[gong]

Hello everyone,

I'm new here, I want to ask how to make saltpeter or KNO₃ at home.

Substantively, I have read to make it ,but it's need cow manure as the material, I
don't have cow manure and I difficult to get it,

Can I use another material to substitute the cow manure?

And please tell to me how to make it step by step and if not objection,
please give me an example in picture.

Please someone tell to me 

Thank you very much

[vmelkon]

It depends on your starting materials.
If you had Pb(NO3)2 and some K2SO3, you just make a solution and mix them. PbSO4 would precipitate and the KNO3 remains in solution.

If you want to make it from natural sources, you can pass high voltage through air. This would form NO and other oxides of nitrogen.
The NO combines with O2 to make NO2. Bubble the NO2 though water to have nitric acid.
Add KOH or K2CO3 or KHCO3 to the nitric acid and you'll have KNO3 in solution.

Don't attempt it if you don't have the equipment or knowledge in chemistry.

[Borek]

In most cases it is much easier to buy than to make.

[Zerm]

I would imagine most any decaying organic mater would generate enough nitrates to be a suitable substitute for manure.  Think compost.  The wood ashes are the key source of potassium salts in a nitre bed.  Most traditional methods, of which there are plenty online, call for straw to hold in moisture and for the whole mess to be soaked with urine.  The nitre bed should be covered to prevent rain from leaching out the salts.  The whole process can take over a year and then there is the tedious process of purifying the potassium nitrate from all the other garbage.  Its incredibly involved but the instructions are out there and its a time honored, though quite archaic, method.

[billnotgatez]

I often thought if I put my chemical mind to it that I could enhance the old process so the production was timelier.
Oh well when I get some time.

[zaphraud]

most any decaying organic mater

If you want to accelerate this with an easily removed reactant, I recommend titanium dioxide (preferably anatase) and UV illumination.

[Benzenelover]

If you want to make it from natural sources, you can pass high voltage through air. This would form NO and other oxides of nitrogen.
The NO combines with O2 to make NO2. Bubble the NO2 though water to have nitric acid.
Add KOH or K2CO3 or KHCO3 to the nitric acid and you'll have KNO3 in solution.

Don't attempt it if you don't have the equipment or knowledge in chemistry.

There's a similar process to this one that involves mixing fertilizer and a strong acid (HCl, H2SO4, etc..) with copper, and bubbling the NOx through water. It'll probably be highly contaminated, but it can probably be distilled and reacted with Potassium Hydroxide (KOH) or potassium bicarbonate (KHCO3) to make some potassium nitrate.

I'd also like to note sodium Nitrate (NaNO3) is pretty similar for a few applications, such as pyrotechnics, and the hydroxide or carbonate salts of sodium are much easier to obtain than hydroxide and carbonate salts of potassium.

[Benzenelover]

you can pass high voltage through air. This would form NO and other oxides of nitrogen.

Also, this bit of the post caught my interest. Since I can't send a PM, I figured this would be the best place to ask. At what voltage would this reaction occur? Are there any side reactions? Should I consider the anode and cathode material? and about how much NOx does this yield?