Problem with Hi-Yield potassium nitrate--help a noob

[dom]

I'll start by saying that I'm new to pyro stuff and this forum.

A few years ago I got a bottle of hi yield prills that worked fine (after I ground them). Then recently, I got a bottle of hi yield powder that will not do anything.

I got some spectracide to compare and the spectracide works just fine.

I already tried baking the hi yield, that made no change.

I put some spectracide and some hi yield directly in a fire: the spectracide made the wood burn bright white once it got going, the hi yield just sat there.

It wont do anything with sugar rocket fuel or in black powder.

 

On the MSDS for the hi yield it says potassium nitrate and nothing else.

I cant figure this out. Is there something else they put in? Has anyone else encountered this?

Thanks,

dom

[davidh]

Try crystalizing a small amount of it and see if it forms KNO3 crystals. It may be impure, perhaps purposefully impure. Crystalizing is a very good way of purifying KNO3, more so than most salts, given its solubility curve.

 

That said, just buy it from a pyro chemical vendor. It's fairly cheap.

[SharkWhisperer]

You might try recrystallizing it? It's possible that it has a significant amount of crap, both soluble and insoluble, in it that could hamper it's oxidizing utility. Check out some KNO₃ solubility curves (in water) posted in previous threads or easily downloaded online. You can get a substantial amount into solution at boiling temps and it falls precipitates out of solution pretty easily at low temps where it's relatively insoluble.

 

But unless you're in a country where you cannot easily buy cheap KNO₃ or are a minor (you're using expensive Spectricide??), good KNO₃ is available at very reasonable prices ($2-3/lb at <10lb hobbyist quantities; cheaper for more), even premilled, from several US fireworking chem vendors. That's the route I'd take, if available, instead of tinkering around with time-consuming recrystaliation issues.

 

For pure nitrate fertilizer, the NPK ratio should be 13:0:44. Any deviation from that might give a clue as to what else might be in there. But you're using Hi-Yield Stump Remover, not fertilizer... Hmmm....they say it's 95-99% KNO₃. That 5% inert stuff could be problematic. If it's non-hazardous typical contaminants in small quantities it won't appear on the MSDS. Have you searched the forum or web to see if others have had similar issues with the same stuff (and potential solutions).

 

Anyways, here's a link with crystal clear instructions for recrystallizing nitrate from tainted products...http://www.nakka-rocketry.net/knpurify.html . Not at all difficult.

[dom]

Thanks, I might try recrystalizing some and see if that makes a difference.

For buying, what US pyro chem vendors would you recommend? Premilled would be nice because I just have a small blender, no mill. I know skylighter and pyrochemsource, but those seem expensive or have expensive shipping.

Here's some I found:

https://mbferts.com/products/haifa-multi-k-greenhouse-potassium-nitrate-saltpeter-kno3

Is this good enough quality? What vendors do you use?

Thanks

[Carbon796]

Yes, GG & tech grade are very usable products.

[Arthur]

I've used Haifa KNO3 before satisfactorily

 

Some uses get different supplied chems sometimes. I know people who use stump remover for pot nitrate and others who get sodium metabisulphite in a bottle labelled stump remover you have to check what each brand uses for each purpose.

[MadMat]

I buy my KNO3 from dudadiesel.com. They sell 1#, 5#, 10# and 50# bags. The price for the 10 pound bag is #20.74 (plus shipping). They say it is 99.8% pure and it has always worked great for me

[dom]

I buy my KNO3 from dudadiesel.com. They sell 1#, 5#, 10# and 50# bags. The price for the 10 pound bag is #20.74 (plus shipping). They say it is 99.8% pure and it has always worked great for me

When I looked there I only found prilled. Do they have milled too?

[dom]

You might try recrystallizing it? It's possible that it has a significant amount of crap, both soluble and insoluble, in it that could hamper it's oxidizing utility. Check out some KNO₃ solubility curves (in water) posted in previous threads or easily downloaded online. You can get a substantial amount into solution at boiling temps and it falls precipitates out of solution pretty easily at low temps where it's relatively insoluble.

 

But unless you're in a country where you cannot easily buy cheap KNO₃ or are a minor (you're using expensive Spectricide??), good KNO₃ is available at very reasonable prices ($2-3/lb at <10lb hobbyist quantities; cheaper for more), even premilled, from several US fireworking chem vendors. That's the route I'd take, if available, instead of tinkering around with time-consuming recrystaliation issues.

