Over the last couple weeks, I have taken an interest in producing my own hexamine. The precursors are cheap and not watched too much by big brother and the procedure is simple. I saw there are a couple old hexamine threads, but they were unorganized and offered conflicting opinions. I will post my lab notes from my experiments starting with the concentration of the ammonia solution. I also have a few pics I will provide along with some of these steps. Also note that all of this was done with OTC products. I will describe where and how I purchased all the materials used in the text.

I realize hexamine can be bought through ebay or chem suppliers. At first I just wanted to produce hexamine for the experience, but after determining that I can make 500g of very pure hexamine for about 6 or 7 USD, I decided it might be a better idea to make my own. This will also help avoid unwanted attention, as hexamine itself is a precursor to many drugs and, obviously, explosives.

For this lab you will need:

100mL 10%+ ammonia solution
50mL 40% formaldehyde solution
Beaker
Thermometer
Ice Bath
Hot Plate or some type of heat source
Lab safety (goggles, gloves, lab coat)

Hexamine is produced via the addition of ammonia solution to a solution of formaldehyde. It is important to use the most concentrated ammonia you can achieve, as this will have an effect on your yields. It will also decrease the amount of water you need to evaporate in the end and save you time. So first I will go over how I concentrated my ammonia. I should also mention that I received much information from Charles Owlen Pickett, who communicated with me through PMs to give me advice on how to perform this experiment. Thanks Charles :cool:

I started with household 5% ammonia solution bought for 2.99 per gallon at the local hardware store. Now the way to concentrate it is to bubble ammonia gas through the solution. The set up for this is very simple, as you can see in this picture (http://i164.photobucket.com/albums/u6/pudgedog69/DSC00215.jpg). You don't need a flask, just another bottle would work just as well. The polyethylene tubing was about 15 cents per foot. The whole setup would cost about 3.50 for the soda bottles, the tubing and the hot glue. The water bath is to keep the solution cool, as more ammonia will dissolve if the solution is cooler. Remember that with gasses, solubility goes up as temperature goes down. This is needed as the reaction in the flask is highly exothermic, which I will now discuss.

The contents mixed in the flask are anhydrous Sodium Hydroxide (NaOH) or what is commonly known as lye. This was bought at the hardware store for 3.79 per pound (454g) listed as a drain opener. Note that any metal Hydroxide can be used in this reaction. The other substance was Ammonium Nitrate. Now before you flip out, just hold on! The AN can be replaced by any Ammonium salt. Ammonium Sulfate, which is a very easily found and cheap fertilizer, can be found at most hardware stores in the spring. (EDIT: I just purchased 15 pounds or 6.8kg of AS at Steins Garden and Gifts for $12.06) I am awaiting my shipment of AS as I am too inpatient to await the spring to come. I found mine for 4.10 per 5 pounds on ebay. This is just one Ammonia salt that can be used, any others are acceptable. I chose Ammonium Sulfate due to the fact it has two ammonia groups bonded to one sulfate group, whereas many ammonium salts only have one. Just make sure to adjust quantities appropriately. When these two are mixed, a single displacement reaction takes place. *SEE NOTES AT BOTTOM*

NH4NO3 + NaOH ---> NaNO3 + NH3 + H2O.

This makes it pretty simple, as the molar ratio is 1:1. This would mean 80g of AN mixed with 40g NaOH would yield best results. You will notice that the resulting water will cause the mixture to clump. Just shake every now and again to loosen it when the reaction starts to slow down. In this reaction, you see that Sodium Nitrate is evolved! I need to find a way to extract it from the unreacted NaOH and AN so I can use it again... Also remember that this reaction is highly exothermic, so be careful with it and use an ice bath if you must.

You should notice gas start to bubble through the solution. Remember to check the bottle for excess pressure to ensure nothing explodes on you. If the bottle is gaining excess pressure, slowly open the top to relieve it. I found that bubbling 1 mol of AN and NaOH through 100mL of water yields a good percentage. 1/2 mol of each through 100mL yielded a solution that left quite a bit of excess formaldehyde after the reaction, which really stinks up the place when evaporating for your product. The yield was decent however, about 12g as opposed to the 15g achieved with the latter. If bubbling the 1/2mols per 100mL, perhaps 125mL should be used instead. More on that later.

Now that you have your highly concentrated ammonia solution, you are ready to add it to the formaldehyde. Formaldehyde is used to a great extend in agriculture. Therefore, it can be bought at many agriculture stores, for a cheap price. I found mine for 14$ per gallon, and they told me if I ever wanted it in 55 gallon drums, the price would be reduced to 6$ per gallon. I was only asked for ID when I purchased this. Remember that social engineering plays a huge role in obtaining materials without making people suspicious. Since the production of hexamine is not illegal, I went ahead and told them what I planned to do with it and gave them a little chemistry lesson. I think they were really amused and liked it.

