originally described in this thread. The lead styphnate currently is placed on a metallic spatula and a flame is slowly introduced from below, resulting in immediate DDT.

caterpillar - 19-5-2019 at 15:03

Quote: Originally posted by hissingnoise

Oh no, not Jared Ledgard! Aaarrrggghhh!!!

Yeah, mate, I share your opinion about dear Jared. But I originally took this "recipe" from the other book. And I made styphnic acid, using this method- I only used H2SO4 + KNO3 instead of pure HNO3.

caterpillar - 19-5-2019 at 15:10

Quote: Originally posted by Tkuze

Thanks for the procedure. Ill try it small scale. Im curious what your opinion is on the product originally described in this thread. The lead styphnate currently is placed on a metallic spatula and a flame is slowly introduced from below, resulting in immediate DDT.

My opinion on picric acid is that it is excellent secondary- simple preparation, just for beginners. And some of its salts can be used instead of pure TNP. I love it. Nice color, like pure gold.

Tkuze - 19-5-2019 at 15:16

Ok thanks. Ill remove my bias and retry it and report back

caterpillar - 19-5-2019 at 15:57

Quote: Originally posted by Tkuze

Ok thanks. Ill remove my bias and retry it and report back

Go ahead. I think (but it is the only my proposition) that one can use TNP for blasting caps. 1-2 gr of pressed TNP and 0.5-0.8 gr of lead picrate above.

Herr Haber - 20-5-2019 at 02:54

I'll stay biased towards that guy.

Let's not even point out his many mistakes. But how are you going to trust someone feeding you a synthesis as if it were a cooking recipe if he didnt even try it in the first place ?
Who's gonna believe the guy nitrated 250 grams of phenol like described above ?
What now ? 16 liters of water ?

Looking for lab procedures I dont see the interest of (old) semi industrial method.

Burn this guy's books and get Urbanski instead !

caterpillar - 20-5-2019 at 12:16

Quote: Originally posted by Herr Haber

I'll stay biased towards that guy.

Let's not even point out his many mistakes. But how are you going to trust someone feeding you a synthesis as if it were a cooking recipe if he didnt even try it in the first place ?
Who's gonna believe the guy nitrated 250 grams of phenol like described above ?
What now ? 16 liters of water ?

Looking for lab procedures I dont see the interest of (old) semi industrial method.

Burn this guy's books and get Urbanski instead !

??? I love HE and I haven't written books. I described my own experience. I can only add, that KNO3 can be replaced with NaNO3, but do not use NH4NO3! You'll get lots of NOx. If you dislike semi-industrial methods, divide all numbers by 20, 50 or even 100. And I used not a lab vessel, mate- no- I used 3 liters glass jar with wide throat from-under cucumbers. And who told you that you need 16 liters of water just in one piece? Take three liters of cold water (crushed ice is useful, but not necessary) and put into it 300- 400 ml of the reaction mix. Filter the precipitate and repeat this process again and again.

Tkuze - 20-5-2019 at 18:51

Haha, I never use and probably wont use nitrate salts. Just pure Nitric acid

caterpillar - 20-5-2019 at 20:19

Quote: Originally posted by Tkuze

Haha, I never use and probably wont use nitrate salts. Just pure Nitric acid

??? Why? Salts are generally much more available. There are few compounds, that really require pure HNO3- RDX, HMX, nitroform (add something if you wish). But generally the idea is clear- salts are more powerful nitrating agents for the very simple reason- they do not contain water. BTW, RDX can be prepared with the aid of the usual mixed acid. And mixed acid can be easily prepared if you have Ca(NO3)2.

Herr Haber - 21-5-2019 at 03:25

Quote: Originally posted by caterpillar

Are you Jared in disguise ?

I dislike him and his "cool cookbooks".
One page he describes a normal lab synth, the next one looks like pilot plant production...
What's the point of putting that in a book except to prove you dont actually have a lot of hands on experience ?
If you actually DO a synth, why not post YOUR data ?
Jared just copies and pastes.

hissingnoise - 21-5-2019 at 04:28

Quote: Originally posted by caterpillar

BTW, RDX can be prepared with the aid of the usual mixed acid. And mixed acid can be easily prepared if you have Ca(NO3)2.