 

For pure nitrate fertilizer, the NPK ratio should be 13:0:44. Any deviation from that might give a clue as to what else might be in there. But you're using Hi-Yield Stump Remover, not fertilizer... Hmmm....they say it's 95-99% KNO₃. That 5% inert stuff could be problematic. If it's non-hazardous typical contaminants in small quantities it won't appear on the MSDS. Have you searched the forum or web to see if others have had similar issues with the same stuff (and potential solutions).

 

Anyways, here's a link with crystal clear instructions for recrystallizing nitrate from tainted products...http://www.nakka-rocketry.net/knpurify.html . Not at all difficult.

Yes, I'm 17, but I think my parents would let me order some online. I just wanted some quickly to test with.

I only have a blender, no mill, so I can only grind one chemical at a time (and even then its not very fine). What vendor would you recommend that has cheap milled KNO3? Or any workarounds for not having a mill.

[SharkWhisperer]

Yes, I'm 17, but I think my parents would let me order some online. I just wanted some quickly to test with.

I only have a blender, no mill, so I can only grind one chemical at a time (and even then its not very fine). What vendor would you recommend that has cheap milled KNO3? Or any workarounds for not having a mill.

Both fireworkscookbook.com and pyrochemsource.com both have milled high-quality potassium nitrate for $3/pound. But if you're planning on making fast BP, you're ultimately going to meed a hot charcoal (preferably homemade) and a ball mill. There are many, many threads on this site related to making good BP. FWC has unmilled (granular like table sugar) for $2/lb. Many other places (you'll find them in a search; buy direct, not Ebay/Amazon) sell great potassium nitrate for reasonable prices. You'll probably pay more for shipping than the cost of a few pounds of chems...

[MadMat]

Take it from someone that has tried every possible way of making BP at one time or another. The only way to make good quality black powder consistantly is with a ballmill. As far as prilled KNO3, a blender works wonders with it! I feel I should warn you right now though. Get more than one blender. I got mine at resale shops (Good Will ect.) I use one for oxidizers and one for fuels. Not to mention, I have a third one in reserve for anything that needs to be kept separate from other chemicals (this one gets cleaned thoroughly after each use). It is a matter of safety that shouldn't be taken lightly!!! As for my ballmill, I made it with some simple parts from a hardware store and a motor from American Science and Surplus. My total cost was under $20. It is not designed like most ballmills converted from rock tumblers and is limited to about 150 grams per batch, but it has made literally hundreds of batches without any problems.

[MadMat]

I also corn my BP. I made a cylinder and piston for pressing the milldust into pucks out of a 2" piece of sch30 pvc pipe. I cast the pistons out of fiberglass resin right into the pipe (after smearing a thin coat of vaseline inside the pipe as a release agent. My first set of pistons cracked after only a couple uses. My second set had pieces of chopped up fiberglass matting and they have worked for me for 4 years now. There is a bit of clearance between the pistons and the cylinder because of shrinkage, but that is a good thing as you want air to escape as you press. I made my first press out of two pieces of 8" iron "U" channel that I bought at a recycling yard for $4.00 and some 3/4" threaded rod. Add a bottle jack and a 3/4" plexiglass safety shield and you have a good working press.

[dom]

I also corn my BP. I made a cylinder and piston for pressing the milldust into pucks out of a 2" piece of sch30 pvc pipe. I cast the pistons out of fiberglass resin right into the pipe (after smearing a thin coat of vaseline inside the pipe as a release agent. My first set of pistons cracked after only a couple uses. My second set had pieces of chopped up fiberglass matting and they have worked for me for 4 years now. There is a bit of clearance between the pistons and the cylinder because of shrinkage, but that is a good thing as you want air to escape as you press. I made my first press out of two pieces of 8" iron "U" channel that I bought at a recycling yard for $4.00 and some 3/4" threaded rod. Add a bottle jack and a 3/4" plexiglass safety shield and you have a good working press

Could I see some photos of your mill and other equipment for reference/inspiration? Thanks for all the advice so far.

[Delloman]

I have 2 https://www.amazon.com/dp/B07J4NTJ86?ref=ppx_pop_mob_ap_share but save for a ballmill I use it so much more fireworkscookbook.com will be selling 1,2, and 3 jar options within the next 30 days i have an upgraded rebal from woodys and will be up grading from that to a 3 Jar option with Stainless steel media in 3 of my 5 jars get more jars and media then you can run so you can keep them running as you empty and fill the others