Anyway, place 50mL of 40% formaldehyde in a beaker. Place that in an ice bath. Slowly add 100mL of your ammonia while stirring. Note that the ammonia will be in excess for this reaction. You will notice a large increase in temperature. If it gets too hot, sparks and smoke may result. After addition, stir well and let the solution stand for 24 hours. It is probably not necessary for 24 hours, but I do it to ensure completion of the reaction.

Note: When mixing with 5% ammonia solution, I noticed almost not rise in temperature. The yield was also horrible, barely any crystals to scrape off the side of the beaker. This shows the importance of having concentrated ammonia. The yield could have been fixed by adding much more 5% ammonia, but the evaporation that would have to be done later would not be worth the effort in my opinion. While evaporating the solution, it also smelt horribly of formaldehyde. So badly I had to go and get my gas mask.

After the solution has stood for 24 hours, get your hot plate ready. Your solution should still be crystal clear, as seen here (http://i164.photobucket.com/albums/u6/pudgedog69/DSC00217.jpg). Heat your solution to about 90*C and allow the water to evaporate. Note the only byproduct of this reaction is water. Seen below.

6CH2O + 4NH3 ---> C6H12N4 + H2O

There will of course be some unreacted products, so evaporate in a well-ventilated room or outside. When all of the water is evaporated off, you will be left with a cake of wet hexamine crystals. You can dissolve these again in distilled water or alcohol and recrystallize if you wish.

Place your crystals on a glass plate or something that can withstand heat in an oven. Put your oven to 100* C. Don't worry about the hexamine, it will only start to sublime at 280* C. When they have dried, remove them and allow the crystals to cool. You should have a product of nice white crystals, like this (http://i164.photobucket.com/albums/u6/pudgedog69/DSC00216.jpg). My yield from the quantities used in the above experiment resulted in 15g of hexamine. This is a picture of the hexamine burning (http://i164.photobucket.com/albums/u6/pudgedog69/DSC00220.jpg).

I hope this information was useful. If anyone else has had experiences with making hexamine or concentrating ammonia, I would love to hear it. Critism and corrections are welcome too.

NOTES:
*Remember that the two compounds being mixed (the hydroxide and the ammonium salt) must be in powdered form to achieve max surface area, resulting in a faster, more efficient reaction.

*I would also like to mention that ammonium sulfate, formula (NH4)2SO4, will require a molar ratio of 1:2, as sodium sulfate has the formula of Na2SO4. Sodium sulfate is actually a hydrate, which will absorb water and turn blue. This could be useful as it will absorb water from the reaction and the color may give an indicator as to how complete the reaction is. These are just ideas as I have not used ammonium sulfate yet. I'll let you guys know.

Wow this is great I've been looking all over for a detailed hexamine synth. Well written, good instructions, nicely done!!

Thanks alot for the information. And props to COP(Charles Owlen Pickett) for helping you. Sorry if the short title offends you or irks suspicion from others. Looks like you probably save heaps of money making it rather than buying camp stove fuel I get 77gs for ~5-7$ most likely it is. My friends uncle owns a funeral parlor and it services bodies there. I am going to mention my need for gallons of Formaldehyde for this purpose, hopefully he doesn't think I am nuts. lol. When people these days here chemistry or chemicals, they immediately think drugs, bombs terrorists. and that no person should be doing experiments at home , like why would they need to. :rolleyes:

I have a question though sort of off topic, you claimed the reaction was not illegal, is there a site where I can find information on what type of reactions are legal and what are not? Is it illegal to make black powder for instance. My main illegality question would be is it illegal to produce Nitrocellulose? I wonder because I know you can buy it as magicians paper or flash paper, but it is prohibitively expensive, something like 300$ for 30grams if I remember correctly... I actually do some "magic", I am starting out. So you can see why I would ask.

And as we all know just because you can buy something does not make it legal to produce. Thanks in advance.

I have a question though sort of off topic, you claimed the reaction was not illegal, is there a site where I can find information on what type of reactions are legal and what are not? Is it illegal to make black powder for instance. My main illegality question would be is it illegal to produce Nitrocellulose? I wonder because I know you can buy it as magicians paper or flash paper, but it is prohibitively expensive, something like 300$ for 30grams if I remember correctly... I actually do some "magic", I am starting out. So you can see why I would ask.

And as we all know just because you can buy something does not make it legal to produce. Thanks in advance.

I am pretty sure making homemade black powder is not illegal, at least not in the state I live, as such theres probably different laws for different states regarding blackpowder rather than heavy explosives with the federal government (thats how I understand it anyways, anyone feel free to correct me on that).

