Sciencemadness Discussion Board

Isolation of KNO3 from Urine

R0b0t1 - 17-1-2010 at 01:07

(In response to the thread found here: as I imagine this is a tad offtopic from it, otherwise I/someone else will just paste this as a reply to it)

Thank you for the method you illustrated, I've yet to try it out, but it is certainly more workable for me than the other method, as nitric acid is beyond my reach (until I get more sulfuric acid and some potassium nitrate).

Pity we've got only one hydroponics/farming/gardening place, and he won't sell me fertilizer as I guess I look suspicious. I first tried to buy potassium nitrate as fertilizer, then urea.

Given that the salts *will not* dissolve in ethanol, how might one then go about collecting KNO3? I've no idea what salts are mixed with it, and I don't happen to know enough of the compounds in there to really articulate something, but I would imagine the majority of the salt compounds would be KNO3, due to various methods of collection I have already read. These methods involve collecting earth which has been repeatedly urinated on, and boiling it. I do, however, wish to get urea and nitrate from my urine (as to save time). Would I be able to, as I said, collect the undissolved-in-alcohol portion, or would I need to mimic something which occurs in the ground?

hissingnoise - 17-1-2010 at 07:28

Pity we've got only one hydroponics/farming/gardening place, and he won't sell me fertilizer as I guess I look suspicious. I first tried to buy potassium nitrate as fertilizer, then urea.

Getting usable amounts of KNO3 from urine is hot, smelly and tedious work.
It would be a lot easier to make yourself look less suspicious or get someone else to buy the stuff for you.

hinz - 17-1-2010 at 10:03

In case you speak german, I can send you the book "Schwarzpulver für survival". The book isn´t very scientific, but it explains the medieval potassium nitrate production process fairly well. In the Middle Ages this was the only method of KNO3 production for gun powder, as the oxidation of NH3 to NO2 wasn´t invented yet.

Basically you have to fill a big bowl like a bathtub with earth and alkaline material like potash (K2CO3) or chalk (CaCO3) and then eat lots of proteins every day (you metabolize them to urea). Then you pee inside the bowl every day and wait. It´s important to make the bioreactor permeable to air, as the bacteria require oxygen to oxidize ammonia/amine to nitrate.

Additionally you can try to add amine containing material like fertilizer or ask a nearby farmer if you can have a bag of liquid cow excrements for your nitrate reactor.

After a few weeks the contents of the bioreactor are extracted with hot water.
As said before, it´s probably much simpler to make to isolate KNO3 from any nitrate fertilizer. But in case you choose the biological nitrate production, please keep record of it and upload them.

[Edited on 17-1-2010 by hinz]

densest - 7-2-2010 at 15:30

Somewhere on this site is a posting containing reports of experiments in France just prior to the invention of the Haber process. They found that the medieval method could be greatly improved by dispersing the source material on a support medium which allows a lot of air to flow through, such as sphagnum moss. IIRC, a mixture of sphagnum, earth, and urea/ammonia-containing material kept loose and moist was many (100?) times more productive than any solid or liquid mass.

Sphagnum moss is very inexpensive and available at a gardening store and is utterly ordinary attracting no attention. I suspect that the French method is a lot less smelly than the medieval one - more of the offensive compounds are oxidized quickly.

If the local fertilizer suppliers won't sell you nitrate or urea, there are a couple of alternatives for getting urea and then using the biological process... urea is not considered hazardous anywhere I know of and can be shipped through the mail, and if that is not possible, "instant cold packs" used to contain ammonium nitrate, which has mostly been replaced with... urea! Expensive, but available at almost any drug store/chemist shop/pharmacy. No stench when converting pure urea to nitrate, too.

[Edited on 7-2-2010 by densest]

Lambda - 7-2-2010 at 17:00

Quote: Originally posted by hinz  
In case you speak german, I can send you the book "Schwarzpulver für survival". The book isn´t very scientific, but it explains the medieval potassium nitrate production process fairly well. In the Middle Ages this was the only method of KNO3 production for gun powder, as the oxidation of NH3 to NO2 wasn´t invented yet. ...