(Ahem!) Mixed acid cannot be used for RDX as H₂SO₄ decomposes hexamine ─ and why would you use calcium nitrate for HNO₃ when the sodium salt is less hygroscopic and so much more convenient?

caterpillar - 21-5-2019 at 16:08

Quote: Originally posted by Herr Haber

Quote: Originally posted by caterpillar

Are you Jared in disguise ?

The answer is very simple- I made styphnic acid many years ago. I took the method from one Russian book in a library. The paper text with it was lost many years ago. Now I found a description in Jared's book. I used a similar method, but I used H2SO4 + some nitrate instead of HNO3 for the second stage.

caterpillar - 21-5-2019 at 16:44

Quote: Originally posted by hissingnoise

Quote: Originally posted by caterpillar

BTW, RDX can be prepared with the aid of the usual mixed acid. And mixed acid can be easily prepared if you have Ca(NO3)2.

(Ahem!) Mixed acid cannot be used for RDX as H₂SO₄ decomposes hexamine ─ and why would you use calcium nitrate for HNO₃ when the sodium salt is less hygroscopic and so much more convenient?

Yes, mate, this is what you may read in books. But there is a way to use mixed acid, however. Let's go.
ＣＨＩＮＥＳＥＪＯＵＲＮＡＬＯＦＥＮＥＲＧＥＴＩＣＭＡＴＥＲＩＡＬＳ Vol 16 No 1 February, 2008
ＳｙｎｔｈｅｓｉｓｏｆＫｅｔｏＲＤＸａｎｄｉｔｓＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｓＣａｌｃｕｌａｔｉｏｎ.
Don't be cofused by the word KetoRDX- this method gives the mix or KetoRDX and RDX. Not bad for a method, using mixed acid, eh?
Read this discussion: http://www.sciencemadness.org/talk/viewthread.php?tid=28395 you'll find many interesting there and when Ca(NO3)2 is better than NaNo3

kratomiter - 2-6-2019 at 11:35

In my experience, picric acid is a pretty good secondary and the synthesis is easy. I always make it from aspirin and sulfuric+nitrate mix. The last batch wasn't pure (more obscure yellow color), so be sure you get rid of aspirin's fillers, now I don't know how to remove impurities...

caterpillar - 2-6-2019 at 15:14

Quote: Originally posted by kratomiter

In my experience, picric acid is a pretty good secondary and the synthesis is easy. I always make it from aspirin and sulfuric+nitrate mix. The last batch wasn't pure (more obscure yellow color), so be sure you get rid of aspirin's fillers, now I don't know how to remove impurities...

It is better to make it from phenol- but if it is the problem, use aspirin.

XeonTheMGPony - 4-6-2019 at 20:05

Quote: Originally posted by kratomiter

I used a sort of hybrid method, using 70% Nitric acid and since I was running low finished off with KNO3.

Very well behaved reaction, very good yields too.

second pic is 7 grams being converted to the ammonium salt that too went very smooth and easy

Aspirin is fine, wasting time to go all the way back to phenol offers nothing, so less you just happen to have crap loads of phenol laying about!

kratomiter - 5-6-2019 at 11:12

I don't have access to phenol, so I go with aspirin. I usually get very pure picric acid, I just screwed up the last synthesis in some step.

Tkuze - 5-6-2019 at 11:48

Aspirin extracted and deacetylated to salicylic acid, which is then used creates a much more impure product and tougher reaction than if buying pure salicylic acid. The difference is evident in the sulfonation step, as the extracted and recrystallized salicylic acid/ sulfuric acid mix will form a black solution. Pure salicylic acid/ sulfuric acie mix will form a beautiful magenta/ lilac color.

caterpillar - 6-6-2019 at 13:28

I used H2SO4 + KNO3 or NaNO3 instead of mixed acid. Both worked fine, but once I tried HN4NO3 and got lots of NOxes. The mix in my vessel became like foam full of red gas, the vessel was overwhelmed and I had to interrupt the process.