Anyway, Barnacles, there is a text file of a list of explosive materials that are regarded as "watched" by the ATF.

Included on this list is black powder based explosives, nitrocellulose, and HMTD (Hexamine being a common fuel for small stoves would obviously not be on the list, however, they probably keep a watch for large quantities of the stuff being ordered like they would anything else).

The ATF list file is outdated, but I don't think that would matter, if anything they have added material instead of taken anything off :( . You can get it on the FTP under "UPLOAD\Mr Science\The Disease FTP\Explosives\Law".

Hope that helps.

[The chemical watch list issue & the ATF are mostly contextual.] In that, there does not seem to be a great deal of intense scrutiny for Joseph Blow but if someone has caught their eye (ATF) for other issues then the list and chemicals, generally - make for a report within a report. This is often used to "prep" a case for the Prosecution & made available to the defense upon discovery. Juries like to ogle chemicals and the more they have, the more they have....it's show-biz for a court-room.
Unless you have a lab with drug precursor chemicals in it, there is generally little interest outside local fire ordinances.

Hexamine is a very flexible material and this lab illustrates how materials that utilize hexamine are VERY inexpensive from a manufacturing perspective. Often it's said how cheap RDX is....and you can see that with a production mechanism with a great deal of ammonia & formaldehyde; the stuff could be dirt cheap. No matter how you cut it, PETN will never have this inexpensive of a precursor, etc.

This is a valuable thread as it opens itself to a variety of synthesis of hexamine. It's also important to remember that no hexamine (or R-Salt) wash water / synthesis water) is ever wasted. It can always be evaporated and the last bit made available. There is very little waste in these synthesis!

Rbick - nice post; straightforward and simple, even for me who forgets everything...

One question however: as you spent the time calculating ammonia output from the NH4NO3/NaOH mix, why didn't you just bubble it directly through your formaldehyde solution?

This would mean less water to evaporate, a cooler reaction temperature and one less step.

(The ammonium solution concentration step could be useful for other reactions, of course)

Excellent idea! I never even thought about this. I would have to do some experimenting with it though to see how easy temperature is to control, ratios, ect. Anyone have any experience with this method?

NOW...YOU HAVE GROUND BREAKING STUFF AVAILABLE. I looked this up while I was reading it and couldn't find a thing on going direct. The only thing to do is try it! Keeping in mind molar ratios you may want to attempt a 50% level at starting. My reasoning is that the most common industrial ammonia is around there. Remember that you are dealing with a flammable material in this as there will be no water to minimize that hazard. Additionally you may want to keep temps within 80 C so you don't loose a yield to fumes.

Use a "deep" container; so as to allow fullest contact with the gas. Just as the best yield of Silver Acetylide is achieved with a deep flask or even test tube rather than a beaker you want contact with the gas to be as long as possible. You may even want to maintain a slow-bleed exhaust system to maintain gaseous contact longer, etc.

Yes, I will be trying this soon.

I should also mention the results of using Ammonium Sulfate. I mixed it with NaOH and no gas was produced. This was strange, because with AN, simply mixing the two solids resulted in ample gas production.

Without thinking, I quickly added about 10mL of water. Ammonia gas was VERY rapidly produced. I had to go grab my M-40 gas mask and run outside with it. Stupid I know, but the little added water started the reaction which continued through until completion. It seems the water is needed to "jump start" the reaction. Next time, I will try adding 1mL through an eye dropper and see how it works.

The resulting ammonia solution was highly concentrated, and I'm assuming is better than with AN/NaOH. The mixture also bubbled gas through the solution much longer than AN/NaOH. My molar ratios were 1:2 SA to NaOH and I used 66g/40g per 100mL of 5% ammonia solution. This may actually be too much, I'll calculate it and make a prediction later. I will also gather experimental results first, as those are obviously more trustworthy than theoretical :)

Rbick, fast moving today..

I'd wonder if some of the energy for the reaction came from the NaOH giving off heat as it dissolved, bumping the reaction temps up and speeding your ammonia production?

I had in my mind a setup with your flask - a outlet for the ammonia with tube, going into the formaldehyde solution as you have and an inlet with a funnel inserted. (Referring to your first posted image might help with the visuals here!)
The ammonium sulphate could be already in the flask as a solid and a sodium hydroxide solution could be poured in as required (ie as the production of ammonia slows). Note to anyone - perceived or real danger of overpressure in flask forcing caustic NaOH up and out of the funnel onto hands/into face of the operator before it completely drains into flask? Perhaps just removing the stopper temporarily and pouring in a small amount at a time would be sensible.