Here you are @R0b0t1, and this is the book that @hinz was referring to:

Schwarzpulver für Survival - Alles über Schwarzpulver Chemikalien-Raketen-Zündschnüre-Sprengpulver - Von Manuel Baetz (2001) in German


Brisante Sprengstoffe
Die Stärke
Marcus Graecus
Schwarz & Co.
Die Chinesen
Entwicklung des Pulvers
Das Körnen
Die Stampfmühle
Kollergänge oder Läuferwerke
Die Improvisation
Schwarzpulver Classic (Nass)
Das Verfahren
Schwarzpulver Classic (Trocken)
Das Verfahren
Schwarzpulver Spezial (Nass)
Das Verfahren
Schwarzpulver Spezial (Trocken)
Schwarzpulver ohne Kohle & Schwefel
Das Verfahren
Theorie der schwefelarmen Pulver
Trets' Sprengpulver
Einige Alternativ-Mischungen
Martinsens Neues Sprengpulver
Brise-Rocs (Patent von Robaudi)
Carboazotin (Patent von Soulages/Cahuc)
Pyrolith (Patent von Wattlen)
Pochs Sprengpulver (Pudrolith)
Salpeter Generator
Das Verfahren
Die Dünger-Methode
Das Verfahren
Der Weg zum Salpeter
Das Verfahren
Chemische Betrachtung
Holzkohle #1
Das chemische Prinzip:
Das Verfahren
Rübenzucker (C12H22O11)
Das Verfahren
Ahorn- und Birkenzucker
Milchzucker (C12H22O11+H2O)
Das Verfahren
Das Verfahren
Die "Destille"
Die Papierhülse
Das Verfahren
Kleister Improvisation
Die Raketen Ramme
Das Verfahren
Das Treibmittel
Das Füllen der Hülse
Das Modell
Die Eissprengung
A . Feuerwerkerei, Pyrotechnik.
1 . Schwarzpulver (mit Kalisalpeter)
2 . Salpeterschwefel
3 . Grauer Satz
4 . Faule oder matte Sätze
5 . Treibsätze
6 . Funkensätze
A. Auf die Zusammensetzung bezügliche Patente.
B. Auf das Herstellungsverfahren bezügliche Patente
Chemische Analyse
Giftigkeit der Gase
Die Mörserprobe
Benutzte Quellen

Schwarzpulver für Survival - Alles über Schwarzpulver Chemikalien-Raketen-Zündschnüre-Sprengpulver - Von Manuel Baetz (Survival Press - 2001) 167s.pdf
Schwarzpulver für Survival - Front Cover.jpg Download Link (1.64 MB):

No Password Required !

Enjoy !


bbartlog - 7-2-2010 at 21:12

Just a short report of a negative result in trying this, with a couple of observations that might be helpful:
I made a small nitre bed using an old flowerpot - terra cotta, 14" tall, plugged at the bottom. I filled this with mostly mushroom manure, mixed with some earth, dried grass, and two pounds of magnesium carbonate. Over a period of six weeks I added about 30 liters of urine, aerating/turning every week; then kept it damp for two weeks (still turning it), and finally let it dry for a couple of months. Finally I poured six liters of boiling water through it (split into portions), filtered and boiled down the resulting brown solution.
No nitrates are evident. I currently have 150ml of very dark brown solution and no crystals have formed from it; the upper bound on possible nitrate content is low. Earlier tests on a small portion, using Na2CO3 (which should precipitate any iron or magnesium nitrates as carbonate) showed nothing either.
I'm pretty sure that either a month is not long enough to develop a robust culture of nitrobacter/nitrosomonas, or (more likely) something more basic than magnesium carbonate is needed in the nitre bed. Historically lime was used, and I believe this is in order to prevent ammonium nitrite from forming and quickly decomposing into air and water.
Also, if doing a small experiment like mine it might be wiser to not use a terra cotta pot, as the porous wall may be able to sequester (proportionally) a large amount of the compounds you want.

not_important - 7-2-2010 at 23:13

It generally takes some time for the nitrifiying bacteria to build up their population, so it may be better to start with a less rich medium and increase then build up the ammonia salts concentration.

The alkali used was more to combine with the acids formed, keeping the pH within the range preferred by the bacteria, and to form an easy to isolate salt, than for any protection of nitrate from further reaction.