XeonTheMGPony - 6-6-2019 at 18:07

converted my full batch to Ammonium Picrate. I added strong ammonium hydroxide till just slightly basic, then as it was fully dissolved adjusted to a PH of close to 7 as possible, then boiled solution down.

then slowly allowed it to recrystallize over night, then left in fridge for the day.

[Edited on 7-6-2019 by XeonTheMGPony]

caterpillar - 6-6-2019 at 18:50

Look, Xeon, it can be done easier. Make slurry- picric acid plus some water, not much. Add in small portions NH4HCO3 (or (NH4)2CO3 ) and mix it, while it is hissing. A small excess of carbonate is useful- no free acid. Then put the mix on fresh air and wait when it is dry. No large volumes of water. Same way to make kalium picrate.

XeonTheMGPony - 6-6-2019 at 19:35

this served as the first recrystallization too, I tend to double up things to avoid excessive handling. there was a point to the method used.

MineMan - 6-6-2019 at 19:36

I don’t mean to be ignorant. But. Was Picric acid not an explosive of the very early 1900s, are there not better EMs with simpler OTC synthesis for us clandestine to semi professional scientist?

I feel like I am missing something about the excitement of Picric... can some please correct me if I am wrong? Is it merely a curiousity if not used for other EM synthesis?

underground - 7-6-2019 at 04:03

In my personal opinion you are right Mineman. I actually cannot see any reason why nitrating anything else rather than pentaerythritol. Best yields, best performance and very good stability. Now if something else is going to be found that it can be easily made with OTC chemicals and it have good performance, i will move into it. Most of us looking for something like that.

[Edited on 7-6-2019 by underground]

Tkuze - 7-6-2019 at 05:07

Mineman and Underground- I totally agree. There is only a historical appreciation for PA in my opinion and its a good starting point for EM. I sort of disagree about PETN. I Find ETN more versatile and easily made. Its casting ability is probably its best aspect.

underground - 7-6-2019 at 07:37

I have both made and detonate ETN and PETN. From the 1st time i tested PETN, i have never made ETN again. I can achieve pretty high density with PETN by pressing it. It is more powerful and i got better yields from the same acids. It is not that hard to initiate by shock and it is more insensitive than ETN. I have calculate the cost of both ETN and PETN and despite E is cheaper than PE, it ends up PETN to be cheaper for me at least due to better yields.

For the casting ability of ETN, i never cast it because i am afraid a bit

Despite that, there is a topic about casting ETN/PETN mixture, it is even better than ETN itself, you should try it out.

[Edited on 7-6-2019 by underground]

Tkuze - 7-6-2019 at 08:55

Underground- I 100% agree, although I must add that I have observed several runaway pentaerithritol nitrations and only one with erythritol. Also PE is much harder to find and suspicious. Erythritol can be bought at yiur local grocery or health food store. Try melt casting. Its relqtively safe. Its been played with in molten form and its not super sensitive.

Tkuze - 7-6-2019 at 09:04

And yes, PETN yields are higher as well. Also ETN has a near 0 oxygen balence. I think its a very versatile, more available, easier compound in my opinion. Its RE factor and velocity is similar. The best way to play with it is to put like 20g in a pill bottle and heat in water bath at 70C until it melts ( takes some time), take out of the bath, let cool slightly until viscous and you can use a marker or plastic rod with the diameter of your Blasting Cap to make a cavity. Add the BC when ready to use and you can keep it in the pill bottle and fill the rest of the empty space with cotton or more 2°, or whatever the hell you want. Or you can remove and do whatever else you desire. The density of the MC is very high and avoids the risk ( albeit small ) with pressing.
Best use - wrapping your old college history notes and papers around 10g cast and watching it shred into a million pieces.

caterpillar - 7-6-2019 at 11:08

Quote: Originally posted by Tkuze

Best use - wrapping your old college history notes and papers around 10g cast and watching it shred into a million pieces.