If I was to do it myself, I'd aim for an excess of ammonia to be made to allow for some escaping. Once the ammonia/formaldehyde reaction is complete, any excess dissolved ammonia should be dispersed while one evaporates the water.

I'm conscious of Charles' references to flammability and your own experience of the overpowering encounter with ammonia gas. Safety first and slow but steady gas production is likely good advice.

The above is all subject to hearsay as I have no hard facts to hand. Am tempted to go and establish some personally though. Open to comment.

I would prefer using lime - either Ca(OH)2 or CaO - for NH3 production. Due to ist poor solubility in water the reaction rate should be lower - especially when using (NH4)2SO4. Its low price is hard to top.

I'm not a chemist. Perhaps theres a downside unknown to me?

If lime is more accessible to someone, then yeah I would use it too. Solubility in water doesn't play too much of a role in the method that I use, I just need to add less water and at a slower rate to ensure my reaction doesn't run away on me and fill my house with ammonia gas. I may try lime however, as I believe I can get it for far cheaper than NaOH and in bulk. Thanks for throwing that idea out there.

There is actually a thread out there on the production of ammonia started by mega a few years ago. He does in fact mention Ca(OH)2 as being a good material to use. A quick search of the forum will find it. The only problem I can see is that since it has two hydroxyl groups, it will probably produce a lot of water byproduct, which could be detremental. But if you don't mind the extra water, it doesn't sound like a bad idea.

This post's heading is from a headline in the Health section of the March 25 NY Times, and they are talking about formaldehyde. Seems only industry people and forum members like the stuff.

"Formaldehyde" searches in Google tend to discover formaldehyde-free items. "Formaldehyde" plus "garden" doesn't produce much. It is not easy to find, so I appreciate the agricultural angle.

"Get it while you can" might be good advice.

I read that article. Carcinogen my ass, chances are they are just looking for a reason to ban it.

Unless you order from a chem supplier, chances are agriculture stores are the only place you are going to find formaldehyde. I'm going to find some Ca(OH)2 today btw :)

Exposure levels are basically the determinate of any level of toxicity simply be definition. Who in their right mind would would stuff a fucking panty liner with formaldehyde? Idiot hippies, would would ban water if given half a chance (through ignorance) vote in elections in Northern Kalifornia are responsible for this crap. But realistically, if a fume hood or other measures are being used that should not be an issue.

Formaldehyde IS really a very common chemical and it would impact our economy greatly if it were banned, etc. What generally takes place is that the targeted material is pulled from common domestic supply and the individual needs to find the industrial supply for purchase.

There is a very simple way to archive industrial purchase (PM me if interested). Once that is surmounted, the rest is a question of how much is needed and means to buy no more than necessary.....That is sometimes a real challenge. Unfortunately some of the best & most workable techniques were burned down by teens attempting a half-hearted version of the above. That is why (once again) I caution all of you, if you have some good sources, not to let them get into public domain.

Hi all,

Wouldnt it be much safer if I add some sand to the AN/NaOH mixture ,since the
reaction is exothermic (the name caustic soda scares me :o).

Next week I will try to synthesize some ammonia through dry distillation.
Formaldehyde (they call it formol) is very expensive here , 250ml for 3 USD :mad: (the same for ammonia) ,and since Ammonium Nitrate and Caustic Soda are sooooo cheap ,i think to make it by myself would be better for my pocket :D

What exactly is formaldehyde used for in an agricultural context??? I've NEVER seen it at Fleet Farm or the garden store, nor the feed mills and elevators where I get cotton seeds and rice hulls. But then I never asked for it by name either!

In fish farms, it is used to treat several types of fish scale disorders similar to "Ick" in an home aquarium. Often a variety of poisons are used for topically presenting disorders in veterinary medicine.

Where I am, farmers have lots of cattle. Formaldehyde is used in foot baths for the cattle due to its anti-microbial properties. Its sold in 37% concentrations.

Instead of venting off the ammonia gas if the pressure gets too much why not have multiple bottles linked togetrher so the excess from one is bubbled to the next. Fish tank bubblers could be used to give more surface area.

RBIK the formation of ammonia gas from NH4+ salt and a base occurs in aqueous conditions (in water). AN is very hyrdoscopic (absorbs water) which means when you mix it with the caustic soda there were allready NH4+ ions in solution to react with the OH-

Sulfate isnt as hydroscopic so would need water to make NH4+ ions avalable.

I have some experience with hexamine preparation. Be carefull not to heat it to much when you remove excess water (I even used rotary vacuum evaporator once and it works) since if you overheat that mixture hexamine decomposes.

