[shrek1971]

Hi everyone,
I only have grade 12 chemistry and it has been a while.  What I want to do is extract potassium nitrate out of a water soluble fertilizer solution.  I want to make my own black powder.  Is there a way I could grab something around the house or easily access to create a precipitate to get rid of the phosphoric acid or could you suggest an easier process to get the potassium nitrate?    Thank you for any feed back.
Shrek

[Scratch-]

I wouldn’t mess with gunpowder in any amounts larger than what you can get from small fireworks, even then it can blow fingers off easily. Making gunpowder is dangerous even if you know what your doing. If you are knowledgeable enough to know how to make gunpowder you should know that forums won’t list details if their admins are worth a grain of salt (The people here are worth several tons of salt  ). I know this sounds like a lecture but I've had some close calls and know some people that have been hurt by fireworks.

[chemicaldream]

I can't blame someone for wanting to make blackpowder; I used to make it while I was in high school, and put a fair few craters in the backyard. And besides, even though many people will tell you not to do it, you'll still want to do it, so...

If you do, a) don't mix more than say, a few teaspoon's worth together at a time. b)Once you have made it, use it. Don't store it.
c) Do not use anything metal. Metal causes sparks (you don't want sparks)
d) grind up your ingrediants seperately, then mix carefully without scraping it.

As for  your Potassium Nitrate from phos acid, I'm not sure you're looking at the right chemicals for that purpose. Try looking for some way to mix another nitrate with a potassium compound. That should give you a displacement reaction and give you what you're after. (I used to buy Potassium Nitrate from the chemist)


Cheers

By the way, what source did you get the PO4 from? I've heard it's used as a PH adjuster for plants, and I know it's in softdrink.

[hmx9123]

Just a few things:

1. Black powder is not gun powder.  The brits call them the same thing, but here in america, black powder refers to the tri-component mix based on saltpeter, and gunpowder refers to smokless powder.

2. Most salutes (the exploding fireworks) don't contain black powder.  They contain flash, a completely different mixture all together.  None that I know of use smokless.

As for your own black powder, I don't think that this group is really meant to discuss how to make it or where to get chemicals; if you want to ask other questions related to properties, history, etc., then it's OK, but the rest probably won't be answered.  Now, if you're into your own amateur fireworks, etc., then the place to go is the usenet newsgroup rec.pyrotechnics.  Many of the people there make their own black powder.  But don't just take their word off of usenet how to do it.  Ask the people there for references, actual print books that talk about how to do exactly what you're asking for.  I know for a fact that these books are out there and reliable because I own several of them.  If you're making BP for your own fireworks, just make sure you're being safe and legal about it.  Making fireworks in a state without an amateur exemption is asking for it.

In case you don't know where to find rec.pyrotechnics, go to google, click on the 'groups' tab, then skim down to the rec.pyrotechnics group.  Search through their archives or post a new thread.

[chemicaldream]

hmx9123, you're absolutely right.

Black powder (and the actual nitro/guncotton based gunpowders in use today) is not something to be taken lightly. Yes, the information you require to make the stuff is out there, but the source/s that provide the basic informaition for making of it won't necessarily tell you of the precautionary measures required.

Chemistry has many facets of interest. If you just want to make loud noises, then perhaps look at the aforementioned pyro group. But do your research, or pay the consequences (you can't do much without fingers/hands/eyes) - it is easier to hurt yourself than you are aware.