Small piece of kalium picrate in your friend's cigarette.

XeonTheMGPony - 7-6-2019 at 18:14

Quote: Originally posted by MineMan

I don’t mean to be ignorant. But. Was Picric acid not an explosive of the very early 1900s, are there not better EMs with simpler OTC synthesis for us clandestine to semi professional scientist?

I feel like I am missing something about the excitement of Picric... can some please correct me if I am wrong? Is it merely a curiousity if not used for other EM synthesis?

novelty and an appreciation of Historic EM's

It was all so used as a burn dressing at 4% solution so it all so served as a ww1 medicine and dye

caterpillar - 7-6-2019 at 21:35

Quote: Originally posted by MineMan

The story of PA is really interesting. It was., of course, an explosive- no matter. if someone knew about it or not. It was used, yeah, as yellow paint and in medicine- to sterilize skin in surgery. Later it was used as explosive, but this usage met with real problems. PA is acid and makes dangerous salts of iron for example. Its melting point is 122 Celsius- a hot water bath cannot be used to melt it. When it freezes, it significantly decreases in volume, making cavities in shells. The inner space of shells had to be protected by pure tin without a significant amount of lead. Such pure tin was a problem. Some people died, performing corresponding investigations. You definitely have no idea about Panpushko- the Russian researcher, who died after an explosion in his laboratory. The Russian fleet was defeated at Tsushima and one of the reasons were shells- Japanese ones were more powerful than the Russian ones. Russian used pressed NC, Japans PA. NC is more powerful, but it can't be pressed to 1.7 kg per liter- only to 1.3. In shells, the volume of camor (the space for explosive) is strictly limited and explosive with a higher density is preferable. Well, later TNT replaced PA, but for us, PA is much better, It doesn't require fuming sulfur acid for preparation.

Herr Haber - 10-6-2019 at 07:15

Quote: Originally posted by Tkuze

Underground- I 100% agree, although I must add that I have observed several runaway pentaerithritol nitrations and only one with erythritol. Also PE is much harder to find and suspicious. Erythritol can be bought at yiur local grocery or health food store.

Chasing the runaway:
RFNA more yellow than red was used. It was slightly below 80%.

Under the same conditions on the same day with the same acids:
ETN went smootly between 5 and 10 Celsius.
1st PE ran away when I stopped paying attention for less than 5 seconds. I had to drown the mix.
2nd PE ran away while I was answering nature's call. It clearly showed it's intentions from the start so I was not surprised.

I agree with you 100 %

underground - 10-6-2019 at 11:59

I have never had any PE run away. I keep the temp below 10c when i add the PE, 15 minutes after the addition is complete i raise the temp to 60-70 slowly. Never had any issue and yields are pretty good.

Herr Haber - 11-6-2019 at 03:50

I was interested to see how the presence of NOx would affect the process and if it could be managed.

On the second try the runaway ejected part of the content on the beaker on it's surrounding. I am still wondering how the wooden counter was not affected (cleaned easily) and the plastic of one of the gel packs was covered in what has every appearance of white paint.

Back to picric acid, my opinion is that as an historical EM it is very interesting. Lots of data and stories about it.
Also, the three stage nitration teaches a lot and makes you think about what is going on and how to perfect it.

caterpillar - 11-6-2019 at 14:18

Once I got runaway, making NG. I was standing behind the door and waiting for an explosion. But it didn't happen. Back to picric acid, yeah. Nice compound for beginners. Ammonium picrate can be mixed with AN and used as a component of rocket fuel- 45% of AP, 45% of NaNO3 and 10% of some binder (epoxy for example). Kalium salt of PA burns quickly, leaving black smoke, but explodes, been ignited in confinement- it this case there will be very few smoke. PA is the precursor to DDNP. And it is the only my proposition, but a solid guess- 0.5 gr of lead picrate + 1-2 gr of pressed PA and you have a blasting cup.