Also in a completely diferent experiment I used ammonia generation described above and...well it works but it is a bitch. I had to use couple safety bottles in line since bubbling ammonia isn't that simple as it may look at the first look. My solution had constant wish to jump toward the ammonia reaction system through the pipes I used due to great hygroscopic properties of ammonia (I should probably use term "solvoscopic" since I used methanol solution but...).That reaction made me tired like nothing else since I had to take care of it and nourish it constantly.

I would like to use CaO or Ca(OH)2 but I fear that it will perform poorly since CaSO4 can trap Ca(OH)2 inside CaSO4 precipitate formed during the mixing inside ammonia generator.

I tested a similar method of producing ammonia using Ca(OH)2 and NH4Cl with small quantities heated in a test tube (0.005 and 0.01 mol respectively, bubbled into 100ml of water). As FUTI said, it's a bitch, and I wouldn't want to use this method for large scale production unless I had to- anyone doing this should seriously consider getting proper glassware if they don't already have any. I'd recommend a flask and tubing.

According to a test kit ammonia was present at 0.2%. Therefore for 50% concentration of 100ml, roughly 90 grams of Ca(OH)2 and 130 grams of NH4Cl would be required. As it's designed for aquariums, the kit may be inaccurate though.

Yes, I also agree totally with FUTI, since I've tried before making ammonia from slaked lime and (NH4)2SO4 grade fertilizer and the reaction was a real pain in the ass and very slow even if you add more water; After this painfull experiment I always used NaOH, even though is much more expensive than lime. However using AN (or other salt than ammonium sulfate) with Ca(OH)2 the reaction will be much easier, but you will certainly need add small amounts of water and heat the contents to speed up the reaction, otherwise dont spect any decent yield.

Also, like FUTI stated, the ammonia absorption in water can be cumbersome, since is so highly soluble in it that is prone to lower the pressure inside the apparatus, causing suckback which is part of the forming ammonia solution going up the NH3 tube and ending to fall in your generation vessel causing a great mess.. I have actually tried (2 years ago when I was still using PETE bottles and kid toys to build my home lab :rolleyes: ) to bubble ammonia directly in 37% formaldehyde solution , in a try to get less water to evaporate, like Oss wondered, but the end was that the suckback occurred even more fast.. What I think is that the suckback will be strong not only because of the great solubility of NH3 in water but in situ react with formaldehyde, what cause furter 'demand' of NH3, creating faster suckback; at other hand the heat generated during this reaction can counteract somewhat this suckback... So maybe would be a very good thing if you put a 'trap bottle' between the generator bottle and the absorbing one.. even better if instead you use tube directly in the solution you use an inverted funnel just a few cm down the liquid and that in a serie of absorbing vessels to dont lost too much ammonia..

Rbick: in the very first pic were you bubbling ammonia through a small PETE bottle? If yes, be aware, since PETE is prone to decompose to ammonium terephthalate and that not only may cause contamination of the aqueous ammonia but also erode and fragilize the bottle so your solution will go away through leaks created by the ammonia.. This last situation is much more prone to actually happen if you try to store your ammonia in it.

Anyway this is a very great work and certainly greatly help to people that actually dont have any OTC source of hexamine (like I), being the only real way make it from OTC precursors.

I have one other thing to add about generating a gas. Fact is that you could generate the gaseous HCl from NaCl and H2SO4, but you will always see chemist use H2SO4 and concentrated hydrochloric acid instead. That is enough to support my reluctance to use any system where phase separation can occur.

About suckback...does anyone know good way to prevent that...maybe some pump like does used for aquariums to generate constant overpressure?

There are many ways to deal with suck-back. For this situation I would suggest a simple intermediate isolation vessel (a flask trap along the gas line between the gas generating mixture and the solvent...)

I used three wash bottles in line as Duke proposed and I'm still unhappy with that solution. Maybe something like some of those anti-splash adapters used on rotary evaporator could do the job also?

I know the bubbling of air in hexamine synthesis reaction flask is bad idea as it could decrease the yield, but I'm not making that. That is why I'm looking into mixing the generated ammonia gas with other gas to produce a constant pressure stream. I guess that a mercury filled bubbler after the reaction flask can prevent the overpressure climb to a 3atm where my flask turn to shrapnel granade or maybe even before reaction flask attached sideways with T-type tube just in case. Any ideas?

I always have wondered if I could use other reagent than ammonia to produce hexamine with less cost. Also, in my country the strong ammonia is banned of the shelves, and very watched. The only thing that is sold to commom people is the shitty stuff, 2-4%, used with H2O2 to discolor hair(even this I noted disappearing of the market :mad: .. They clam that "it is too dangerous".. Like formaldehyde, it is only a poor excuse to remove it from OTC )..I have made hexamine with it before and is needed a lot of it. Its weird, but the hexamine yield based on formaldehyde seems to be really poor with these dilute solutions, as cited in this thread. Another reason is that absorbing ammonia in water isnt so simple, as also discussed here.