Nitrate will be fairly stable so long as the conditions are on the aerobic side, if they go anaerobic then nitrate becomes a source of oxygen and gets converted to N2.

The conversion of ammonia to nitrite and nitrate decreases the pH, thus an alkali is needed to prevent the conditions from becoming too acidic; at the same time strongly alkaline conditions also inhibit the growth of most of the types of bacteria wanted.

The concentrations are fairly low, often the medium was arranged in long heaps aligned so prevailing winds would blow over them. This evaporated water from one side of the heap, liquid would be wicked in from the moister portions only to evaporate in turn. The dissolved salts were left behind, eventually a crust of nitrates would form. Fresh material - manure, urine, plant matter - was added on the other side of the heap. On a smaller scale something porous like a terra cotta pot would work well, evaporation would take place from its surface with the dissolved salts eventually forming a layer on the outside; the porosity also helps keep the contants aerobic. Patience and maintaing the proper water content is needed.

It's a slow, smelling, dirty, and somewhat frustrating method of obtaining nitrate, and well demonstrates the common problems with biological methods of production.

Aqua_Fortis_100% - 8-2-2010 at 06:29

I have not yet tested any of these ideas (the only thing I actually did was extracting urea from my urine, as by chemoleo thread.. was a fun, but very time and energy consuming process), but Im more and more interested in do a improved nitrification process, just for fun, since nitrate fertilizers are fairly cheap.

If the trick is good aeration of the very porous wet mass Im thinking to use a bucket half way full with sphagnum moss + some dirty bacteria containing earth + CaCO3 or slaked lime + agricultural urea/ some dilute ammonium sulfate in dilute solution. In the bottom one could attach a small low speed/low power motor (maybe a microwave plate motor) adapted with scoops/rakes which constantly stirr the porous mass while it receives the air flow from one or more aquarium pumps through the lid of bucket, that is used not only to help in avoiding evaporation, but also keep the mix from sunlight, rain and strange things falling in the bucket.

Im thinking ins using very dilute solution of comercial urea because urine contain a lot of salts (especially NaCl) that will difficult further purification process.

There is also a interesting quote from the book on SMDB library "industrial nitrogen compounds and explosives" :

Thus Muntz and Laine {Cowpf. rend., 1905, 141, 861 ; 1906, 142, 430, 1239) impregnated peat with sufficient lime to combine with the nitric acid formed, and then inoculated it with nitrifying bacteria and passed through it a 0.75 per cent, solution of ammonium sulphate (NH4)2S04, at 300 C., thereby obtaining a I per cent, solution of calcium nitrate, Ca(NO3)2. The bacteria would oxidise quickly only dilute solution of ammonium salts, but even 22 per cent, nitrate in the solution did not interfere with the process. Consequently, by sending the ammonium sulphate solution five times through the peat beds there was finally obtained a solution containing 41.7 g. of Ca(NO3)2 per litre.

Yield.— 6.5 kg. of Ca(N03)o in twenty-four hours per cubic metre of peat. The old saltpetre plantations yielded 5 kg. KNO3 in two years per cubic metre.

bbartlog - 8-2-2010 at 10:09

'passed through it a 0.75 per cent, solution of ammonium sulphate (NH4)2S04, at 300 C.'

Um what? 300C? Typo? Would surely kill the bacteria.
Also I think there must be some additional details missing. One pass with ammonium sulphate solution would result in the formation (from reaction with the lime that was added) of ammonium hydroxide and calcium sulfate. There wouldn't be any way to send ammonium sulfate through five times unless
- the ammonium sulfate was added stepwise
- the lime was added stepwise
- the degree of mixing was such that the ammonium sulfate and calcium (hydr)oxide didn't have opportunity to react fully
Of course, they might have sent the solution through five times even though the vast majority of the sulfate had been sequestered on the first pass.

not_important - 9-2-2010 at 00:16

Maybe not a typo but a common problem when copy-pasting text with special symbols. Likely it was 30<sup>0</sup>C

Also, in texts older than say 1950 you need to keep the following terminology in mind:

Ca(OH)2 = slaked lime
CaO = quick lime
CaCO3 = lime or limestone