So I was wanting a way to generate NH3 in situ with the formaldehyde to produce hexamine. I based this in the fact that in some synthesis the hexamine appear to be really made in situ, needing only anything that can drift to right the possible equilibrium .. One of these is HMTD preparation with (NH4)2SO4, that was the original synthesis of it (IIRC). The way I encountered was to dissolve (NH4)2SO4 in formaldehyde solution, the add a thing that binds to sulfate and which could be removed with relative ease. Two years before I used slaked lime and very raw materials (brown fert. grade ammonium sulfate, with iron). Today I tried to repeat this experiment, but with some more care (In advance you will see that I still wasnt that patient :cool:) and more pure reactants. I also replaced the slaked lime by CaCO3 which was a byproduct of sodium sulfate production using frogfot method, described in his page. I used it for several reasons: seems to be much better than lime (slaked lime usually contain Mg(OH)2 and other things that sucks, and also appear to be more "bulky", what means more mess); CaCO3 is much less soluble than Ca(OH)2, so any excess of the first will probably not be a problem; and also I was using CaCO3 since I was wanting to just put it in a good use :) ..The only drawback is that CaCO3 will cause foam and this isnt good to be done with a stinky substance like formaldehyde. Also, my CaCO3 actually contain a small amount of CaSO4, from the procedure I made it (from plaster and Na2CO3 in water), but I dont think it being actually a problem. The ammonium sulfate and CaCO3 were used in excess of theory , especially CaCO3.

But anyways I plan to still repeat it , with more care and patience, until works, in some way or other.

6 CH2O + 2 (NH4)2SO4 <----> 6 H2O + 2 H2SO4 + (CH2)6N4

CaCO3 + H2SO4 ---> CaCO3 + CO2 + H2O
----------------

6 CH2O + 2 (NH4)2SO4 + 2 CaCO3 ----> (CH2)6N4 + 8 H2O + 2 CO2 + 2 CaSO4

82mL of 37% formaldehyde was measured and placed in a 500mL polypropylene kitchen cup. 50g of pure (NH4)2SO4 was measured and mixed with the formaldehyde in the cup, until almost all dissolved. 50g of dry and fine powdered homemade CaCO3 was slowly added and strong swirling to avoid any CaCO3 clumps and excessive foaming in solution. Initially the CaCO3 reacted nicely , but the formaldehyde started to goo too much and become yogurt like, difficult to swirl.. This seems to be para-formaldehyde forming, so I added the contents in a bigger container (3 L plastic bottle) and more 400mL of water added (part of this used to remove the rest of the goo from the cup). In the much less viscous liquid, CaCO3 was slowly added with the same strong swirling and reacted nicely. Until all the addition (that tooks 10-15 min), the smell of formaldehyde become weak. More 20g of CaCO3 was added and then more 10g of (NH4)2SO4. Finally, after swirling the contents for some minutes, more 10g of CaCO3 was added and the container swirled for more 2 mins. During the slow additions the liquid did not appeared to be visible warm at any momment. The lid was loosely put on the container and the milky liquid was left to stand 30 mins..When I opened the container a noticeable smell of ammonia comes, what is a good indication. Then was filtrated using a square piece of synthetic cloth.. Then the cloth with CaSO4/CaCO3 was squeezed by hand to free most of the intersticial liquid, then some water was added to the improvised filtrating cloth to extract the rest left.
The liquid was filtrated again using two coffee paper filters and some cotton stuffed in a 1,5 L vol polypropylene funnel. The filtrated liquid was pale blue. I'm almost sure that this is due of the synthetic cloth I was using, that is blue. Weird that the ammoniacal solution just leached some of the dye. Next time I will use other thing to filter.

Anyway I was wondering that if I add HNO3 to this solution, some HDN ppt out.. So I added 40g of KNO3 to 65mL 30% HCl and plus 45mL water and mixed for some minutes until almost all dissolved.. The KNO3 was very slow to dissolve, even though the solution wasnt apparently very cold. Next time I will try NaNO3 or NH4NO3.

I added this to the pale blue liquid obtained before, without any cooling since I was without ice (again: patience usually isnt my strong point), expecting any HDN ppt, even in small amount, but instead a unknow pale white smoke was produced and the pale blue color disappeared, giving a clear solution.

Failure.

Do you guys think that if I modify my procedure I will get anything good?

I just thinked about HDN since might be a way to see if hexamine is present ( I hate evaporate solutions to dryness and all that involves liquids being heated for more than some minutes. hahaha).

FUTI, I like your idea of using aquarium pump to generate constant overpressure.. Mine is small and rated at 4 L air/minute, but that probably isnt enough to water hungry ammonia...Maybe more similair pumps together to give more air..What you think?

Well, I just repeated the experiment I did, more two times, modifying it a bit.
In these two new tests I just used the same amounts of reactants [ CH2O (82ml), (NH4)2SO4 (60g), CaCO3 (80g) ] and changed a bit the other reactants ; the goal was to use the minimum amount of water and have minimum liquid loss (this unfortunately I still dont reached a good way).

second test:
The formaldehyde was mixed with 100mL of water in the 3 L container and in this was added the ammonium sulphate, all at once, and well swirled for one-two minutes until almost all dissolved. So I started to add the CaCO3, in the same fashion I did before. All was did in backyard.

After all the CaCO3 added, the mix was left stand for 15 mins ; then most of the goo was filtered through a simple coffee filter paper, and the filter was slow and cautiously squezeed to not leak. The residue was put back in the 3 L container and 70mL of hot water was put in and well mixed and filtered again using other paper filter and added on it slowly more 30mL of water and finally the filter was squezeed. The filtrated liquid was still with some insoluble matter so I used another fresh filter and filtrated again. The resulting liquid was clear and I measured as ~221mL (basing in formaldehyde + water total volume, about 61mL was lost.. Probably the most part of this the CaSO4 grasped forming the dihydrate). This was put in a bucket with ice/water.

At same time ~65mL of 30% HCl was measured and in it 40g of NH4NO3 was added.. It not dissolved very fast , even with stirring, and gaves a repulsive smell, mist of HCl and chlorine (as in homemade aqua regia! :rolleyes:) , so I added 50 mL of an OTC brand of muriatic acid, market as 10% HCl but this did not seem to help too much, so I added 50mL of water. With this the AN dissolved quite fast. Then the glass container with this mix was put in another ice/water bath.

After 30 mins the temperature of contents of both containers was 0-5°C. I added the cooled HCl/AN mix , all at once, to the cooled 'hexamine' solution.
Nothing really interesting happened.

FAILURE AGAIN; at least a very very small (even difficult to see well) amount of crystals actually have formed in solution and quickly redissolved, this was or was not HDN, I really cant say.

============================================

The 3rd test was done today and in this, the total final water was further reduced by simply dissolving the ammonium nitrate in the 'hexamine' solution rather than in HCl, then adding this, straight concentrated HCl, directly in HMTA/AN solution. Both solutions well cooled by a good salt/ice bath, rather than ice/water bath.

re-typing some parts from 2nd attempt, since this one is fundamentally the same I used in the above test, but with some minor modifications far than cited:

The formaldehyde was mixed with 50mL of water in the 3 L container; and in this was added the ammonium sulphate, all at once, and well swirled for one-two minutes until almost all dissolved. So I started to add the CaCO3, in the same fashion I did before.
This time I tried to use less water (50mL instead of 100mL used in 2nd attempt) to dilute the formaldehyde in an attempt to reduce still more the final water content, but this wasnt so good since the mix started to become very viscous and foam much more difficult to break down. So I added more 30mL.. But even so I needed to add more 20mL.. So I ended with the same 100mL of the 2nd attempt and this amount appear to be the approx. minimum with 82mL formaldehyde to give good (less) viscosity of the mix. Maybe using larger volumes of reactants the water ratio needed may be less.
All was did in backyard.

After all the CaCO3 added, the mix was left stand for 15 mins ; then most of the goo was filtered through a simple coffee filter paper, and the filter was slow and cautiously squezeed to not leak. The residue was put back in the 3 L container and 60mL of hot water was put in and well mixed and filtered again using other paper filter and added on it slowly more 30mL of water and finally the filter was squezeed. The filtrated liquid was still with some insoluble matter so I used another fresh filter and filtrated again. The resulting liquid was clear and I measured as ~186 mL (basing in formaldehyde + water total volume, about 86mL was lost.. Probably the most part of this the CaSO4 grasped forming the dihydrate). But comparing with 2nd attempt this liquid lost was much more severe, Maybe partially is because I added portion wise water to dilute formaldehyde instead of adding straight 100mL (???), or just something goes wrong and I was not too cautiously like in 2nd attempt . This was put in a bucket with salt-ice bath, and 40g NH4NO3 added in the 'hexamine' solution, quickly dissolving and helping to lower the temperature of the solution still more quickly.

At same time ~65mL of 30% HCl was measured and put in a glass cup with a plastic lid and this was put in another salt/ice bath.

The temp. of both solutions after 20min was below 0°C (-10°C for HCl and -15°C for HMTA/AN mix). The HCl was then added , all at once, in the HMTA/AN solution (standing on the salt-ice bath) and immediatelly a white smoke comes from the container (probably, at least in part, this smoke could be NH4Cl formimg in air inside the container, since the HMTA/AN have a weak smell of ammonia and almost no bubble in solution was noticeable).

At the start nothing more than the smoke formed, and I was considering this a total failure. I just have left standing on the salt-ice bath 2-3 mins and then, for my surprise, small brilliant crystals started to appear. After more 1-2 mins the container was with a good amount of the white ppt; I then let on the salt-ice bath for just more 5 min and then filtered, washed on filter, with 50 tap water. Then put the funnel with the paper filter/ppt on another flask to receive the ethanol which was the next step (I always use 'waste' alcohol, like in this procedure, in my alcohol burner, just to save a little more money ) . 70mL 92% ethanol was added slowly and then 50mL of anhydrous ethanol. The filter was squezeed and the ppt is drying under incandescent lamp now.. They look like HDN (since I have made it before), nice shiny white crystals. =]


The most weird part, definatelly, was that these crystals took a time in solution before forming and precipitating.. When I made HDN these crystals formed in solution almost instantaneously! But this may be just the time of the HCl displacing NH4NO3 in solution , since in my commom HDN preparations I use Mr. Cool method in which nitrate dissolved in HCl.

If my precipitate is really HDN I will be just amazed! An OTC route to HDN that does not require HNO3 nor hexamine as direct precursor ! And this last in turn not requiring ammonia to synthesize it! I dont know if a member here made this procedure before, if yes, tell me here (PM me, if you prefer)!!! Also, if any member is going to test this, please lets all of us know!!! "quick 'n' dirt" way to HDN :D

Before euphoristically confirming the abovementioned, the next obvious things which I will do is to see if is really HDN (burn test/ detonation) and reporting here.

I dont know how much was produced and the respective overal yield, though. Also, my scale isnt that great (500g range kitchen scale), and so not very accurate..

So, to become more 'in tune' with the issue of this thread I will do the most obvious thing, which is trying again the procedure, but evaporating the solution to dryness to see if hexamine was really formed and purifying it, if necessary to remove any impurity calcium salts or other crap.

I just did a very quick search to see info on hexamine solubility in water, ethanol, etc..This will be useful to my next experiments and may be also with the issue of this thread..

From Seidell (grams per 100 grams solvent):

water : 81,32g (12°C ... This source seems to be wrong, by a zero: http://www.sinachem.com/hexamine.html )

anhydrous alcohol (does not say what alcohol, but I just guess, the author is reffering to ethanol): 3,22g (12°)

chloform : 8,09g (12°C)

100 cc of 90% alcohol : 12,5g (15-20°C)

Have anyone real good data about solubilities of HMTA or a 'magic' link to it ?

Thanks!!

EDIT: One thing I forgot to mention is that all the left over liquids ('hexamine' + nitrate + HCl) after some hours have a very strong smell of formaldehyde. Since hexamine and compounds (HDN, etc) tends to decompose in water (especially acidic solutions) to give up formaldehyde..So its another , but not very accurate, indication..

The almost dry powder have a weight of about 15g.

I did the burning test now and I fairly certain that is really HDN.. Burns with ease and giving a smell similair of burning hexamine. Tomorrow I will try to detonate it.

Formaldehyde isn't hard to find due to it's dangerousity because of junkies and terros, but to it doesn't have everyday commoner purposes. Shops doesn't keep in shelf stuff that anybody usually buys in quantities smaller than container.

I have my own "common supplier" which sells very wide category of chems, including stright from shelf substances like picric acid. :eek:

I'm going to make hexamine by myself, even if there are many suppliers, including my own which sells it even relatively cheap (15 euros/kg); I JUST recently bought HNO3&H2SO4 from them and their eyes would blink of explosives warning if I suddenly come back asking for some hexamine and at this, I really can explain them where I need ammonia and formaldehyde, but no idea with hexamine but RDX.. :confused:

Oh by the way, is it phossible to use paraformaldehyde in hexa synthesis?

I think I remember reading a post in one of the hexamine threads about someone using paraformaldehyde in the hexamine synthesis. From what I remember, it worked but the yield was a bit lower. Don't take my word for it though, I know it is in one of the hexamine threads on the forum here. Is there any particular reason you want to use paraformaldehyde, or are you just curious?

I used some (20g) of my homemade hexamine a few days ago to make a batch of HMTD. The product turned out great. It is kind of a sense of pride making energetics from homemade materials. You really get to to see the fruits of your labor, marked with a big BOOM! Sorry, had to brag a little ;)